Introduces Bytes class (#1019)

This introduces a new `Bytes` standard library class, for working with
binary data.

* Add Bytes class to the standard library
* Change CLI to eval `output.bytes`
* Change code generators to map Bytes to respective underlying type
* Add subscript and concat operator support
* Add binary encoding for Bytes
* Add PCF and Plist rendering for Bytes

Co-authored-by: Kushal Pisavadia <kushi.p@gmail.com>

docs/modules/ROOT/partials/component-attributes.adoc

@@ -138,6 +138,7 @@ endif::[]
 :uri-stdlib-Function3: {uri-stdlib-baseModule}/Function3
 :uri-stdlib-Function4: {uri-stdlib-baseModule}/Function4
 :uri-stdlib-Function5: {uri-stdlib-baseModule}/Function5
+:uri-stdlib-Bytes: {uri-stdlib-baseModule}/Bytes
 :uri-stdlib-Resource: {uri-stdlib-baseModule}/Resource
 :uri-stdlib-outputFiles: {uri-stdlib-baseModule}/ModuleOutput#files
 

docs/modules/bindings-specification/pages/binary-encoding.adoc

@@ -161,6 +161,24 @@ The array's length is the number of slots that are filled. For example, xref:{ur
 |
 |
 |
+
+|link:{uri-stdlib-Function}[Function]
+|`0xE`
+|
+|
+|
+|
+|
+|
+
+|link:{uri-stdlib-Bytes}[Bytes]
+|`0xF`
+|link:{uri-messagepack-bin}[bin]
+|Binary contents
+|
+|
+|
+|
 |===
 
 [[object-members]]

docs/modules/language-reference/pages/index.adoc

@@ -3684,6 +3684,41 @@ res5 = map.getOrNull("Falcon") // <5>
 <4> result: `2`
 <5> result: `null`
 
+[[bytes]]
+=== Bytes
+
+A value of type `Bytes` is a sequence of `UInt8` elements.
+
+`Bytes` can be constructed by passing byte values into the constructor.
+
+[source,pkl]
+----
+bytes1 = Bytes(0xff, 0x00, 0x3f) // <1>
+bytes2 = Bytes() // <2>
+----
+<1> Result: a `Bytes` with 3 elements
+<2> Result: an empty `Bytes`
+
+`Bytes` can also be constructed from a base64-encoded string, via `base64DecodedBytes`:
+
+[source,pkl]
+----
+bytes3 = "cGFycm90".base64DecodedBytes // <1>
+----
+<1> Result: `Bytes(112, 97, 114, 114, 111, 116)`
+
+==== `Bytes` vs `List<UInt8>`
+
+`Bytes` is similar to `List<UInt8>` in that they are both sequences of `UInt8` elements.
+However, they are semantically distinct.
+`Bytes` represent binary data, and is typically rendered differently.
+For example, they are rendered as `<data>` tags when using `PListRenderer`.
+
+`Bytes` also have different performance characteristics; a value of type `Bytes` tends to be managed as a contiguous memory block.
+Thus, they are more compact and consume less memory.
+However, they are not optimized for transformations.
+For example, given two values of size `M` and `N`, concatenating two `Bytes` values allocates O(M + N) space, whereas concatenating two `List` values allocates O(1) space.
+
 [[regular-expressions]]
 === Regular Expressions
 
@@ -4671,6 +4706,10 @@ The following types are iterable:
 |entry key (`Key`)
 |entry value (`Value`)
 
+|`Bytes`
+|element index (`Int`)
+|element value (`UInt8`)
+
 |`Listing<Element>`
 |element index (`Int`)
 |element value (`Element`)
@@ -4751,6 +4790,9 @@ The following table describes how different iterables turn into object members:
 
 | `IntSeq`
 | Element
+
+| `Bytes`
+| Element
 |===
 
 These types can only be spread into enclosing objects that support that member type.

pkl-cli/src/main/kotlin/org/pkl/cli/CliEvaluator.kt

@@ -16,20 +16,23 @@
 package org.pkl.cli
 
 import java.io.File
-import java.io.Reader
+import java.io.InputStream
-import java.io.Writer
+import java.io.OutputStream
 import java.net.URI
+import java.nio.charset.StandardCharsets
 import java.nio.file.Files
 import java.nio.file.Path
 import java.nio.file.StandardOpenOption
 import kotlin.io.path.createParentDirectories
 import kotlin.io.path.exists
 import kotlin.io.path.isDirectory
+import kotlin.io.path.writeBytes
 import org.pkl.commons.cli.CliCommand
 import org.pkl.commons.cli.CliException
 import org.pkl.commons.currentWorkingDir
 import org.pkl.commons.writeString
 import org.pkl.core.Closeables
+import org.pkl.core.Evaluator
 import org.pkl.core.EvaluatorBuilder
 import org.pkl.core.ModuleSource
 import org.pkl.core.PklException
@@ -48,8 +51,8 @@ constructor(
   private val options: CliEvaluatorOptions,
   // use System.{in,out}() rather than System.console()
   // because the latter returns null when output is sent through a unix pipe
-  private val consoleReader: Reader = System.`in`.reader(),
+  private val inputStream: InputStream = System.`in`,
-  private val consoleWriter: Writer = System.out.writer(),
+  private val outputStream: OutputStream = System.out,
 ) : CliCommand(options.base) {
   /**
    * Output files for the modules to be evaluated. Returns `null` if `options.outputPath` is `null`
@@ -84,11 +87,12 @@ constructor(
   /**
    * Evaluates source modules according to [options].
    *
-   * If [CliEvaluatorOptions.outputPath] is set, each module's `output.text` is written to the
+   * If [CliEvaluatorOptions.outputPath] is set, each module's `output.bytes` is written to the
-   * module's [output file][outputFiles]. If [CliEvaluatorOptions.multipleFileOutputPath] is set,
+   * module's [output file][outputFiles].
-   * each module's `output.files` are written to the module's [output directory][outputDirectories].
+   *
-   * Otherwise, each module's `output.text` is written to [consoleWriter] (which defaults to
+   * If [CliEvaluatorOptions.multipleFileOutputPath] is set, each module's `output.files` are
-   * standard out).
+   * written to the module's [output directory][outputDirectories]. Otherwise, each module's
+   * `output.bytes` is written to [outputStream] (which defaults to standard out).
    *
    * Throws [CliException] in case of an error.
    */
@@ -139,10 +143,29 @@ constructor(
     }
   }
 
-  /** Renders each module's `output.text`, writing it to the specified output file. */
+  private fun Evaluator.writeOutput(moduleSource: ModuleSource, writeTo: Path): Boolean {
+    if (options.expression == null) {
+      val bytes = evaluateOutputBytes(moduleSource)
+      writeTo.writeBytes(bytes)
+      return bytes.isNotEmpty()
+    }
+    val text = evaluateExpressionString(moduleSource, options.expression)
+    writeTo.writeString(text)
+    return text.isNotEmpty()
+  }
+
+  private fun Evaluator.evalOutput(moduleSource: ModuleSource): ByteArray {
+    if (options.expression == null) {
+      return evaluateOutputBytes(moduleSource)
+    }
+    return evaluateExpressionString(moduleSource, options.expression)
+      .toByteArray(StandardCharsets.UTF_8)
+  }
+
+  /** Renders each module's `output.bytes`, writing it to the specified output file. */
   private fun writeOutput(builder: EvaluatorBuilder) {
     val evaluator = builder.setOutputFormat(options.outputFormat).build()
-    evaluator.use {
+    evaluator.use { ev ->
       val outputFiles = fileOutputPaths
       if (outputFiles != null) {
         // files that we've written non-empty output to
@@ -151,18 +174,18 @@ constructor(
         val writtenFiles = mutableSetOf<Path>()
 
         for ((moduleUri, outputFile) in outputFiles) {
-          val moduleSource = toModuleSource(moduleUri, consoleReader)
+          val moduleSource = toModuleSource(moduleUri, inputStream)
-          val output = evaluator.evaluateExpressionString(moduleSource, options.expression)
           if (Files.isDirectory(outputFile)) {
             throw CliException(
               "Output file `$outputFile` is a directory. " +
                 "Did you mean `--multiple-file-output-path`?"
             )
           }
+          val output = ev.evalOutput(moduleSource)
           outputFile.createParentDirectories()
           if (!writtenFiles.contains(outputFile)) {
             // write file even if output is empty to overwrite output from previous runs
-            outputFile.writeString(output)
+            outputFile.writeBytes(output)
             if (output.isNotEmpty()) {
               writtenFiles.add(outputFile)
             }
@@ -174,34 +197,49 @@ constructor(
                 StandardOpenOption.WRITE,
                 StandardOpenOption.APPEND,
               )
-              outputFile.writeString(
+              outputFile.writeBytes(output, StandardOpenOption.WRITE, StandardOpenOption.APPEND)
-                output,
-                Charsets.UTF_8,
-                StandardOpenOption.WRITE,
-                StandardOpenOption.APPEND,
-              )
             }
           }
         }
       } else {
         var outputWritten = false
         for (moduleUri in options.base.normalizedSourceModules) {
-          val moduleSource = toModuleSource(moduleUri, consoleReader)
+          val moduleSource = toModuleSource(moduleUri, inputStream)
-          val output = evaluator.evaluateExpressionString(moduleSource, options.expression)
+          if (options.expression != null) {
-          if (output.isNotEmpty()) {
+            val output = evaluator.evaluateExpressionString(moduleSource, options.expression)
-            if (outputWritten) consoleWriter.appendLine(options.moduleOutputSeparator)
+            if (output.isNotEmpty()) {
-            consoleWriter.write(output)
+              if (outputWritten) outputStream.writeLine(options.moduleOutputSeparator)
-            consoleWriter.flush()
+              outputStream.writeText(output)
-            outputWritten = true
+              outputStream.flush()
+              outputWritten = true
+            }
+          } else {
+            val outputBytes = evaluator.evaluateOutputBytes(moduleSource)
+            if (outputBytes.isNotEmpty()) {
+              if (outputWritten) outputStream.writeLine(options.moduleOutputSeparator)
+              outputStream.write(outputBytes)
+              outputStream.flush()
+              outputWritten = true
+            }
           }
         }
       }
     }
   }
 
-  private fun toModuleSource(uri: URI, reader: Reader) =
+  private fun OutputStream.writeText(text: String) = write(text.toByteArray())
-    if (uri == VmUtils.REPL_TEXT_URI) ModuleSource.create(uri, reader.readText())
+
-    else ModuleSource.uri(uri)
+  private fun OutputStream.writeLine(text: String) {
+    writeText(text)
+    writeText("\n")
+  }
+
+  private fun toModuleSource(uri: URI, reader: InputStream) =
+    if (uri == VmUtils.REPL_TEXT_URI) {
+      ModuleSource.create(uri, reader.readAllBytes().toString(StandardCharsets.UTF_8))
+    } else {
+      ModuleSource.uri(uri)
+    }
 
   private fun checkPathSpec(pathSpec: String) {
     val illegal = pathSpec.indexOfFirst { IoUtils.isReservedFilenameChar(it) && it != '/' }
@@ -223,7 +261,7 @@ constructor(
       if (outputDir.exists() && !outputDir.isDirectory()) {
         throw CliException("Output path `$outputDir` exists and is not a directory.")
       }
-      val moduleSource = toModuleSource(moduleUri, consoleReader)
+      val moduleSource = toModuleSource(moduleUri, inputStream)
       val output = evaluator.evaluateOutputFiles(moduleSource)
       for ((pathSpec, fileOutput) in output) {
         checkPathSpec(pathSpec)
@@ -247,12 +285,12 @@ constructor(
         }
         writtenFiles[realPath] = OutputFile(pathSpec, moduleUri)
         realPath.createParentDirectories()
-        realPath.writeString(fileOutput.text)
+        realPath.writeBytes(fileOutput.bytes)
-        consoleWriter.write(
+        outputStream.writeText(
           IoUtils.relativize(resolvedPath, currentWorkingDir).toString() +
             IoUtils.getLineSeparator()
         )
-        consoleWriter.flush()
+        outputStream.flush()
       }
     }
   }

pkl-cli/src/main/kotlin/org/pkl/cli/CliEvaluatorOptions.kt

@@ -74,9 +74,9 @@ data class CliEvaluatorOptions(
    *
    * If set, the said expression is evaluated under the context of the enclosing module.
    *
-   * If unset, the module's `output.text` property evaluated.
+   * If unset, the module's `output.bytes` property is evaluated.
    */
-  val expression: String = "output.text",
+  val expression: String? = null,
 ) {
 
   companion object {

pkl-cli/src/test/kotlin/org/pkl/cli/CliEvaluatorTest.kt

@@ -18,10 +18,11 @@ package org.pkl.cli
 import com.github.tomakehurst.wiremock.client.WireMock.*
 import com.github.tomakehurst.wiremock.junit5.WireMockRuntimeInfo
 import com.github.tomakehurst.wiremock.junit5.WireMockTest
-import java.io.StringReader
+import java.io.ByteArrayInputStream
-import java.io.StringWriter
+import java.io.ByteArrayOutputStream
 import java.net.ServerSocket
 import java.net.URI
+import java.nio.charset.StandardCharsets
 import java.nio.file.Files
 import java.nio.file.Path
 import java.time.Duration
@@ -29,22 +30,20 @@ import java.util.regex.Pattern
 import kotlin.io.path.*
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatCode
-import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.*
-import org.junit.jupiter.api.AfterEach
-import org.junit.jupiter.api.Disabled
-import org.junit.jupiter.api.Test
-import org.junit.jupiter.api.assertThrows
 import org.junit.jupiter.api.condition.DisabledOnOs
 import org.junit.jupiter.api.condition.EnabledOnOs
 import org.junit.jupiter.api.condition.OS
 import org.junit.jupiter.api.io.TempDir
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.EnumSource
-import org.pkl.commons.*
 import org.pkl.commons.cli.CliBaseOptions
 import org.pkl.commons.cli.CliException
+import org.pkl.commons.readString
 import org.pkl.commons.test.FileTestUtils
 import org.pkl.commons.test.PackageServer
+import org.pkl.commons.toPath
+import org.pkl.commons.writeString
 import org.pkl.core.OutputFormat
 import org.pkl.core.SecurityManagers
 import org.pkl.core.util.IoUtils
@@ -157,7 +156,6 @@ person:
       )
 
     assertThat(outputFiles).hasSize(1)
-    @Suppress("HttpUrlsUsage")
     checkOutputFile(
       outputFiles[0],
       "test.plist",
@@ -469,8 +467,8 @@ result = someLib.x
 
   @Test
   fun `take input from stdin`() {
-    val stdin = StringReader(defaultContents)
+    val stdin = ByteArrayInputStream(defaultContents.toByteArray(StandardCharsets.UTF_8))
-    val stdout = StringWriter()
+    val stdout = ByteArrayOutputStream()
     val evaluator =
       CliEvaluator(
         CliEvaluatorOptions(
@@ -481,7 +479,8 @@ result = someLib.x
         stdout,
       )
     evaluator.run()
-    assertThat(stdout.toString().trim()).isEqualTo(defaultContents.replace("20 + 10", "30").trim())
+    assertThat(stdout.toString(StandardCharsets.UTF_8).trim())
+      .isEqualTo(defaultContents.replace("20 + 10", "30").trim())
   }
 
   @Test
@@ -1101,9 +1100,9 @@ result = someLib.x
         CliBaseOptions(sourceModules = listOf(moduleUri), workingDir = tempDir),
         expression = "foo",
       )
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString())
+    assertThat(buffer.toString(StandardCharsets.UTF_8))
       .isEqualTo(
         """
       new Dynamic { bar = 1 }
@@ -1132,9 +1131,9 @@ result = someLib.x
         CliBaseOptions(sourceModules = listOf(moduleUri), workingDir = tempDir),
         expression = "person",
       )
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString()).isEqualTo("Person(Frodo)")
+    assertThat(buffer.toString(StandardCharsets.UTF_8)).isEqualTo("Person(Frodo)")
   }
 
   @Test
@@ -1154,9 +1153,10 @@ result = someLib.x
         CliBaseOptions(sourceModules = listOf(moduleUri), workingDir = tempDir),
         expression = "person",
       )
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString()).isEqualTo("new Dynamic { friend { name = \"Bilbo\" } }")
+    assertThat(buffer.toString(StandardCharsets.UTF_8))
+      .isEqualTo("new Dynamic { friend { name = \"Bilbo\" } }")
   }
 
   @Test
@@ -1182,9 +1182,9 @@ result = someLib.x
       CliEvaluatorOptions(
         CliBaseOptions(sourceModules = listOf(moduleUri), workingDir = tempDir, noProject = true)
       )
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString()).isEqualTo("res = 1\n")
+    assertThat(buffer.toString(StandardCharsets.UTF_8)).isEqualTo("res = 1\n")
   }
 
   @Test
@@ -1215,9 +1215,9 @@ result = someLib.x
     )
     val options =
       CliEvaluatorOptions(CliBaseOptions(sourceModules = listOf(moduleUri), workingDir = tempDir))
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString())
+    assertThat(buffer.toString(StandardCharsets.UTF_8))
       .isEqualTo(
         """
       res {
@@ -1242,7 +1242,7 @@ result = someLib.x
     """
           .trimIndent(),
       )
-    val buffer = StringWriter()
+    val buffer = ByteArrayOutputStream()
     val options =
       CliEvaluatorOptions(
         CliBaseOptions(
@@ -1254,8 +1254,8 @@ result = someLib.x
           testPort = packageServer.port,
         )
       )
-    CliEvaluator(options, consoleWriter = buffer).run()
+    CliEvaluator(options, outputStream = buffer).run()
-    assertThat(buffer.toString())
+    assertThat(buffer.toString(StandardCharsets.UTF_8))
       .isEqualTo(
         """
       res {
@@ -1590,10 +1590,10 @@ result = someLib.x
   }
 
   private fun evalToConsole(options: CliEvaluatorOptions): String {
-    val reader = StringReader("")
+    val reader = ByteArrayInputStream(byteArrayOf())
-    val writer = StringWriter()
+    val writer = ByteArrayOutputStream()
     CliEvaluator(options, reader, writer).run()
-    return writer.toString()
+    return writer.toString(StandardCharsets.UTF_8)
   }
 
   private fun checkOutputFile(file: Path, name: String, contents: String) {

pkl-codegen-java/src/main/kotlin/org/pkl/codegen/java/JavaCodeGenerator.kt

@@ -342,13 +342,22 @@ class JavaCodeGenerator(
 
       var builderSize = 50
       val appendBuilder = CodeBlock.builder()
-      for (propertyName in allProperties.keys) {
+      for ((propertyName, property) in allProperties) {
         builderSize += 50
-        appendBuilder.addStatement(
+        if (property.type.isBytesClass) {
-          "appendProperty(builder, \$S, this.\$N)",
+          appendBuilder.addStatement(
-          propertyName,
+            "appendProperty(builder, \$S, \$T.toString(this.\$N))",
-          propertyName,
+            propertyName,
-        )
+            Arrays::class.java,
+            propertyName,
+          )
+        } else {
+          appendBuilder.addStatement(
+            "appendProperty(builder, \$S, this.\$N)",
+            propertyName,
+            propertyName,
+          )
+        }
       }
 
       builder
@@ -725,6 +734,9 @@ class JavaCodeGenerator(
     }
   }
 
+  private val PType.isBytesClass: Boolean
+    get() = this is PType.Class && this.pClass.info == PClassInfo.Bytes
+
   private fun PType.toJavaPoetName(nullable: Boolean = false, boxed: Boolean = false): TypeName =
     when (this) {
       PType.UNKNOWN -> OBJECT.nullableIf(nullable)
@@ -744,6 +756,7 @@ class JavaCodeGenerator(
           PClassInfo.Float -> TypeName.DOUBLE.boxIf(boxed).nullableIf(nullable)
           PClassInfo.Duration -> DURATION.nullableIf(nullable)
           PClassInfo.DataSize -> DATA_SIZE.nullableIf(nullable)
+          PClassInfo.Bytes -> ArrayTypeName.of(TypeName.BYTE)
           PClassInfo.Pair ->
             ParameterizedTypeName.get(
                 PAIR,

pkl-codegen-java/src/test/kotlin/org/pkl/codegen/java/JavaCodeGeneratorTest.kt

@@ -87,6 +87,7 @@ class JavaCodeGeneratorTest {
           any: Any
           nonNull: NonNull
           enum: Direction
+          bytes: Bytes
         }
 
         class Other {
@@ -202,6 +203,7 @@ class JavaCodeGeneratorTest {
             name = pigeon
           }
           _enum = north
+          bytes = [1, 2, 3, 4]
         }
       """
           .trimIndent()
@@ -542,6 +544,7 @@ class JavaCodeGeneratorTest {
     assertThat(readProperty(propertyTypes, "regex")).isInstanceOf(Pattern::class.java)
     assertThat(readProperty(propertyTypes, "any")).isEqualTo(other)
     assertThat(readProperty(propertyTypes, "nonNull")).isEqualTo(other)
+    assertThat(readProperty(propertyTypes, "bytes")).isEqualTo(byteArrayOf(1, 2, 3, 4))
   }
 
   private fun readProperty(obj: Any, property: String): Any? =
@@ -2313,6 +2316,7 @@ class JavaCodeGeneratorTest {
         other,
         other,
         enumValue,
+        byteArrayOf(1, 2, 3, 4),
       )
 
     return other to propertyTypes

pkl-codegen-java/src/test/resources/org/pkl/codegen/java/PropertyTypes.jva

@@ -4,6 +4,7 @@ import java.lang.Object;
 import java.lang.Override;
 import java.lang.String;
 import java.lang.StringBuilder;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -86,6 +87,8 @@ public final class Mod {
 
     public final @NonNull Direction _enum;
 
+    public final byte[] bytes;
+
     public PropertyTypes(@Named("boolean") boolean _boolean, @Named("int") long _int,
         @Named("float") double _float, @Named("string") @NonNull String string,
         @Named("duration") @NonNull Duration duration,
@@ -106,7 +109,7 @@ public final class Mod {
         @Named("container2") @NonNull Map<@NonNull String, @NonNull Other> container2,
         @Named("other") @NonNull Other other, @Named("regex") @NonNull Pattern regex,
         @Named("any") Object any, @Named("nonNull") @NonNull Object nonNull,
-        @Named("enum") @NonNull Direction _enum) {
+        @Named("enum") @NonNull Direction _enum, @Named("bytes") byte[] bytes) {
       this._boolean = _boolean;
       this._int = _int;
       this._float = _float;
@@ -134,114 +137,119 @@ public final class Mod {
       this.any = any;
       this.nonNull = nonNull;
       this._enum = _enum;
+      this.bytes = bytes;
     }
 
     public PropertyTypes withBoolean(boolean _boolean) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withInt(long _int) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withFloat(double _float) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withString(@NonNull String string) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withDuration(@NonNull Duration duration) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withDurationUnit(@NonNull DurationUnit durationUnit) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withDataSize(@NonNull DataSize dataSize) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withDataSizeUnit(@NonNull DataSizeUnit dataSizeUnit) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withNullable(String nullable) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withNullable2(String nullable2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withPair(@NonNull Pair<Object, Object> pair) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withPair2(@NonNull Pair<@NonNull String, @NonNull Other> pair2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withColl(@NonNull Collection<Object> coll) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withColl2(@NonNull Collection<@NonNull Other> coll2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withList(@NonNull List<Object> list) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withList2(@NonNull List<@NonNull Other> list2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withSet(@NonNull Set<Object> set) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withSet2(@NonNull Set<@NonNull Other> set2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withMap(@NonNull Map<Object, Object> map) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withMap2(@NonNull Map<@NonNull String, @NonNull Other> map2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withContainer(@NonNull Map<Object, Object> container) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withContainer2(@NonNull Map<@NonNull String, @NonNull Other> container2) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withOther(@NonNull Other other) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withRegex(@NonNull Pattern regex) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withAny(Object any) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withNonNull(@NonNull Object nonNull) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     public PropertyTypes withEnum(@NonNull Direction _enum) {
-      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum);
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
+    }
+
+    public PropertyTypes withBytes(byte[] bytes) {
+      return new PropertyTypes(_boolean, _int, _float, string, duration, durationUnit, dataSize, dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map, map2, container, container2, other, regex, any, nonNull, _enum, bytes);
     }
 
     @Override
@@ -277,6 +285,7 @@ public final class Mod {
       if (!Objects.equals(this.any, other.any)) return false;
       if (!Objects.equals(this.nonNull, other.nonNull)) return false;
       if (!Objects.equals(this._enum, other._enum)) return false;
+      if (!Objects.equals(this.bytes, other.bytes)) return false;
       return true;
     }
 
@@ -310,12 +319,13 @@ public final class Mod {
       result = 31 * result + Objects.hashCode(this.any);
       result = 31 * result + Objects.hashCode(this.nonNull);
       result = 31 * result + Objects.hashCode(this._enum);
+      result = 31 * result + Objects.hashCode(this.bytes);
       return result;
     }
 
     @Override
     public String toString() {
-      StringBuilder builder = new StringBuilder(1400);
+      StringBuilder builder = new StringBuilder(1450);
       builder.append(PropertyTypes.class.getSimpleName()).append(" {");
       appendProperty(builder, "_boolean", this._boolean);
       appendProperty(builder, "_int", this._int);
@@ -344,6 +354,7 @@ public final class Mod {
       appendProperty(builder, "any", this.any);
       appendProperty(builder, "nonNull", this.nonNull);
       appendProperty(builder, "_enum", this._enum);
+      appendProperty(builder, "bytes", Arrays.toString(this.bytes));
       builder.append("\n}");
       return builder.toString();
     }

pkl-codegen-kotlin/src/main/kotlin/org/pkl/codegen/kotlin/KotlinCodeGenerator.kt

@@ -226,6 +226,9 @@ class KotlinCodeGenerator(
     fun PClass.Property.isRegex(): Boolean =
       (this.type as? PType.Class)?.pClass?.info == PClassInfo.Regex
 
+    fun PClass.Property.isByteArray(): Boolean =
+      (this.type as? PType.Class)?.pClass?.info == PClassInfo.Bytes
+
     fun generateConstructor(): FunSpec {
       val builder = FunSpec.constructorBuilder()
       for ((name, property) in allProperties) {
@@ -302,12 +305,20 @@ class KotlinCodeGenerator(
           .addStatement("other as %T", kotlinPoetClassName)
 
       for ((propertyName, property) in allProperties) {
-        val accessor = if (property.isRegex()) "%N.pattern" else "%N"
+        if (property.isByteArray()) {
-        builder.addStatement(
+          builder.addStatement(
-          "if (this.$accessor != other.$accessor) return false",
+            "if (!this.%N.contentEquals(other.%N)) return false",
-          propertyName,
+            propertyName,
-          propertyName,
+            propertyName,
-        )
+          )
+        } else {
+          val accessor = if (property.isRegex()) "%N.pattern" else "%N"
+          builder.addStatement(
+            "if (this.$accessor != other.$accessor) return false",
+            propertyName,
+            propertyName,
+          )
+        }
       }
 
       builder.addStatement("return true")
@@ -322,14 +333,18 @@ class KotlinCodeGenerator(
           .addStatement("var result = 1")
 
       for ((propertyName, property) in allProperties) {
-        val accessor = if (property.isRegex()) "this.%N.pattern" else "this.%N"
+        if (property.isByteArray()) {
-        // use Objects.hashCode() because Kotlin's Any?.hashCode()
+          builder.addStatement("result = 31 * result + this.%N.contentHashCode()", propertyName)
-        // doesn't work for platform types (will get NPE if null)
+        } else {
-        builder.addStatement(
+          val accessor = if (property.isRegex()) "this.%N.pattern" else "this.%N"
-          "result = 31 * result + %T.hashCode($accessor)",
+          // use Objects.hashCode() because Kotlin's Any?.hashCode()
-          Objects::class,
+          // doesn't work for platform types (will get NPE if null)
-          propertyName,
+          builder.addStatement(
-        )
+            "result = 31 * result + %T.hashCode($accessor)",
+            Objects::class,
+            propertyName,
+          )
+        }
       }
 
       builder.addStatement("return result")
@@ -347,10 +362,15 @@ class KotlinCodeGenerator(
             .apply {
               add("%L", pClass.toKotlinPoetName().simpleName)
               add("(")
-              for ((index, propertyName) in allProperties.keys.withIndex()) {
+              for ((index, entry) in allProperties.entries.withIndex()) {
+                val (propertyName, property) = entry
                 add(if (index == 0) "%L" else ", %L", propertyName)
-                add("=$")
+                if (property.isByteArray()) {
-                add("%N", propertyName)
+                  add("=\${%T.toString(%L)}", Arrays::class, propertyName)
+                } else {
+                  add("=$")
+                  add("%N", propertyName)
+                }
               }
               add(")")
             }
@@ -488,16 +508,16 @@ class KotlinCodeGenerator(
         builder.addKdoc(renderAsKdoc(docComment))
       }
 
-      var hasRegex = false
+      var hasRegexOrByteArray = false
       for ((name, property) in properties) {
-        hasRegex = hasRegex || property.isRegex()
+        hasRegexOrByteArray = hasRegexOrByteArray || property.isRegex() || property.isByteArray()
         builder.addProperty(generateProperty(name, property))
       }
 
-      // kotlin.text.Regex (and java.util.regex.Pattern) defines equality as identity.
+      // Regex and ByteArray define equaltiy as identity.
-      // To match Pkl semantics and compare regexes by their String pattern,
+      // To match Pkl semantics, override equals and hashCode if the data class has a property of
-      // override equals and hashCode if the data class has a property of type Regex.
+      // type Regex or ByteArray.
-      if (hasRegex) {
+      if (hasRegexOrByteArray) {
         builder.addFunction(generateEqualsMethod()).addFunction(generateHashCodeMethod())
       }
 
@@ -632,6 +652,7 @@ class KotlinCodeGenerator(
           PClassInfo.Float -> DOUBLE
           PClassInfo.Duration -> DURATION
           PClassInfo.DataSize -> DATA_SIZE
+          PClassInfo.Bytes -> BYTE_ARRAY
           PClassInfo.Pair ->
             KOTLIN_PAIR.parameterizedBy(
               if (typeArguments.isEmpty()) ANY_NULL else typeArguments[0].toKotlinPoetName(),

pkl-codegen-kotlin/src/test/kotlin/org/pkl/codegen/kotlin/KotlinCodeGeneratorTest.kt

@@ -120,6 +120,7 @@ class KotlinCodeGeneratorTest {
           any: Any
           nonNull: NonNull
           enum: Direction
+          bytes: Bytes
         }
 
         open class Other {
@@ -193,7 +194,6 @@ class KotlinCodeGeneratorTest {
   @Test
   fun testToString() {
     val (_, propertyTypes) = instantiateOtherAndPropertyTypes()
-
     assertThat(propertyTypes.toString())
       .isEqualTo(
         """PropertyTypes(boolean=true, int=42, float=42.3, string=string, duration=5.min, """ +
@@ -204,7 +204,8 @@ class KotlinCodeGeneratorTest {
           """set2=[Other(name=pigeon)], map={1=one, 2=two}, map2={one=Other(name=pigeon), """ +
           """two=Other(name=pigeon)}, container={1=one, 2=two}, container2={one=Other(name=pigeon), """ +
           """two=Other(name=pigeon)}, other=Other(name=pigeon), regex=(i?)\w*, any=Other(name=pigeon), """ +
-          """nonNull=Other(name=pigeon), enum=north)"""
+          """nonNull=Other(name=pigeon), enum=north, """ +
+          """bytes=[1, 2, 3, 4])"""
       )
   }
 
@@ -412,6 +413,7 @@ class KotlinCodeGeneratorTest {
     assertThat(readProperty(propertyTypes, "regex")).isInstanceOf(Regex::class.java)
     assertThat(readProperty(propertyTypes, "any")).isEqualTo(other)
     assertThat(readProperty(propertyTypes, "nonNull")).isEqualTo(other)
+    assertThat(readProperty(propertyTypes, "bytes")).isEqualTo(byteArrayOf(1, 2, 3, 4))
   }
 
   private fun readProperty(receiver: Any, name: String): Any? {
@@ -571,6 +573,25 @@ class KotlinCodeGeneratorTest {
       .contains("result = 31 * result + Objects.hashCode(this.name.pattern)")
   }
 
+  @Test
+  fun `data class with ByteArray property has custom equals and hashCode methods`() {
+    val kotlinCode =
+      generateKotlinCode(
+        """
+      module my.mod
+
+      class Foo {
+        bytes: Bytes
+      }
+    """
+          .trimIndent()
+      )
+
+    assertThat(kotlinCode)
+      .contains("if (!this.bytes.contentEquals(other.bytes)) return false")
+      .contains("result = 31 * result + this.bytes.contentHashCode()")
+  }
+
   @Test
   fun `recursive types`() {
     val kotlinCode =
@@ -2078,6 +2099,7 @@ class KotlinCodeGeneratorTest {
         other,
         other,
         enumValue,
+        byteArrayOf(1, 2, 3, 4),
       )
 
     return other to propertyTypes

pkl-codegen-kotlin/src/test/resources/org/pkl/codegen/kotlin/PropertyTypes.kotlin

@@ -1,8 +1,10 @@
 package my
 
+import java.util.Arrays
 import java.util.Objects
 import kotlin.Any
 import kotlin.Boolean
+import kotlin.ByteArray
 import kotlin.Double
 import kotlin.Int
 import kotlin.Long
@@ -46,7 +48,8 @@ object Mod {
     open val regex: Regex,
     open val any: Any?,
     open val nonNull: Any,
-    open val enum: Direction
+    open val enum: Direction,
+    open val bytes: ByteArray
   ) {
     open fun copy(
       boolean: Boolean = this.boolean,
@@ -75,10 +78,11 @@ object Mod {
       regex: Regex = this.regex,
       any: Any? = this.any,
       nonNull: Any = this.nonNull,
-      enum: Direction = this.enum
+      enum: Direction = this.enum,
+      bytes: ByteArray = this.bytes
     ): PropertyTypes = PropertyTypes(boolean, int, float, string, duration, durationUnit, dataSize,
         dataSizeUnit, nullable, nullable2, pair, pair2, coll, coll2, list, list2, set, set2, map,
-        map2, container, container2, other, regex, any, nonNull, enum)
+        map2, container, container2, other, regex, any, nonNull, enum, bytes)
 
     override fun equals(other: Any?): Boolean {
       if (this === other) return true
@@ -111,6 +115,7 @@ object Mod {
       if (this.any != other.any) return false
       if (this.nonNull != other.nonNull) return false
       if (this.enum != other.enum) return false
+      if (!this.bytes.contentEquals(other.bytes)) return false
       return true
     }
 
@@ -143,11 +148,12 @@ object Mod {
       result = 31 * result + Objects.hashCode(this.any)
       result = 31 * result + Objects.hashCode(this.nonNull)
       result = 31 * result + Objects.hashCode(this.enum)
+      result = 31 * result + this.bytes.contentHashCode()
       return result
     }
 
     override fun toString(): String =
-        """PropertyTypes(boolean=$boolean, int=$int, float=$float, string=$string, duration=$duration, durationUnit=$durationUnit, dataSize=$dataSize, dataSizeUnit=$dataSizeUnit, nullable=$nullable, nullable2=$nullable2, pair=$pair, pair2=$pair2, coll=$coll, coll2=$coll2, list=$list, list2=$list2, set=$set, set2=$set2, map=$map, map2=$map2, container=$container, container2=$container2, other=$other, regex=$regex, any=$any, nonNull=$nonNull, enum=$enum)"""
+        """PropertyTypes(boolean=$boolean, int=$int, float=$float, string=$string, duration=$duration, durationUnit=$durationUnit, dataSize=$dataSize, dataSizeUnit=$dataSizeUnit, nullable=$nullable, nullable2=$nullable2, pair=$pair, pair2=$pair2, coll=$coll, coll2=$coll2, list=$list, list2=$list2, set=$set, set2=$set2, map=$map, map2=$map2, container=$container, container2=$container2, other=$other, regex=$regex, any=$any, nonNull=$nonNull, enum=$enum, bytes=${Arrays.toString(bytes)})"""
   }
 
   open class Other(

pkl-config-java/src/main/java/org/pkl/config/java/mapper/Conversions.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -291,7 +291,8 @@ public final class Conversions {
           Conversion.of(PClassInfo.Class, Object.class, Converter.identity()),
           Conversion.of(PClassInfo.Regex, Pattern.class, Converter.identity()),
           Conversion.of(PClassInfo.Regex, Object.class, Converter.identity()),
-          Conversion.of(PClassInfo.Null, PNull.class, Converter.identity())
+          Conversion.of(PClassInfo.Null, PNull.class, Converter.identity()),
+          Conversion.of(PClassInfo.Bytes, byte[].class, Converter.identity())
           // PClassInfo.Null -> Object.class is covered by PNullToAny (returns null rather than
           // PNull.getInstance())
           );

pkl-config-java/src/test/java/org/pkl/config/java/mapper/BytesToByteArrayTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.config.java.mapper;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.pkl.core.ModuleSource.modulePath;
+
+import org.junit.jupiter.api.Test;
+import org.pkl.core.Evaluator;
+import org.pkl.core.PModule;
+
+public class BytesToByteArrayTest {
+  private static final Evaluator evaluator = Evaluator.preconfigured();
+
+  private static final PModule module =
+      evaluator.evaluate(modulePath("org/pkl/config/java/mapper/BytesToByteArrayTest.pkl"));
+
+  private static final ValueMapper mapper = ValueMapperBuilder.preconfigured().build();
+
+  @Test
+  public void ex1() {
+    var ex1 = module.getProperty("ex1");
+    var mapped = mapper.map(ex1, Types.arrayOf(byte.class));
+    assertThat(mapped).isEqualTo(new byte[] {});
+  }
+
+  @Test
+  public void ex2() {
+    var ex2 = module.getProperty("ex2");
+    var mapped = mapper.map(ex2, Types.arrayOf(byte.class));
+    assertThat(mapped).isEqualTo(new byte[] {1, 2, 3, 4});
+  }
+}

pkl-config-java/src/test/resources/org/pkl/config/java/mapper/BytesToByteArrayTest.pkl

@@ -0,0 +1,2 @@
+ex1 = Bytes()
+ex2 = Bytes(1, 2, 3, 4)

pkl-core/src/main/java/org/pkl/core/Evaluator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,6 +53,15 @@ public interface Evaluator extends AutoCloseable {
    */
   String evaluateOutputText(ModuleSource moduleSource);
 
+  /**
+   * Evaluates a module's {@code output.bytes} property.
+   *
+   * @throws PklException if an error occurs during evaluation
+   * @throws IllegalStateException if this evaluator has already been closed
+   * @since 0.29.0
+   */
+  byte[] evaluateOutputBytes(ModuleSource moduleSource);
+
   /**
    * Evaluates a module's {@code output.value} property.
    *
@@ -143,6 +152,10 @@ public interface Evaluator extends AutoCloseable {
    *       <td>TypeAlias</td>
    *       <td>{@link TypeAlias}</td>
    *     </tr>
+   *     <tr>
+   *       <td>Bytes</td>
+   *       <td>{@code byte[]}</td>
+   *     </tr>
    *   </tbody>
    * </table>
    *

pkl-core/src/main/java/org/pkl/core/EvaluatorImpl.java

@@ -144,6 +144,16 @@ public class EvaluatorImpl implements Evaluator {
         });
   }
 
+  public byte[] evaluateOutputBytes(ModuleSource moduleSource) {
+    return doEvaluate(
+        moduleSource,
+        (module) -> {
+          var output = readModuleOutput(module);
+          var vmBytes = VmUtils.readBytesProperty(output);
+          return vmBytes.export();
+        });
+  }
+
   @Override
   public Object evaluateOutputValue(ModuleSource moduleSource) {
     return doEvaluate(
@@ -183,32 +193,31 @@ public class EvaluatorImpl implements Evaluator {
 
   @Override
   public Object evaluateExpression(ModuleSource moduleSource, String expression) {
-    // optimization: if the expression is `output.text` or `output.value` (the common cases), read
+    // optimization: if the expression is `output.text`, `output.value` or `output.bytes` (the
-    // members directly instead of creating new truffle nodes.
+    // common cases), read members directly instead of creating new truffle nodes.
-    if (expression.equals("output.text")) {
+    return switch (expression) {
-      return evaluateOutputText(moduleSource);
+      case "output.text" -> evaluateOutputText(moduleSource);
-    }
+      case "output.value" -> evaluateOutputValue(moduleSource);
-    if (expression.equals("output.value")) {
+      case "output.bytes" -> evaluateOutputBytes(moduleSource);
-      return evaluateOutputValue(moduleSource);
+      default ->
-    }
+          doEvaluate(
-    return doEvaluate(
+              moduleSource,
-        moduleSource,
+              (module) -> {
-        (module) -> {
+                var expressionResult =
-          var expressionResult =
+                    VmUtils.evaluateExpression(module, expression, securityManager, moduleResolver);
-              VmUtils.evaluateExpression(module, expression, securityManager, moduleResolver);
+                if (expressionResult instanceof VmValue value) {
-          if (expressionResult instanceof VmValue value) {
+                  value.force(false);
-            value.force(false);
+                  return value.export();
-            return value.export();
+                }
-          }
+                return expressionResult;
-          return expressionResult;
+              });
-        });
+    };
   }
 
   @Override
   public String evaluateExpressionString(ModuleSource moduleSource, String expression) {
     // optimization: if the expression is `output.text` (the common case), read members
-    // directly
+    // directly instead of creating new truffle nodes.
-    // instead of creating new truffle nodes.
     if (expression.equals("output.text")) {
       return evaluateOutputText(moduleSource);
     }
@@ -280,6 +289,10 @@ public class EvaluatorImpl implements Evaluator {
     return doEvaluate(() -> VmUtils.readTextProperty(fileOutput));
   }
 
+  byte[] evaluateOutputBytes(VmTyped fileOutput) {
+    return doEvaluate(() -> VmUtils.readBytesProperty(fileOutput).export());
+  }
+
   private <T> T doEvaluate(Supplier<T> supplier) {
     @Nullable TimeoutTask timeoutTask = null;
     logger.clear();

pkl-core/src/main/java/org/pkl/core/FileOutput.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,14 @@ public interface FileOutput {
   /**
    * Returns the text content of this file.
    *
-   * @throws PklException if an error occurs during evaluation
+   * @throws PklException if an error occurs during evaluation.
    */
   String getText();
+
+  /**
+   * Returns the byte contents of this file.
+   *
+   * @throws PklException if an error occurs during evaluation.
+   */
+  byte[] getBytes();
 }

pkl-core/src/main/java/org/pkl/core/FileOutputImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,4 +44,16 @@ final class FileOutputImpl implements FileOutput {
       throw new PklBugException(e);
     }
   }
+
+  @Override
+  public byte[] getBytes() {
+    try {
+      return evaluator.evaluateOutputBytes(fileOutput);
+    } catch (PolyglotException e) {
+      if (e.isCancelled()) {
+        throw new PklException("The evaluator is no longer available", e);
+      }
+      throw new PklBugException(e);
+    }
+  }
 }

pkl-core/src/main/java/org/pkl/core/JsonRenderer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -102,6 +102,12 @@ final class JsonRenderer implements ValueRenderer {
           String.format("Values of type `DataSize` cannot be rendered as JSON. Value: %s", value));
     }
 
+    @Override
+    public void visitBytes(byte[] value) {
+      throw new RendererException(
+          String.format("Values of type `Bytes` cannot be rendered as JSON. Value: %s", value));
+    }
+
     @Override
     public void visitPair(Pair<?, ?> value) {
       try {

pkl-core/src/main/java/org/pkl/core/PClassInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,6 +49,7 @@ public final class PClassInfo<T> implements Serializable {
   public static final PClassInfo<Double> Float = pklBaseClassInfo("Float", double.class);
   public static final PClassInfo<Duration> Duration = pklBaseClassInfo("Duration", Duration.class);
   public static final PClassInfo<DataSize> DataSize = pklBaseClassInfo("DataSize", DataSize.class);
+  public static final PClassInfo<byte[]> Bytes = pklBaseClassInfo("Bytes", byte[].class);
   public static final PClassInfo<Pair> Pair = pklBaseClassInfo("Pair", Pair.class);
   public static final PClassInfo<Void> Collection = pklBaseClassInfo("Collection", Void.class);
   public static final PClassInfo<ArrayList> List = pklBaseClassInfo("List", ArrayList.class);
@@ -115,6 +116,7 @@ public final class PClassInfo<T> implements Serializable {
     if (value instanceof Set) return (PClassInfo<T>) Set;
     if (value instanceof Map) return (PClassInfo<T>) Map;
     if (value instanceof Pattern) return (PClassInfo<T>) Regex;
+    if (value instanceof byte[]) return (PClassInfo<T>) Bytes;
 
     throw new IllegalArgumentException("Not a Pkl value: " + value);
   }

pkl-core/src/main/java/org/pkl/core/PListRenderer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.io.Writer;
 import java.util.*;
 import java.util.regex.Pattern;
 import org.pkl.core.util.ArrayCharEscaper;
+import org.pkl.core.util.ByteArrayUtils;
 
 // To instantiate this class, use ValueRenderers.plist().
 final class PListRenderer implements ValueRenderer {
@@ -136,6 +137,13 @@ final class PListRenderer implements ValueRenderer {
               value));
     }
 
+    @Override
+    public void visitBytes(byte[] value) {
+      write("<data>");
+      write(ByteArrayUtils.base64(value));
+      write("</data>");
+    }
+
     @Override
     public void visitPair(Pair<?, ?> value) {
       doVisitIterable(value, false);

pkl-core/src/main/java/org/pkl/core/PcfRenderer.java

@@ -92,6 +92,21 @@ final class PcfRenderer implements ValueRenderer {
       write(value.toString());
     }
 
+    @Override
+    public void visitBytes(byte[] value) {
+      write("Bytes(\"");
+      var isFirst = true;
+      for (var byt : value) {
+        if (isFirst) {
+          isFirst = false;
+        } else {
+          write(", ");
+        }
+        write(Integer.valueOf(Byte.toUnsignedInt(byt)).toString());
+      }
+      write(")");
+    }
+
     @Override
     public void visitPair(Pair<?, ?> value) {
       doVisitIterable(value, "Pair(");

pkl-core/src/main/java/org/pkl/core/PropertiesRenderer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -106,6 +106,13 @@ final class PropertiesRenderer implements ValueRenderer {
               "Values of type `DataSize` cannot be rendered as Properties. Value: %s", value));
     }
 
+    @Override
+    public String convertBytes(byte[] value) {
+      throw new RendererException(
+          String.format(
+              "Values of type `Bytes` cannot be rendered as Properties. Value: %s", value));
+    }
+
     @Override
     public String convertPair(Pair<?, ?> value) {
       throw new RendererException(

pkl-core/src/main/java/org/pkl/core/ValueConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -37,6 +37,8 @@ public interface ValueConverter<T> {
 
   T convertDataSize(DataSize value);
 
+  T convertBytes(byte[] value);
+
   T convertPair(Pair<?, ?> value);
 
   T convertList(List<?> value);

pkl-core/src/main/java/org/pkl/core/ValueVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,6 +53,10 @@ public interface ValueVisitor {
     visitDefault(value);
   }
 
+  default void visitBytes(byte[] value) {
+    visitDefault(value);
+  }
+
   default void visitPair(Pair<?, ?> value) {
     visitDefault(value);
   }
@@ -108,6 +112,8 @@ public interface ValueVisitor {
       visitMap(map);
     } else if (value instanceof Pattern pattern) {
       visitRegex(pattern);
+    } else if (value instanceof byte[] bytes) {
+      visitBytes(bytes);
     } else {
       throw new IllegalArgumentException("Cannot visit value with unexpected type: " + value);
     }

pkl-core/src/main/java/org/pkl/core/YamlRenderer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -151,6 +151,12 @@ final class YamlRenderer implements ValueRenderer {
           String.format("Values of type `DataSize` cannot be rendered as YAML. Value: %s", value));
     }
 
+    @Override
+    public void visitBytes(byte[] value) {
+      throw new RendererException(
+          String.format("Values of type `Bytes` cannot be rendered as YAML. Value: %s", value));
+    }
+
     @Override
     public void visitPair(Pair<?, ?> value) {
       doVisitIterable(value, null);

pkl-core/src/main/java/org/pkl/core/ast/ByteConstantValueNode.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.core.ast;
+
+import com.oracle.truffle.api.frame.VirtualFrame;
+
+public class ByteConstantValueNode extends ExpressionNode implements ConstantNode {
+
+  private final byte value;
+
+  public ByteConstantValueNode(byte value) {
+    this.value = value;
+  }
+
+  @Override
+  public Long getValue() {
+    return (long) value;
+  }
+
+  public byte getByteValue() {
+    return value;
+  }
+
+  @Override
+  public Object executeGeneric(VirtualFrame frame) {
+    return getValue();
+  }
+}

pkl-core/src/main/java/org/pkl/core/ast/builder/AstBuilder.java

@@ -29,6 +29,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.BiFunction;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import org.graalvm.collections.EconomicMap;
@@ -37,6 +38,7 @@ import org.pkl.core.PklBugException;
 import org.pkl.core.SecurityManagerException;
 import org.pkl.core.TypeParameter;
 import org.pkl.core.TypeParameter.Variance;
+import org.pkl.core.ast.ByteConstantValueNode;
 import org.pkl.core.ast.ConstantNode;
 import org.pkl.core.ast.ConstantValueNode;
 import org.pkl.core.ast.ExpressionNode;
@@ -77,6 +79,7 @@ import org.pkl.core.ast.expression.generator.GeneratorSpreadNodeGen;
 import org.pkl.core.ast.expression.generator.GeneratorWhenNode;
 import org.pkl.core.ast.expression.generator.RestoreForBindingsNode;
 import org.pkl.core.ast.expression.literal.AmendModuleNodeGen;
+import org.pkl.core.ast.expression.literal.BytesLiteralNode;
 import org.pkl.core.ast.expression.literal.CheckIsAnnotationClassNode;
 import org.pkl.core.ast.expression.literal.ConstantEntriesLiteralNodeGen;
 import org.pkl.core.ast.expression.literal.ElementsEntriesLiteralNodeGen;
@@ -160,6 +163,7 @@ import org.pkl.core.packages.PackageLoadError;
 import org.pkl.core.runtime.BaseModule;
 import org.pkl.core.runtime.ModuleInfo;
 import org.pkl.core.runtime.ModuleResolver;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmClass;
 import org.pkl.core.runtime.VmContext;
 import org.pkl.core.runtime.VmDataSize;
@@ -524,9 +528,7 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
     }
   }
 
-  @Override
+  private <T> T parseNumber(IntLiteralExpr expr, BiFunction<String, Integer, T> parser) {
-  public IntLiteralNode visitIntLiteralExpr(IntLiteralExpr expr) {
-    var section = createSourceSection(expr);
     var text = remove_(expr.getNumber());
 
     var radix = 10;
@@ -547,11 +549,17 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
       // also moves negation from runtime to parse time
       text = "-" + text;
     }
+    return parser.apply(text, radix);
+  }
 
+  @Override
+  public IntLiteralNode visitIntLiteralExpr(IntLiteralExpr expr) {
+    var section = createSourceSection(expr);
     try {
-      var num = Long.parseLong(text, radix);
+      var num = parseNumber(expr, Long::parseLong);
       return new IntLiteralNode(section, num);
     } catch (NumberFormatException e) {
+      var text = expr.getNumber();
       throw exceptionBuilder().evalError("intTooLarge", text).withSourceSection(section).build();
     }
   }
@@ -637,8 +645,8 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
     }
 
     // TODO: make sure that no user-defined List/Set/Map method is in scope
-    // TODO: support qualified calls (e.g., `import "pkl:base"; x = base.List()/Set()/Map()`) for
+    // TODO: support qualified calls (e.g., `import "pkl:base"; x =
-    // correctness
+    // base.List()/Set()/Map()/Bytes()`) for correctness
     if (identifier == org.pkl.core.runtime.Identifier.LIST) {
       return doVisitListLiteral(expr, argList);
     }
@@ -651,6 +659,10 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
       return doVisitMapLiteral(expr, argList);
     }
 
+    if (identifier == org.pkl.core.runtime.Identifier.BYTES_CONSTRUCTOR) {
+      return doVisitBytesLiteral(expr, argList);
+    }
+
     var scope = symbolTable.getCurrentScope();
 
     return new ResolveMethodNode(
@@ -1083,6 +1095,18 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
         : new MapLiteralNode(createSourceSection(expr), keyAndValueNodes.first);
   }
 
+  private ExpressionNode doVisitBytesLiteral(Expr expr, ArgumentList argList) {
+    var elementNodes = createCollectionArgumentBytesNodes(argList);
+
+    if (elementNodes.first.length == 0) {
+      return new ConstantValueNode(VmBytes.EMPTY);
+    }
+    return elementNodes.second
+        ? new ConstantValueNode(
+            createSourceSection(expr), VmBytes.createFromConstantNodes(elementNodes.first))
+        : new BytesLiteralNode(createSourceSection(expr), elementNodes.first);
+  }
+
   private Pair<ExpressionNode[], Boolean> createCollectionArgumentNodes(ArgumentList exprs) {
     var args = exprs.getArguments();
     var elementNodes = new ExpressionNode[args.size()];
@@ -1097,6 +1121,32 @@ public class AstBuilder extends AbstractAstBuilder<Object> {
     return Pair.of(elementNodes, isConstantNodes);
   }
 
+  private Pair<ExpressionNode[], Boolean> createCollectionArgumentBytesNodes(ArgumentList exprs) {
+    var args = exprs.getArguments();
+    var expressionNodes = new ExpressionNode[args.size()];
+    var isAllByteLiterals = true;
+
+    for (var i = 0; i < args.size(); i++) {
+      var expr = args.get(i);
+      if (expr instanceof IntLiteralExpr intLiteralExpr && isAllByteLiterals) {
+        try {
+          var byt = parseNumber(intLiteralExpr, Byte::parseByte);
+          expressionNodes[i] = new ByteConstantValueNode(byt);
+        } catch (NumberFormatException e) {
+          // proceed with initializing a constant value node; we'll throw an error inside
+          // BytesLiteralNode.
+          isAllByteLiterals = false;
+          expressionNodes[i] = visitExpr(expr);
+        }
+      } else {
+        isAllByteLiterals = false;
+        expressionNodes[i] = visitExpr(expr);
+      }
+    }
+
+    return Pair.of(expressionNodes, isAllByteLiterals);
+  }
+
   public GeneratorMemberNode visitObjectMember(org.pkl.parser.syntax.ObjectMember member) {
     return (GeneratorMemberNode) member.accept(this);
   }

pkl-core/src/main/java/org/pkl/core/ast/expression/binary/AdditionNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -78,4 +78,9 @@ public abstract class AdditionNode extends BinaryExpressionNode {
   protected VmMap eval(VmMap left, VmMap right) {
     return left.concatenate(right);
   }
+
+  @Specialization
+  protected VmBytes eval(VmBytes left, VmBytes right) {
+    return left.concatenate(right);
+  }
 }

pkl-core/src/main/java/org/pkl/core/ast/expression/binary/SubscriptNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -98,6 +98,18 @@ public abstract class SubscriptNode extends BinaryExpressionNode {
     return readMember(dynamic, key, callNode);
   }
 
+  @Specialization
+  protected long eval(VmBytes receiver, long index) {
+    if (index < 0 || index >= receiver.getLength()) {
+      CompilerDirectives.transferToInterpreter();
+      throw exceptionBuilder()
+          .evalError("elementIndexOutOfRange", index, 0, receiver.getLength() - 1)
+          .withProgramValue("Value", receiver)
+          .build();
+    }
+    return receiver.get(index);
+  }
+
   private Object readMember(VmObject object, Object key, IndirectCallNode callNode) {
     var result = VmUtils.readMemberOrNull(object, key, callNode);
     if (result != null) return result;

pkl-core/src/main/java/org/pkl/core/ast/expression/generator/GeneratorForNode.java

@@ -118,6 +118,14 @@ public abstract class GeneratorForNode extends GeneratorMemberNode {
     }
   }
 
+  @Specialization
+  protected void eval(VirtualFrame frame, Object parent, ObjectData data, VmBytes iterable) {
+    long idx = 0;
+    for (var byt : iterable.getBytes()) {
+      executeIteration(frame, parent, data, idx++, (long) byt);
+    }
+  }
+
   @Fallback
   @SuppressWarnings("unused")
   protected void fallback(VirtualFrame frame, Object parent, ObjectData data, Object iterable) {

pkl-core/src/main/java/org/pkl/core/ast/expression/generator/GeneratorSpreadNode.java

@@ -29,6 +29,7 @@ import org.pkl.core.ast.member.ObjectMember;
 import org.pkl.core.runtime.BaseModule;
 import org.pkl.core.runtime.Identifier;
 import org.pkl.core.runtime.Iterators.TruffleIterator;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmClass;
 import org.pkl.core.runtime.VmCollection;
 import org.pkl.core.runtime.VmDynamic;
@@ -161,6 +162,16 @@ public abstract class GeneratorSpreadNode extends GeneratorMemberNode {
     doEvalIntSeq(frame, parent, data, iterable);
   }
 
+  @Specialization
+  protected void eval(VirtualFrame frame, VmObject parent, ObjectData data, VmBytes iterable) {
+    doEvalBytes(frame, parent.getVmClass(), data, iterable);
+  }
+
+  @Specialization
+  protected void eval(VirtualFrame frame, VmClass parent, ObjectData data, VmBytes iterable) {
+    doEvalBytes(frame, parent, data, iterable);
+  }
+
   @Fallback
   @SuppressWarnings("unused")
   protected void fallback(VirtualFrame frame, Object parent, ObjectData data, Object iterable) {
@@ -266,6 +277,18 @@ public abstract class GeneratorSpreadNode extends GeneratorMemberNode {
     spreadIterable(frame, data, iterable);
   }
 
+  private void doEvalBytes(VirtualFrame frame, VmClass parent, ObjectData data, VmBytes iterable) {
+    if (isTypedObjectClass(parent) || parent == getMappingClass()) {
+      CompilerDirectives.transferToInterpreter();
+      throw exceptionBuilder()
+          .evalError("cannotSpreadObject", iterable.getVmClass(), parent)
+          .withHint("`Bytes` can only be spread into objects of type `Dynamic` and `Listing`.")
+          .withProgramValue("Value", iterable)
+          .build();
+    }
+    spreadIterable(frame, data, iterable);
+  }
+
   private void cannotHaveMember(VmClass clazz, ObjectMember member) {
     CompilerDirectives.transferToInterpreter();
     var builder = exceptionBuilder();

pkl-core/src/main/java/org/pkl/core/ast/expression/literal/BytesLiteralNode.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.core.ast.expression.literal;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.nodes.ExplodeLoop;
+import com.oracle.truffle.api.nodes.NodeInfo;
+import com.oracle.truffle.api.source.SourceSection;
+import org.pkl.core.ast.ExpressionNode;
+import org.pkl.core.ast.type.TypeNode;
+import org.pkl.core.ast.type.TypeNode.UInt8TypeAliasTypeNode;
+import org.pkl.core.ast.type.VmTypeMismatchException;
+import org.pkl.core.runtime.VmBytes;
+import org.pkl.core.runtime.VmUtils;
+import org.pkl.core.util.LateInit;
+
+@NodeInfo(shortName = "Bytes()")
+public final class BytesLiteralNode extends ExpressionNode {
+  @Children private final ExpressionNode[] elements;
+
+  @Child @LateInit private TypeNode typeNode;
+
+  public BytesLiteralNode(SourceSection sourceSection, ExpressionNode[] elements) {
+    super(sourceSection);
+    this.elements = elements;
+  }
+
+  private TypeNode getTypeNode() {
+    if (typeNode == null) {
+      CompilerDirectives.transferToInterpreterAndInvalidate();
+      typeNode = new UInt8TypeAliasTypeNode();
+    }
+    return typeNode;
+  }
+
+  @Override
+  @ExplodeLoop
+  public Object executeGeneric(VirtualFrame frame) {
+    var bytes = new byte[elements.length];
+    var typeNode = getTypeNode();
+    for (var i = 0; i < elements.length; i++) {
+      var elem = elements[i];
+      try {
+        var result = (Long) typeNode.execute(frame, elem.executeGeneric(frame));
+        bytes[i] = result.byteValue();
+      } catch (VmTypeMismatchException err) {
+        // optimization: don't create a new stack frame to check the type, but pretend that one
+        // exists.
+        err.putInsertedStackFrame(
+            getRootNode().getCallTarget(),
+            VmUtils.createStackFrame(elem.getSourceSection(), getRootNode().getName()));
+        throw err.toVmException();
+      }
+    }
+    return new VmBytes(bytes);
+  }
+}

pkl-core/src/main/java/org/pkl/core/ast/type/TypeNode.java

@@ -2153,52 +2153,71 @@ public abstract class TypeNode extends PklNode {
     }
   }
 
-  public static final class UIntTypeAliasTypeNode extends IntSlotTypeNode {
+  protected abstract static class IntMaskSlotTypeNode extends IntSlotTypeNode {
-    private final VmTypeAlias typeAlias;
+    protected final long mask;
-    private final long mask;
-
-    public UIntTypeAliasTypeNode(VmTypeAlias typeAlias, long mask) {
 
+    IntMaskSlotTypeNode(long mask) {
       super(VmUtils.unavailableSourceSection());
-      this.typeAlias = typeAlias;
       this.mask = mask;
     }
 
     @Override
-    protected Object executeLazily(VirtualFrame frame, Object value) {
+    protected final Object executeLazily(VirtualFrame frame, Object value) {
+      var typealias = getVmTypeAlias();
+      assert typealias != null;
       if (value instanceof Long l) {
         if ((l & mask) == l) return value;
 
-        throw new VmTypeMismatchException.Constraint(typeAlias.getConstraintSection(), value);
+        throw new VmTypeMismatchException.Constraint(typealias.getConstraintSection(), value);
       }
 
       throw new VmTypeMismatchException.Simple(
-          typeAlias.getBaseTypeSection(), value, BaseModule.getIntClass());
+          typealias.getBaseTypeSection(), value, BaseModule.getIntClass());
     }
 
     @Override
-    public VmClass getVmClass() {
+    public final VmClass getVmClass() {
       return BaseModule.getIntClass();
     }
 
+    @Override
+    public final VmTyped getMirror() {
+      return MirrorFactories.typeAliasTypeFactory.create(this);
+    }
+
+    @Override
+    public final boolean doIsEquivalentTo(TypeNode other) {
+      return other instanceof UIntTypeAliasTypeNode aliasTypeNode && mask == aliasTypeNode.mask;
+    }
+
+    @Override
+    protected final boolean acceptTypeNode(TypeNodeConsumer consumer) {
+      return consumer.accept(this);
+    }
+  }
+
+  public static final class UIntTypeAliasTypeNode extends IntMaskSlotTypeNode {
+    private final VmTypeAlias typeAlias;
+
+    public UIntTypeAliasTypeNode(VmTypeAlias typeAlias, long mask) {
+      super(mask);
+      this.typeAlias = typeAlias;
+    }
+
     @Override
     public VmTypeAlias getVmTypeAlias() {
       return typeAlias;
     }
+  }
 
-    @Override
+  public static final class UInt8TypeAliasTypeNode extends IntMaskSlotTypeNode {
-    public VmTyped getMirror() {
+    public UInt8TypeAliasTypeNode() {
-      return MirrorFactories.typeAliasTypeFactory.create(this);
+      super(0x00000000000000FFL);
     }
 
     @Override
-    public boolean doIsEquivalentTo(TypeNode other) {
+    public VmTypeAlias getVmTypeAlias() {
-      return other instanceof UIntTypeAliasTypeNode aliasTypeNode && mask == aliasTypeNode.mask;
+      return BaseModule.getUInt8TypeAlias();
-    }
-
-    @Override
-    protected boolean acceptTypeNode(TypeNodeConsumer consumer) {
-      return consumer.accept(this);
     }
   }
 

pkl-core/src/main/java/org/pkl/core/ast/type/UnresolvedTypeNode.java

@@ -174,7 +174,7 @@ public abstract class UnresolvedTypeNode extends PklNode {
             case "Int8":
               return new Int8TypeAliasTypeNode();
             case "UInt8":
-              return new UIntTypeAliasTypeNode(alias, 0x00000000000000FFL);
+              return new UInt8TypeAliasTypeNode();
             case "Int16":
               return new Int16TypeAliasTypeNode();
             case "UInt16":

pkl-core/src/main/java/org/pkl/core/resource/Resource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@ package org.pkl.core.resource;
 
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
-import java.util.Base64;
+import org.pkl.core.util.ByteArrayUtils;
 
 /** An external (file, HTTP, etc.) resource. */
 public record Resource(URI uri, byte[] bytes) {
@@ -44,6 +44,6 @@ public record Resource(URI uri, byte[] bytes) {
 
   /** Returns the content of this resource in Base64. */
   public String getBase64() {
-    return Base64.getEncoder().encodeToString(bytes);
+    return ByteArrayUtils.base64(bytes);
   }
 }

pkl-core/src/main/java/org/pkl/core/runtime/BaseModule.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -71,6 +71,10 @@ public final class BaseModule extends StdLibModule {
     return DataSizeClass.instance;
   }
 
+  public static VmClass getBytesClass() {
+    return BytesClass.instance;
+  }
+
   public static VmClass getIntSeqClass() {
     return IntSeqClass.instance;
   }
@@ -219,6 +223,10 @@ public final class BaseModule extends StdLibModule {
     return MixinTypeAlias.instance;
   }
 
+  public static VmTypeAlias getUInt8TypeAlias() {
+    return UInt8TypeAlias.instance;
+  }
+
   private static final class AnyClass {
     static final VmClass instance = loadClass("Any");
   }
@@ -259,6 +267,10 @@ public final class BaseModule extends StdLibModule {
     static final VmClass instance = loadClass("DataSize");
   }
 
+  private static final class BytesClass {
+    static final VmClass instance = loadClass("Bytes");
+  }
+
   private static final class IntSeqClass {
     static final VmClass instance = loadClass("IntSeq");
   }
@@ -383,6 +395,10 @@ public final class BaseModule extends StdLibModule {
     static final VmTypeAlias instance = loadTypeAlias("Int32");
   }
 
+  private static final class UInt8TypeAlias {
+    static final VmTypeAlias instance = loadTypeAlias("UInt8");
+  }
+
   private static final class MixinTypeAlias {
     static final VmTypeAlias instance = loadTypeAlias("Mixin");
   }

pkl-core/src/main/java/org/pkl/core/runtime/Identifier.java

@@ -75,6 +75,11 @@ public final class Identifier implements Comparable<Identifier> {
   // XmlCData}
   public static final Identifier TEXT = get("text");
 
+  public static final Identifier BYTES_CONSTRUCTOR = get("Bytes");
+
+  // members of pkl.base#{FileOutput}
+  public static final Identifier BYTES = get("bytes");
+
   // members of pkl.base#ModuleOutput, pkl.base#Resource, pkl.base#String
   public static final Identifier BASE64 = get("base64");
 

pkl-core/src/main/java/org/pkl/core/runtime/ResourceManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,7 +53,7 @@ public final class ResourceManager {
         new VmObjectFactory<Resource>(BaseModule::getResourceClass)
             .addProperty("uri", resource -> resource.uri().toString())
             .addProperty("text", Resource::getText)
-            .addProperty("base64", Resource::getBase64);
+            .addProperty("bytes", resource -> new VmBytes(resource.bytes()));
   }
 
   @TruffleBoundary

pkl-core/src/main/java/org/pkl/core/runtime/VmBytes.java

@@ -0,0 +1,208 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.core.runtime;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+import com.oracle.truffle.api.CompilerDirectives.ValueType;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.PrimitiveIterator;
+import org.pkl.core.DataSizeUnit;
+import org.pkl.core.ast.ByteConstantValueNode;
+import org.pkl.core.ast.ExpressionNode;
+import org.pkl.core.util.ByteArrayUtils;
+import org.pkl.core.util.Nullable;
+
+@ValueType
+public final class VmBytes extends VmValue implements Iterable<Long> {
+
+  private @Nullable VmList vmList;
+  private @Nullable String base64;
+  private @Nullable String hex;
+  private final byte[] bytes;
+  private @Nullable VmDataSize size;
+
+  public static VmBytes EMPTY = new VmBytes(new byte[0]);
+
+  @TruffleBoundary
+  public static VmBytes createFromConstantNodes(ExpressionNode[] elements) {
+    if (elements.length == 0) {
+      return EMPTY;
+    }
+    var bytes = new byte[elements.length];
+    for (var i = 0; i < elements.length; i++) {
+      var exprNode = elements[i];
+      // guaranteed by AstBuilder
+      assert exprNode instanceof ByteConstantValueNode;
+      bytes[i] = ((ByteConstantValueNode) exprNode).getByteValue();
+    }
+    return new VmBytes(bytes);
+  }
+
+  public VmBytes(byte[] bytes) {
+    this.bytes = bytes;
+  }
+
+  public VmBytes(VmList vmList, byte[] bytes) {
+    this.vmList = vmList;
+    this.bytes = bytes;
+  }
+
+  @Override
+  public VmClass getVmClass() {
+    return BaseModule.getBytesClass();
+  }
+
+  @Override
+  public void force(boolean allowUndefinedValues) {
+    // do nothing
+  }
+
+  @Override
+  public byte[] export() {
+    return bytes;
+  }
+
+  @Override
+  public void accept(VmValueVisitor visitor) {
+    visitor.visitBytes(this);
+  }
+
+  @Override
+  public <T> T accept(VmValueConverter<T> converter, Iterable<Object> path) {
+    return converter.convertBytes(this, path);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (!(obj instanceof VmBytes vmBytes)) {
+      return false;
+    }
+    return Arrays.equals(bytes, vmBytes.bytes);
+  }
+
+  @Override
+  public int hashCode() {
+    return Arrays.hashCode(bytes);
+  }
+
+  public byte[] getBytes() {
+    return bytes;
+  }
+
+  public long get(long index) {
+    return getBytes()[(int) index];
+  }
+
+  public VmBytes concatenate(VmBytes right) {
+    if (bytes.length == 0) return right;
+    if (right.bytes.length == 0) return this;
+
+    var newBytes = new byte[bytes.length + right.bytes.length];
+    System.arraycopy(bytes, 0, newBytes, 0, bytes.length);
+    System.arraycopy(right.bytes, 0, newBytes, bytes.length, right.bytes.length);
+    return new VmBytes(newBytes);
+  }
+
+  public VmList toList() {
+    if (vmList == null) {
+      vmList = VmList.create(bytes);
+    }
+    return vmList;
+  }
+
+  public String base64() {
+    if (base64 == null) {
+      base64 = ByteArrayUtils.base64(bytes);
+    }
+    return base64;
+  }
+
+  public String hex() {
+    if (hex == null) {
+      hex = ByteArrayUtils.toHex(bytes);
+    }
+    return hex;
+  }
+
+  public int getLength() {
+    return bytes.length;
+  }
+
+  public VmDataSize getSize() {
+    if (size == null) {
+      if (getLength() == 0) {
+        // avoid log10(0), which gives us -Infinity
+        size = new VmDataSize(0, DataSizeUnit.BYTES);
+      } else {
+        var magnitude = (int) Math.floor(Math.log10(getLength()));
+        var unit =
+            switch (magnitude) {
+              case 0, 1, 2 -> DataSizeUnit.BYTES;
+              case 3, 4, 5 -> DataSizeUnit.KILOBYTES;
+              case 6, 7, 8 -> DataSizeUnit.MEGABYTES;
+              case 9, 10, 11 -> DataSizeUnit.GIGABYTES;
+              // in practice, can never happen (Java can only hold at most math.maxInt bytes).
+              case 12, 13, 14 -> DataSizeUnit.TERABYTES;
+              default -> DataSizeUnit.PETABYTES;
+            };
+        size = new VmDataSize(getLength(), DataSizeUnit.BYTES).convertTo(unit);
+      }
+    }
+    return size;
+  }
+
+  @Override
+  public String toString() {
+    var sb = new StringBuilder("Bytes(");
+    var isFirst = true;
+    for (var byt : bytes) {
+      if (isFirst) {
+        isFirst = false;
+      } else {
+        sb.append(", ");
+      }
+      sb.append(Byte.toUnsignedInt(byt));
+    }
+    sb.append(")");
+    return sb.toString();
+  }
+
+  @Override
+  public Iterator<Long> iterator() {
+    return new PrimitiveIterator.OfLong() {
+      int index = 0;
+
+      @Override
+      public boolean hasNext() {
+        return index < bytes.length;
+      }
+
+      @Override
+      public long nextLong() {
+        if (!hasNext()) {
+          CompilerDirectives.transferToInterpreter();
+          throw new NoSuchElementException();
+        }
+        var result = Byte.toUnsignedLong(bytes[index]);
+        index += 1;
+        return result;
+      }
+    };
+  }
+}

pkl-core/src/main/java/org/pkl/core/runtime/VmList.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -98,6 +98,16 @@ public final class VmList extends VmCollection {
     return new VmList(vector.immutable());
   }
 
+  @TruffleBoundary
+  public static VmList create(byte[] elements) {
+    if (elements.length == 0) return EMPTY;
+    var vector = RrbTree.emptyMutable();
+    for (var elem : elements) {
+      vector.append(Byte.toUnsignedLong(elem));
+    }
+    return new VmList(vector.immutable());
+  }
+
   @TruffleBoundary
   public static VmList create(Object[] elements, int length) {
     if (elements.length == 0) return EMPTY;

pkl-core/src/main/java/org/pkl/core/runtime/VmUtils.java

@@ -175,6 +175,10 @@ public final class VmUtils {
     return (String) VmUtils.readMember((VmObjectLike) receiver, Identifier.TEXT);
   }
 
+  public static VmBytes readBytesProperty(VmObjectLike receiver) {
+    return (VmBytes) VmUtils.readMember(receiver, Identifier.BYTES);
+  }
+
   @TruffleBoundary
   public static Object readMember(VmObjectLike receiver, Object memberKey) {
     var result = readMemberOrNull(receiver, memberKey);

pkl-core/src/main/java/org/pkl/core/runtime/VmValueConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,6 +52,8 @@ public interface VmValueConverter<T> {
 
   T convertDataSize(VmDataSize value, Iterable<Object> path);
 
+  T convertBytes(VmBytes vmBytes, Iterable<Object> path);
+
   T convertIntSeq(VmIntSeq value, Iterable<Object> path);
 
   T convertList(VmList value, Iterable<Object> path);

pkl-core/src/main/java/org/pkl/core/runtime/VmValueRenderer.java

@@ -114,6 +114,45 @@ public final class VmValueRenderer {
       append(value);
     }
 
+    private void renderByteSize(VmDataSize size) {
+      var value = size.getValue();
+      if (value % 1 == 0) {
+        append((int) value);
+      } else if ((value * 10) % 1 == 0) {
+        append(String.format("%.1f", value));
+      } else {
+        append(String.format("%.2f", value));
+      }
+      append(".");
+      append(size.getUnit());
+    }
+
+    @Override
+    public void visitBytes(VmBytes value) {
+      append("Bytes(");
+      // truncate bytes if over 8 bytes
+      renderByteElems(value, Math.min(value.getLength(), 8));
+      if (value.getLength() > 8) {
+        append(", ... <total size: ");
+        renderByteSize(value.getSize());
+        append(">");
+      }
+      append(")");
+    }
+
+    private void renderByteElems(VmBytes value, int limit) {
+      var isFirst = true;
+      var bytes = value.getBytes();
+      for (var i = 0; i < limit; i++) {
+        if (isFirst) {
+          isFirst = false;
+        } else {
+          append(", ");
+        }
+        append(Byte.toUnsignedInt(bytes[i]));
+      }
+    }
+
     @Override
     public void visitPair(VmPair value) {
       append("Pair(");

pkl-core/src/main/java/org/pkl/core/runtime/VmValueVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,8 @@ public interface VmValueVisitor {
 
   void visitDataSize(VmDataSize value);
 
+  void visitBytes(VmBytes value);
+
   void visitIntSeq(VmIntSeq value);
 
   void visitList(VmList value);

pkl-core/src/main/java/org/pkl/core/stdlib/PklConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,7 @@ public final class PklConverter implements VmValueConverter<Object> {
   private final @Nullable VmFunction floatConverter;
   private final @Nullable VmFunction durationConverter;
   private final @Nullable VmFunction dataSizeConverter;
+  private final @Nullable VmFunction bytesConverter;
   private final @Nullable VmFunction intSeqConverter;
   private final @Nullable VmFunction listConverter;
   private final @Nullable VmFunction setConverter;
@@ -56,6 +57,7 @@ public final class PklConverter implements VmValueConverter<Object> {
     floatConverter = typeConverters.get(BaseModule.getFloatClass());
     durationConverter = typeConverters.get(BaseModule.getDurationClass());
     dataSizeConverter = typeConverters.get(BaseModule.getDataSizeClass());
+    bytesConverter = typeConverters.get(BaseModule.getBytesClass());
     intSeqConverter = typeConverters.get(BaseModule.getIntSeqClass());
     listConverter = typeConverters.get(BaseModule.getListClass());
     setConverter = typeConverters.get(BaseModule.getSetClass());
@@ -100,6 +102,11 @@ public final class PklConverter implements VmValueConverter<Object> {
     return doConvert(value, path, dataSizeConverter);
   }
 
+  @Override
+  public Object convertBytes(VmBytes value, Iterable<Object> path) {
+    return doConvert(value, path, bytesConverter);
+  }
+
   @Override
   public Object convertIntSeq(VmIntSeq value, Iterable<Object> path) {
     return doConvert(value, path, intSeqConverter);

pkl-core/src/main/java/org/pkl/core/stdlib/base/BaseNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -142,4 +142,13 @@ public final class BaseNodes {
       return new VmIntSeq(first, second, 1L);
     }
   }
+
+  public abstract static class Bytes extends ExternalMethod1Node {
+    @Specialization
+    protected VmList eval(VirtualFrame frame, VmTyped self, Object args) {
+      // invocations of this method are handled specially in AstBuilder
+      CompilerDirectives.transferToInterpreter();
+      throw exceptionBuilder().bug("Node `BaseNodes.Bytes` should never be executed.").build();
+    }
+  }
 }

pkl-core/src/main/java/org/pkl/core/stdlib/base/BytesNodes.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pkl.core.stdlib.base;
+
+import com.oracle.truffle.api.CompilerDirectives;
+import com.oracle.truffle.api.dsl.Specialization;
+import java.nio.ByteBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.Charset;
+import org.pkl.core.runtime.VmBytes;
+import org.pkl.core.runtime.VmDataSize;
+import org.pkl.core.runtime.VmList;
+import org.pkl.core.runtime.VmNull;
+import org.pkl.core.stdlib.ExternalMethod0Node;
+import org.pkl.core.stdlib.ExternalMethod1Node;
+import org.pkl.core.stdlib.ExternalPropertyNode;
+import org.pkl.core.util.ByteArrayUtils;
+
+public final class BytesNodes {
+  private BytesNodes() {}
+
+  public abstract static class toList extends ExternalMethod0Node {
+    @Specialization
+    protected VmList eval(VmBytes self) {
+      return self.toList();
+    }
+  }
+
+  public abstract static class length extends ExternalPropertyNode {
+    @Specialization
+    protected long eval(VmBytes self) {
+      return self.getLength();
+    }
+  }
+
+  public abstract static class size extends ExternalPropertyNode {
+    @Specialization
+    protected VmDataSize eval(VmBytes self) {
+      return self.getSize();
+    }
+  }
+
+  public abstract static class base64 extends ExternalPropertyNode {
+    @Specialization
+    protected String eval(VmBytes self) {
+      return self.base64();
+    }
+  }
+
+  public abstract static class hex extends ExternalPropertyNode {
+    @Specialization
+    protected String eval(VmBytes self) {
+      return self.hex();
+    }
+  }
+
+  public abstract static class md5 extends ExternalPropertyNode {
+    @Specialization
+    protected String eval(VmBytes self) {
+      return ByteArrayUtils.md5(self.getBytes());
+    }
+  }
+
+  public abstract static class sha1 extends ExternalPropertyNode {
+    @Specialization
+    protected String eval(VmBytes self) {
+      return ByteArrayUtils.sha1(self.getBytes());
+    }
+  }
+
+  public abstract static class sha256 extends ExternalPropertyNode {
+    @Specialization
+    protected String eval(VmBytes self) {
+      return ByteArrayUtils.sha256(self.getBytes());
+    }
+  }
+
+  public abstract static class sha256Int extends ExternalPropertyNode {
+    @Specialization
+    protected long eval(VmBytes self) {
+      return ByteArrayUtils.sha256Int(self.getBytes());
+    }
+  }
+
+  public abstract static class getOrNull extends ExternalMethod1Node {
+    @Specialization
+    protected Object eval(VmBytes self, long index) {
+      if (index < 0 || index >= self.getLength()) {
+        return VmNull.withoutDefault();
+      }
+      return self.get(index);
+    }
+  }
+
+  public abstract static class decodeToString extends ExternalMethod1Node {
+    @Specialization
+    protected String eval(VmBytes self, String charset) {
+      try {
+        var byteBuffer = ByteBuffer.wrap(self.getBytes());
+        var decoder = Charset.forName(charset).newDecoder();
+        return decoder.decode(byteBuffer).toString();
+      } catch (CharacterCodingException e) {
+        CompilerDirectives.transferToInterpreter();
+        throw exceptionBuilder().evalError("characterCodingException", charset).build();
+      }
+    }
+  }
+}

pkl-core/src/main/java/org/pkl/core/stdlib/base/JsonRendererNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -126,6 +126,11 @@ public final class JsonRendererNodes {
       cannotRenderTypeAddConverter(value);
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      cannotRenderTypeAddConverter(value);
+    }
+
     @Override
     public void visitRegex(VmRegex value) {
       cannotRenderTypeAddConverter(value);

pkl-core/src/main/java/org/pkl/core/stdlib/base/ListNodes.java

@@ -18,17 +18,22 @@ package org.pkl.core.stdlib.base;
 import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Specialization;
+import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.LoopNode;
 import org.pkl.core.ast.expression.binary.*;
 import org.pkl.core.ast.internal.IsInstanceOfNode;
 import org.pkl.core.ast.internal.IsInstanceOfNodeGen;
 import org.pkl.core.ast.lambda.*;
+import org.pkl.core.ast.type.TypeNode;
+import org.pkl.core.ast.type.TypeNode.UInt8TypeAliasTypeNode;
+import org.pkl.core.ast.type.VmTypeMismatchException;
 import org.pkl.core.runtime.*;
 import org.pkl.core.stdlib.*;
 import org.pkl.core.stdlib.base.CollectionNodes.CompareByNode;
 import org.pkl.core.stdlib.base.CollectionNodes.CompareNode;
 import org.pkl.core.stdlib.base.CollectionNodes.CompareWithNode;
 import org.pkl.core.util.EconomicSets;
+import org.pkl.core.util.LateInit;
 
 // duplication between ListNodes and SetNodes is "intentional"
 // (sharing nodes between VmCollection subtypes results in
@@ -1321,4 +1326,34 @@ public final class ListNodes {
       return self.toDynamic();
     }
   }
+
+  public abstract static class toBytes extends ExternalMethod0Node {
+
+    @Child @LateInit private TypeNode typeNode;
+
+    private TypeNode getTypeNode() {
+      if (typeNode == null) {
+        CompilerDirectives.transferToInterpreterAndInvalidate();
+        typeNode = new UInt8TypeAliasTypeNode();
+      }
+      return typeNode;
+    }
+
+    @Specialization
+    protected VmBytes eval(VirtualFrame frame, VmList self) {
+      var typeNode = getTypeNode();
+      var bytes = new byte[self.getLength()];
+      try {
+        for (var i = 0; i < self.getLength(); i++) {
+          var elem = self.get(i);
+          var num = (Long) typeNode.executeEagerly(frame, elem);
+          bytes[i] = num.byteValue();
+        }
+      } catch (VmTypeMismatchException e) {
+        CompilerDirectives.transferToInterpreter();
+        throw e.toVmException();
+      }
+      return new VmBytes(self, bytes);
+    }
+  }
 }

pkl-core/src/main/java/org/pkl/core/stdlib/base/PListRendererNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,7 +54,6 @@ public final class PListRendererNodes {
   }
 
   // keep in sync with org.pkl.core.PListRenderer
-  @SuppressWarnings("HttpUrlsUsage")
   private static final class PListRenderer extends AbstractRenderer {
 
     // it's safe (though not required) to escape all the following characters in XML text nodes
@@ -124,6 +123,13 @@ public final class PListRendererNodes {
           .build();
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      builder.append("<data>");
+      builder.append(value.base64());
+      builder.append("</data>");
+    }
+
     @Override
     public void visitRegex(VmRegex value) {
       throw new VmExceptionBuilder()

pkl-core/src/main/java/org/pkl/core/stdlib/base/PcfRenderer.java

@@ -17,6 +17,7 @@ package org.pkl.core.stdlib.base;
 
 import org.pkl.core.ValueFormatter;
 import org.pkl.core.runtime.Identifier;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmDataSize;
 import org.pkl.core.runtime.VmDuration;
 import org.pkl.core.runtime.VmDynamic;
@@ -99,6 +100,11 @@ public final class PcfRenderer extends AbstractRenderer {
     builder.append(value);
   }
 
+  @Override
+  public void visitBytes(VmBytes value) {
+    builder.append(value);
+  }
+
   @Override
   public void visitPair(VmPair value) {
     builder.append("Pair(");

pkl-core/src/main/java/org/pkl/core/stdlib/base/PropertiesRendererNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.pkl.core.stdlib.base;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Specialization;
 import org.pkl.core.runtime.Identifier;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmDataSize;
 import org.pkl.core.runtime.VmDuration;
 import org.pkl.core.runtime.VmDynamic;
@@ -117,6 +118,11 @@ public final class PropertiesRendererNodes {
       cannotRenderTypeAddConverter(value);
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      cannotRenderTypeAddConverter(value);
+    }
+
     @Override
     public void visitIntSeq(VmIntSeq value) {
       cannotRenderTypeAddConverter(value);

pkl-core/src/main/java/org/pkl/core/stdlib/base/ResourceNodes.java

@@ -1,102 +0,0 @@
-/*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.pkl.core.stdlib.base;
-
-import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
-import com.oracle.truffle.api.dsl.Specialization;
-import java.util.*;
-import org.pkl.core.resource.Resource;
-import org.pkl.core.runtime.Identifier;
-import org.pkl.core.runtime.VmTyped;
-import org.pkl.core.runtime.VmUtils;
-import org.pkl.core.stdlib.ExternalPropertyNode;
-import org.pkl.core.util.ByteArrayUtils;
-
-public final class ResourceNodes {
-  private ResourceNodes() {}
-
-  public abstract static class md5 extends ExternalPropertyNode {
-    @TruffleBoundary
-    @Specialization(guards = "self.hasExtraStorage()")
-    protected String evalWithExtraStorage(VmTyped self) {
-      var resource = (Resource) self.getExtraStorage();
-      return ByteArrayUtils.md5(resource.bytes());
-    }
-
-    @TruffleBoundary
-    @Specialization(guards = "!self.hasExtraStorage()")
-    protected String evalWithoutExtraStorage(VmTyped self) {
-      // `pkl.base#Resource` is designed to allow direct instantiation,
-      // in which case it isn't backed by a `org.pkl.core.resource.Resource`.
-      // It seems the best we can do here
-      // is to expect `pkl.base#Resource.base64` to be set and decode it.
-      var base64 = (String) VmUtils.readMember(self, Identifier.BASE64);
-      var bytes = Base64.getDecoder().decode(base64);
-      return ByteArrayUtils.md5(bytes);
-    }
-  }
-
-  public abstract static class sha1 extends ExternalPropertyNode {
-    @TruffleBoundary
-    @Specialization(guards = "self.hasExtraStorage()")
-    protected String evalWithExtraStorage(VmTyped self) {
-      var resource = (Resource) self.getExtraStorage();
-      return ByteArrayUtils.sha1(resource.bytes());
-    }
-
-    @TruffleBoundary
-    @Specialization(guards = "!self.hasExtraStorage()")
-    protected String evalWithoutExtraStorage(VmTyped self) {
-      var base64 = (String) VmUtils.readMember(self, Identifier.BASE64);
-      var bytes = Base64.getDecoder().decode(base64);
-      return ByteArrayUtils.sha1(bytes);
-    }
-  }
-
-  public abstract static class sha256 extends ExternalPropertyNode {
-    @TruffleBoundary
-    @Specialization(guards = "self.hasExtraStorage()")
-    protected String evalWithExtraStorage(VmTyped self) {
-      var resource = (Resource) self.getExtraStorage();
-      return ByteArrayUtils.sha256(resource.bytes());
-    }
-
-    @TruffleBoundary
-    @Specialization(guards = "!self.hasExtraStorage()")
-    protected String evalWithoutExtraStorage(VmTyped self) {
-      var base64 = (String) VmUtils.readMember(self, Identifier.BASE64);
-      var bytes = Base64.getDecoder().decode(base64);
-      return ByteArrayUtils.sha256(bytes);
-    }
-  }
-
-  public abstract static class sha256Int extends ExternalPropertyNode {
-    @TruffleBoundary
-    @Specialization(guards = "self.hasExtraStorage()")
-    protected long evalWithExtraStorage(VmTyped self) {
-      var resource = (Resource) self.getExtraStorage();
-      return ByteArrayUtils.sha256Int(resource.bytes());
-    }
-
-    @TruffleBoundary
-    @Specialization(guards = "!self.hasExtraStorage()")
-    protected long evalWithoutExtraStorage(VmTyped self) {
-      var base64 = (String) VmUtils.readMember(self, Identifier.BASE64);
-      var bytes = Base64.getDecoder().decode(base64);
-      return ByteArrayUtils.sha256Int(bytes);
-    }
-  }
-}

pkl-core/src/main/java/org/pkl/core/stdlib/base/StringNodes.java

@@ -19,9 +19,11 @@ import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.LoopNode;
+import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
 import java.util.regex.*;
+import org.pkl.core.PklBugException;
 import org.pkl.core.ast.lambda.ApplyVmFunction1Node;
 import org.pkl.core.ast.lambda.ApplyVmFunction1NodeGen;
 import org.pkl.core.runtime.*;
@@ -149,6 +151,19 @@ public final class StringNodes {
     }
   }
 
+  public abstract static class isBase64 extends ExternalPropertyNode {
+    @Specialization
+    @TruffleBoundary
+    protected boolean eval(String self) {
+      try {
+        Base64.getDecoder().decode(self);
+        return true;
+      } catch (IllegalArgumentException e) {
+        return false;
+      }
+    }
+  }
+
   public abstract static class chars extends ExternalPropertyNode {
     @Specialization
     @TruffleBoundary
@@ -900,7 +915,7 @@ public final class StringNodes {
     @TruffleBoundary
     @Specialization
     protected String eval(String self) {
-      return Base64.getEncoder().encodeToString(self.getBytes(StandardCharsets.UTF_8));
+      return ByteArrayUtils.base64(self.getBytes(StandardCharsets.UTF_8));
     }
   }
 
@@ -920,6 +935,35 @@ public final class StringNodes {
     }
   }
 
+  public abstract static class base64DecodedBytes extends ExternalPropertyNode {
+    @TruffleBoundary
+    @Specialization
+    protected VmBytes eval(String self) {
+      try {
+        return new VmBytes(Base64.getDecoder().decode(self));
+      } catch (IllegalArgumentException e) {
+        throw exceptionBuilder()
+            .adhocEvalError(e.getMessage())
+            .withProgramValue("String", self)
+            .withCause(e)
+            .build();
+      }
+    }
+  }
+
+  public abstract static class encodeToBytes extends ExternalMethod1Node {
+    @TruffleBoundary
+    @Specialization
+    protected VmBytes eval(String self, String charsetName) {
+      try {
+        var bytes = self.getBytes(charsetName);
+        return new VmBytes(bytes);
+      } catch (UnsupportedEncodingException e) {
+        throw PklBugException.unreachableCode();
+      }
+    }
+  }
+
   @TruffleBoundary
   private static String substringFrom(String string, int start) {
     return string.substring(start);

pkl-core/src/main/java/org/pkl/core/stdlib/base/YamlRendererNodes.java

@@ -18,6 +18,7 @@ package org.pkl.core.stdlib.base;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Specialization;
 import org.pkl.core.runtime.Identifier;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmCollection;
 import org.pkl.core.runtime.VmDataSize;
 import org.pkl.core.runtime.VmDuration;
@@ -177,6 +178,11 @@ public final class YamlRendererNodes {
       cannotRenderTypeAddConverter(value);
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      cannotRenderTypeAddConverter(value);
+    }
+
     @Override
     public void visitRegex(VmRegex value) {
       cannotRenderTypeAddConverter(value);

pkl-core/src/main/java/org/pkl/core/stdlib/jsonnet/RendererNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.util.Set;
 import java.util.regex.Pattern;
 import org.pkl.core.runtime.Identifier;
 import org.pkl.core.runtime.JsonnetModule;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmDataSize;
 import org.pkl.core.runtime.VmDuration;
 import org.pkl.core.runtime.VmDynamic;
@@ -199,6 +200,11 @@ public final class RendererNodes {
       cannotRenderTypeAddConverter(value);
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      cannotRenderTypeAddConverter(value);
+    }
+
     @Override
     public void visitIntSeq(VmIntSeq value) {
       cannotRenderTypeAddConverter(value);

pkl-core/src/main/java/org/pkl/core/stdlib/protobuf/RendererNodes.java

@@ -44,6 +44,7 @@ import org.pkl.core.ast.type.TypeNode.UnionOfStringLiteralsTypeNode;
 import org.pkl.core.ast.type.TypeNode.UnionTypeNode;
 import org.pkl.core.ast.type.VmTypeMismatchException;
 import org.pkl.core.runtime.Identifier;
+import org.pkl.core.runtime.VmBytes;
 import org.pkl.core.runtime.VmClass;
 import org.pkl.core.runtime.VmDataSize;
 import org.pkl.core.runtime.VmDuration;
@@ -522,6 +523,14 @@ public final class RendererNodes {
           .build();
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      throw new VmExceptionBuilder()
+          .evalError("cannotRenderTypeAddConverter", "Bytes", "Protobuf")
+          .withProgramValue("Value", value)
+          .build();
+    }
+
     @Override
     public void visitIntSeq(VmIntSeq value) {
       writePropertyName();

pkl-core/src/main/java/org/pkl/core/stdlib/xml/RendererNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -154,6 +154,11 @@ public final class RendererNodes {
       cannotRenderTypeAddConverter(value);
     }
 
+    @Override
+    public void visitBytes(VmBytes value) {
+      cannotRenderTypeAddConverter(value);
+    }
+
     @Override
     public void visitPair(VmPair value) {
       cannotRenderTypeAddConverter(value);

pkl-core/src/main/java/org/pkl/core/util/ByteArrayUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,11 +17,16 @@ package org.pkl.core.util;
 
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Base64;
 import org.pkl.core.runtime.VmExceptionBuilder;
 
 public final class ByteArrayUtils {
   private ByteArrayUtils() {}
 
+  public static String base64(byte[] input) {
+    return Base64.getEncoder().encodeToString(input);
+  }
+
   public static String md5(byte[] input) {
     return hash(input, "MD5");
   }

pkl-core/src/main/resources/org/pkl/core/errorMessages.properties

@@ -1064,3 +1064,9 @@ External reader process has already terminated.
 invalidOpaqueFileUri=\
 File URIs must have a path that starts with `/` (e.g. file:/path/to/my_module.pkl).\n\
 To resolve relative paths, remove the scheme prefix (remove "file:").
+
+invalidStringBase64=\
+`{0}` is not in base64 encoding.
+
+characterCodingException=\
+Invalid bytes for charset "{0}".

pkl-core/src/test/files/LanguageSnippetTests/input/api/bytes.pkl

@@ -0,0 +1,51 @@
+amends "../snippetTest.pkl"
+
+local megaBytes = IntSeq(0, 999).map((_) -> 0).toBytes()
+
+examples {
+  ["md5"] {
+    Bytes(1, 2, 3, 4).md5
+    Bytes().md5
+  }
+  ["sha256"] {
+    Bytes(1, 2, 3, 4).sha256
+    Bytes().sha256
+  }
+  ["sha1"] {
+    Bytes(1, 2, 3, 4).sha1
+    Bytes().sha1
+  }
+  ["toString"] {
+    Bytes(1, 2, 3, 4).toString()
+    Bytes().toString()
+  }
+  ["base64"] {
+    Bytes(1, 2, 3, 4).base64
+    Bytes().base64
+    "AQIDBA==".base64DecodedBytes.base64
+  }
+  ["hex"] {
+    Bytes(1, 2, 3, 4).hex
+    Bytes().hex
+  }
+  ["length"] {
+    Bytes().length
+    Bytes(1, 2, 3, 4).length
+    megaBytes.length
+  }
+  ["size"] {
+    Bytes().size
+    Bytes(1, 2, 3, 4).size
+    megaBytes.size
+  }
+  ["decodeToString()"] {
+    Bytes(0x66, 0x6f, 0x6f, 0x20, 0x62, 0x61, 0x72).decodeToString("UTF-8")
+    "foo bar".encodeToBytes("UTF-8").decodeToString("UTF-8")
+  }
+  ["getOrNull()"] {
+    Bytes(1, 2, 3).getOrNull(0)
+    Bytes(1, 2, 3).getOrNull(1)
+    Bytes(1, 2, 3).getOrNull(2)
+    Bytes(1, 2, 3).getOrNull(3)
+  }
+}

pkl-core/src/test/files/LanguageSnippetTests/input/api/list.pkl

@@ -358,6 +358,13 @@ examples {
     List().toDynamic()
   }
   
+  ["toBytes()"] {
+    list1.toBytes()
+    List().toBytes()
+    module.catch(() -> List(null).toBytes())
+    module.catch(() -> List(-1).toBytes())
+  }
+
   ["filterNonNull()"] {
     list1.filterNonNull()
     List().filterNonNull()

pkl-core/src/test/files/LanguageSnippetTests/input/api/string.pkl

@@ -18,6 +18,12 @@ facts {
     !str1.isBlank
   }
 
+  ["isBase64"] {
+    "".isBase64
+    "AQIDBA==".isBase64
+    !"hello there".isBase64
+  }
+
   ["lastIndex"] {
     for (s in List(str1, str2, str3)) {
       s.length == s.lastIndex + 1
@@ -29,6 +35,10 @@ facts {
     quickBrownFox.base64.base64Decoded == quickBrownFox
   }
   
+  ["base64DecodedBytes"] {
+    "AQIDBA==".base64DecodedBytes == Bytes(1, 2, 3, 4)
+  }
+
   ["contains()"] {
     str1.contains(str2)
     str1.contains(str1)
@@ -487,4 +497,19 @@ examples {
   ["base64Decoded"] {
     module.catch(() -> "~~~".base64Decoded)
   }
+  
+  ["base64DecodedBytes"] {
+    module.catch(() -> "~~~".base64DecodedBytes)
+    "AQIDBA==".base64DecodedBytes
+  }
+  
+  ["encodeToBytes()"] {
+    "~~~".encodeToBytes("UTF-8")
+    "🏀".encodeToBytes("UTF-8")
+    "~~~".encodeToBytes("UTF-16")
+    "🏀".encodeToBytes("UTF-16")
+    "~~~".encodeToBytes("ISO-8859-1")
+    "🏀".encodeToBytes("ISO-8859-1")
+    "Parrot".encodeToBytes("UTF-8")
+  }
 }

pkl-core/src/test/files/LanguageSnippetTests/input/basic/bytes.pkl

@@ -0,0 +1,70 @@
+amends ".../snippetTest.pkl"
+
+local bytes1 = Bytes(1, 2, 3)
+local bytes2 = Bytes(1, 2, 4)
+
+examples {
+  ["basic"] {
+    Bytes(0, 255)
+  }
+
+  ["bytes from constant value nodes"] {
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+    Bytes(
+      0b000,
+      0b001,
+      0b010,
+      0b011,
+      0b100,
+      0b101,
+      0b110,
+      0b111
+    )
+    Bytes(0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7)
+    Bytes(0o0, 0o1, 0o2, 0o3, 0o4, 0o5, 0o6, 0o7)
+    Bytes(0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7)
+  }
+
+  ["bytes from non-constant value nodes"] {
+    local one = 1
+    local two = 2
+    Bytes(one, two)
+  }
+
+  ["incorrectly sized constant values"] {
+    module.catch(() -> Bytes(0, 1, 2, 0xffff))
+  }
+
+  ["equality"] {
+    bytes1 == bytes1
+    bytes1 == bytes2
+    bytes1 == bytes1.toList()
+    bytes1 == Bytes(1, 2, 3)
+  }
+
+  ["inequality"] {
+    bytes1 != bytes1
+    bytes1 != bytes2
+    bytes1 != bytes1.toList()
+    bytes1 != Bytes(1, 2, 3)
+  }
+
+  ["addition"] {
+    bytes1 + bytes2
+    Bytes() + Bytes()
+    bytes1 + Bytes()
+    Bytes() + bytes2
+    module.catch(() -> bytes1 + bytes2.toList())
+  }
+
+  ["subscript"] {
+    bytes1[0]
+    bytes1[1]
+    bytes1[2]
+    module.catch(() -> bytes1[3])
+  }
+
+  ["all bytes"] {
+    IntSeq(0, 255).toList().toBytes()
+  }
+}

pkl-core/src/test/files/LanguageSnippetTests/input/basic/list.pkl

@@ -37,5 +37,3 @@ examples {
     module.catch(() -> list1[3])
   }
 }
-
-

pkl-core/src/test/files/LanguageSnippetTests/input/errors/decodingException.pkl

@@ -0,0 +1 @@
+res = Bytes(0xc0, 0xc1).decodeToString("UTF-8")

pkl-core/src/test/files/LanguageSnippetTests/input/errors/invalidBytes1.pkl

@@ -0,0 +1 @@
+foo = Bytes(0, 1, 2, 3, 0xffff)

pkl-core/src/test/files/LanguageSnippetTests/input/errors/invalidBytes2.pkl

@@ -0,0 +1,3 @@
+local num = 0xfff
+
+res = Bytes(0, 1, 2, 3, num)

pkl-core/src/test/files/LanguageSnippetTests/input/errors/invalidBytes3.pkl

@@ -0,0 +1 @@
+bytes = Bytes(0, 1, 2, 3, 0xffff)

pkl-core/src/test/files/LanguageSnippetTests/input/errors/invalidBytes4.pkl

@@ -0,0 +1 @@
+res = List(1, 2, 3, 0xffff).toBytes()

pkl-core/src/test/files/LanguageSnippetTests/input/generators/elementGenerators.pkl

@@ -326,6 +326,18 @@ res11d = new Dynamic {
   for (i, n in IntSeq(1, 3)) { Pair(i, n) }
 }
 
+res12a = new Listing {
+  for (i in Bytes(1, 2, 3, 4)) {
+    i
+  }
+}
+
+res12b = new Listing {
+  for (i in Bytes()) {
+    i
+  }
+}
+
 local dynamicWithOnlyProperties = new Dynamic {
   foo = "Foo!"
   bar = 42

pkl-core/src/test/files/LanguageSnippetTests/input/generators/spreadSyntaxDynamic.pkl

@@ -15,6 +15,7 @@ local list: List<Int> = List(1, 2, 3)
 local map: Map<String, Int> = Map("zz", 1, "yy", 2)
 local intseq: IntSeq = IntSeq(0, 5).step(2)
 local set: Set<Int> = Set(10, 20, 30)
+local bytes: Bytes = Bytes(1, 2, 3, 4)
 
 examples {
   ["inferred Dynamic parent"] {
@@ -29,6 +30,7 @@ examples {
       ...map
       ...intseq
       ...set
+      ...bytes
     }
   }
   ["explicit Dynamic type"] {
@@ -43,6 +45,7 @@ examples {
       ...map
       ...intseq
       ...set
+      ...bytes
     }
   }
   ["legacy syntax"] {
@@ -52,6 +55,7 @@ examples {
     (Dynamic) { ...map }
     (Dynamic) { ...intseq }
     (Dynamic) { ...set }
+    (Dynamic) { ...bytes }
   }
 }
 

pkl-core/src/test/files/LanguageSnippetTests/input/generators/spreadSyntaxListing.pkl

@@ -6,6 +6,7 @@ local list: List<Int> = List(1, 2, 3)
 local map: Map<String, Int> = Map("a", 1, "b", 2)
 local intseq: IntSeq = IntSeq(0, 5).step(2)
 local set: Set<Int> = Set(10, 20, 30)
+local bytes: Bytes = Bytes(1, 2, 3, 4)
 
 res1: Listing = new {
   0
@@ -72,3 +73,15 @@ res16 = new Listing {
 }
 
 res17 = res16.length
+
+res18 = new Listing {
+  ...bytes
+}
+
+res19 = new Listing {
+  0
+  ...bytes
+  0
+  0
+  0
+}

pkl-core/src/test/files/LanguageSnippetTests/input/generators/spreadSyntaxMapping.pkl

@@ -15,6 +15,7 @@ local list: List<Int> = List(1, 2, 3)
 local map: Map<String, Int> = Map("a", 1, "b", 2)
 local intseq: IntSeq = IntSeq(0, 5).step(2)
 local set: Set<Int> = Set(10, 20, 30)
+local bytes: Bytes = Bytes(1, 2, 3, 4)
 
 class Foo {
   names: Listing<String>
@@ -108,3 +109,5 @@ local foos = (makeFoos(List("bar"))) {
 res17 = new Mapping {
   ...foos
 }
+
+res18 = test.catch(() -> new Mapping { ...bytes })

pkl-core/src/test/files/LanguageSnippetTests/output/api/bytes.pcf

@@ -0,0 +1,47 @@
+examples {
+  ["md5"] {
+    "08d6c05a21512a79a1dfeb9d2a8f262f"
+    "d41d8cd98f00b204e9800998ecf8427e"
+  }
+  ["sha256"] {
+    "9f64a747e1b97f131fabb6b447296c9b6f0201e79fb3c5356e6c77e89b6a806a"
+    "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  }
+  ["sha1"] {
+    "12dada1fff4d4787ade3333147202c3b443e376f"
+    "da39a3ee5e6b4b0d3255bfef95601890afd80709"
+  }
+  ["toString"] {
+    "Bytes(1, 2, 3, 4)"
+    "Bytes()"
+  }
+  ["base64"] {
+    "AQIDBA=="
+    ""
+    "AQIDBA=="
+  }
+  ["hex"] {
+    "01020304"
+    ""
+  }
+  ["length"] {
+    0
+    4
+    1000
+  }
+  ["size"] {
+    0.b
+    4.b
+    1.kb
+  }
+  ["decodeToString()"] {
+    "foo bar"
+    "foo bar"
+  }
+  ["getOrNull()"] {
+    1
+    2
+    3
+    null
+  }
+}

pkl-core/src/test/files/LanguageSnippetTests/output/api/list.pcf

@@ -303,6 +303,12 @@ examples {
     }
     new {}
   }
+  ["toBytes()"] {
+    Bytes(1, 2, 3)
+    Bytes()
+    "Expected value of type `Int`, but got `null`."
+    "Type constraint `isBetween(0, 255)` violated. Value: -1"
+  }
   ["filterNonNull()"] {
     List(1, 2, 3)
     List()

pkl-core/src/test/files/LanguageSnippetTests/output/api/reflectedDeclaration.pcf

@@ -13,9 +13,9 @@ alias {
     members = List(new {
       referent {
         location {
-          line = 1040
+          line = 1056
           column = 1
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1040"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1056"
         }
         docComment = """
           A boolean value, either [true] or [false].
@@ -197,9 +197,9 @@ alias {
         properties = Map()
         methods = Map("xor", new {
           location {
-            line = 1050
+            line = 1066
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1050"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1066"
           }
           docComment = """
             Tells if exactly one of [this] and [other] is [true] (exclusive or).
@@ -221,9 +221,9 @@ alias {
           })
         }, "implies", new {
           location {
-            line = 1063
+            line = 1079
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1063"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1079"
           }
           docComment = """
             Tells if [this] implies [other] (logical consequence).
@@ -251,9 +251,9 @@ alias {
     }, new {
       referent {
         location {
-          line = 1076
+          line = 1092
           column = 1
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1076"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1092"
         }
         docComment = """
           A sequence of Unicode characters (code points).
@@ -433,9 +433,9 @@ alias {
         }
         properties = Map("length", new {
           location {
-            line = 1087
+            line = 1103
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1087"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1103"
           }
           docComment = """
             The number of characters in this string.
@@ -458,9 +458,9 @@ alias {
           name = "length"
         }, "lastIndex", new {
           location {
-            line = 1100
+            line = 1116
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1100"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1116"
           }
           docComment = """
             The index of the last character in this string (same as `length - 1`).
@@ -480,9 +480,9 @@ alias {
           name = "lastIndex"
         }, "isEmpty", new {
           location {
-            line = 1110
+            line = 1126
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1110"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1126"
           }
           docComment = """
             Tells whether this string is empty.
@@ -499,9 +499,9 @@ alias {
           name = "isEmpty"
         }, "isBlank", new {
           location {
-            line = 1121
+            line = 1137
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1121"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1137"
           }
           docComment = """
             Tells if all characters in this string have Unicode property "White_Space".
@@ -519,19 +519,39 @@ alias {
           name = "isBlank"
         }, "isRegex", new {
           location {
-            line = 1124
+            line = 1140
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1124"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1140"
           }
           docComment = "Tells if this string is a valid regular expression according to [Regex]."
           annotations = List()
           modifiers = Set()
           name = "isRegex"
+        }, "isBase64", new {
+          location {
+            line = 1150
+            column = 3
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1150"
+          }
+          docComment = """
+            Tells if this is a valid base64-encoded string.
+            
+            Facts:
+            ```
+            "AQIDBA==".isBase64
+            !"hello there".isBase64
+            ```
+            """
+          annotations = List(new {
+            version = "0.29.0"
+          })
+          modifiers = Set()
+          name = "isBase64"
         }, "md5", new {
           location {
-            line = 1131
+            line = 1157
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1131"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1157"
           }
           docComment = """
             The [MD5](https://en.wikipedia.org/wiki/MD5)
@@ -545,9 +565,9 @@ alias {
           name = "md5"
         }, "sha1", new {
           location {
-            line = 1137
+            line = 1163
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1137"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1163"
           }
           docComment = """
             The [SHA-1](https://en.wikipedia.org/wiki/SHA-1)
@@ -560,9 +580,9 @@ alias {
           name = "sha1"
         }, "sha256", new {
           location {
-            line = 1142
+            line = 1168
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1142"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1168"
           }
           docComment = """
             The [SHA-256](https://en.wikipedia.org/wiki/SHA-2)
@@ -574,9 +594,9 @@ alias {
           name = "sha256"
         }, "sha256Int", new {
           location {
-            line = 1146
+            line = 1172
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1146"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1172"
           }
           docComment = """
             The first 64 bits of the [SHA-256](https://en.wikipedia.org/wiki/SHA-2)
@@ -587,9 +607,9 @@ alias {
           name = "sha256Int"
         }, "base64", new {
           location {
-            line = 1149
+            line = 1175
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1149"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1175"
           }
           docComment = "The Base64 encoding of this string's UTF-8 byte sequence."
           annotations = List()
@@ -597,9 +617,9 @@ alias {
           name = "base64"
         }, "base64Decoded", new {
           location {
-            line = 1157
+            line = 1183
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1157"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1183"
           }
           docComment = """
             The inverse of [base64].
@@ -612,11 +632,30 @@ alias {
           annotations = List()
           modifiers = Set()
           name = "base64Decoded"
+        }, "base64DecodedBytes", new {
+          location {
+            line = 1192
+            column = 3
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1192"
+          }
+          docComment = """
+            Converts this base64-format string into [Bytes].
+            
+            Facts:
+            ```
+            "AQIDBA==".base64DecodedBytes = Bytes(1, 2, 3, 4)
+            ```
+            """
+          annotations = List(new {
+            version = "0.29.0"
+          })
+          modifiers = Set()
+          name = "base64DecodedBytes"
         }, "chars", new {
           location {
-            line = 1165
+            line = 1200
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1165"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1200"
           }
           docComment = """
             The Unicode characters in this string.
@@ -631,9 +670,9 @@ alias {
           name = "chars"
         }, "codePoints", new {
           location {
-            line = 1173
+            line = 1208
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1173"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1208"
           }
           docComment = """
             The Unicode code points in this string.
@@ -649,9 +688,9 @@ alias {
         })
         methods = Map("getOrNull", new {
           location {
-            line = 1185
+            line = 1220
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1185"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1220"
           }
           docComment = """
             Returns the character at [index], or [null] if [index] is out of range.
@@ -674,9 +713,9 @@ alias {
           })
         }, "substring", new {
           location {
-            line = 1199
+            line = 1234
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1199"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1234"
           }
           docComment = """
             Returns the substring from [start] until [exclusiveEnd].
@@ -703,9 +742,9 @@ alias {
           })
         }, "substringOrNull", new {
           location {
-            line = 1217
+            line = 1252
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1217"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1252"
           }
           docComment = """
             Returns the substring from [start] until [exclusiveEnd].
@@ -736,9 +775,9 @@ alias {
           })
         }, "repeat", new {
           location {
-            line = 1227
+            line = 1262
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1227"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1262"
           }
           docComment = """
             Concatenates [count] copies of this string.
@@ -759,9 +798,9 @@ alias {
           })
         }, "contains", new {
           location {
-            line = 1230
+            line = 1265
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1230"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1265"
           }
           docComment = "Tells whether this string contains [pattern]."
           annotations = List()
@@ -773,9 +812,9 @@ alias {
           })
         }, "matches", new {
           location {
-            line = 1234
+            line = 1269
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1234"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1269"
           }
           docComment = "Tells whether this string matches [regex] in its entirety."
           annotations = List(new {
@@ -791,9 +830,9 @@ alias {
           })
         }, "startsWith", new {
           location {
-            line = 1237
+            line = 1272
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1237"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1272"
           }
           docComment = "Tells whether this string starts with [pattern]."
           annotations = List()
@@ -805,9 +844,9 @@ alias {
           })
         }, "endsWith", new {
           location {
-            line = 1240
+            line = 1275
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1240"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1275"
           }
           docComment = "Tells whether this string ends with [pattern]."
           annotations = List()
@@ -819,9 +858,9 @@ alias {
           })
         }, "indexOf", new {
           location {
-            line = 1246
+            line = 1281
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1246"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1281"
           }
           docComment = """
             Returns the zero-based index of the first occurrence of [pattern]
@@ -838,9 +877,9 @@ alias {
           })
         }, "indexOfOrNull", new {
           location {
-            line = 1250
+            line = 1285
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1250"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1285"
           }
           docComment = """
             Returns the zero-based index of the first occurrence of [pattern]
@@ -855,9 +894,9 @@ alias {
           })
         }, "lastIndexOf", new {
           location {
-            line = 1256
+            line = 1291
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1256"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1291"
           }
           docComment = """
             Returns the zero-based index of the last occurrence of [pattern]
@@ -874,9 +913,9 @@ alias {
           })
         }, "lastIndexOfOrNull", new {
           location {
-            line = 1260
+            line = 1295
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1260"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1295"
           }
           docComment = """
             Returns the zero-based index of the last occurrence of [pattern]
@@ -891,9 +930,9 @@ alias {
           })
         }, "take", new {
           location {
-            line = 1266
+            line = 1301
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1266"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1301"
           }
           docComment = """
             Returns the first [n] characters of this string.
@@ -913,9 +952,9 @@ alias {
           })
         }, "takeWhile", new {
           location {
-            line = 1269
+            line = 1304
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1269"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1304"
           }
           docComment = "Returns the longest prefix of this string that satisfies [predicate]."
           annotations = List()
@@ -927,9 +966,9 @@ alias {
           })
         }, "takeLast", new {
           location {
-            line = 1274
+            line = 1309
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1274"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1309"
           }
           docComment = """
             Returns the last [n] characters of this string.
@@ -945,9 +984,9 @@ alias {
           })
         }, "takeLastWhile", new {
           location {
-            line = 1277
+            line = 1312
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1277"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1312"
           }
           docComment = "Returns the longest suffix of this string that satisfies [predicate]."
           annotations = List()
@@ -959,9 +998,9 @@ alias {
           })
         }, "drop", new {
           location {
-            line = 1283
+            line = 1318
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1283"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1318"
           }
           docComment = """
             Removes the first [n] characters of this string.
@@ -981,9 +1020,9 @@ alias {
           })
         }, "dropWhile", new {
           location {
-            line = 1287
+            line = 1322
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1287"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1322"
           }
           docComment = "Removes the longest prefix of this string that satisfies [predicate]."
           annotations = List(new {
@@ -999,9 +1038,9 @@ alias {
           })
         }, "dropLast", new {
           location {
-            line = 1293
+            line = 1328
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1293"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1328"
           }
           docComment = """
             Removes the last [n] characters of this string.
@@ -1021,9 +1060,9 @@ alias {
           })
         }, "dropLastWhile", new {
           location {
-            line = 1297
+            line = 1332
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1297"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1332"
           }
           docComment = "Removes the longest suffix of this string that satisfies [predicate]."
           annotations = List(new {
@@ -1039,9 +1078,9 @@ alias {
           })
         }, "replaceFirst", new {
           location {
-            line = 1302
+            line = 1337
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1302"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1337"
           }
           docComment = """
             Replaces the first occurrence of [pattern] in this string with [replacement].
@@ -1059,9 +1098,9 @@ alias {
           })
         }, "replaceLast", new {
           location {
-            line = 1307
+            line = 1342
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1307"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1342"
           }
           docComment = """
             Replaces the last occurrence of [pattern] in this string with [replacement].
@@ -1079,9 +1118,9 @@ alias {
           })
         }, "replaceAll", new {
           location {
-            line = 1312
+            line = 1347
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1312"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1347"
           }
           docComment = """
             Replaces all occurrences of [pattern] in this string with [replacement].
@@ -1099,9 +1138,9 @@ alias {
           })
         }, "replaceFirstMapped", new {
           location {
-            line = 1317
+            line = 1352
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1317"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1352"
           }
           docComment = """
             Replaces the first occurrence of [pattern] in this string with the return value of [mapper].
@@ -1119,9 +1158,9 @@ alias {
           })
         }, "replaceLastMapped", new {
           location {
-            line = 1322
+            line = 1357
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1322"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1357"
           }
           docComment = """
             Replaces the last occurrence of [pattern] in this string with the return value of [mapper].
@@ -1139,9 +1178,9 @@ alias {
           })
         }, "replaceAllMapped", new {
           location {
-            line = 1327
+            line = 1362
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1327"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1362"
           }
           docComment = """
             Replaces all occurrences of [pattern] in this string with the return value of [mapper].
@@ -1159,9 +1198,9 @@ alias {
           })
         }, "replaceRange", new {
           location {
-            line = 1332
+            line = 1367
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1332"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1367"
           }
           docComment = """
             Replaces the characters between [start] and [exclusiveEnd] with [replacement].
@@ -1181,9 +1220,9 @@ alias {
           })
         }, "toUpperCase", new {
           location {
-            line = 1335
+            line = 1370
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1335"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1370"
           }
           docComment = "Performs a locale-independent character-by-character conversion of this string to uppercase."
           annotations = List()
@@ -1193,9 +1232,9 @@ alias {
           parameters = Map()
         }, "toLowerCase", new {
           location {
-            line = 1338
+            line = 1373
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1338"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1373"
           }
           docComment = "Performs a locale-independent character-by-character conversion of this string to lowercase."
           annotations = List()
@@ -1205,9 +1244,9 @@ alias {
           parameters = Map()
         }, "reverse", new {
           location {
-            line = 1341
+            line = 1376
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1341"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1376"
           }
           docComment = "Reverses the order of characters in this string."
           annotations = List()
@@ -1217,9 +1256,9 @@ alias {
           parameters = Map()
         }, "trim", new {
           location {
-            line = 1345
+            line = 1380
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1345"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1380"
           }
           docComment = "Removes any leading and trailing characters with Unicode property \"White_Space\" from this string."
           annotations = List(new {
@@ -1233,9 +1272,9 @@ alias {
           parameters = Map()
         }, "trimStart", new {
           location {
-            line = 1349
+            line = 1384
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1349"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1384"
           }
           docComment = "Removes any leading characters with Unicode property \"White_Space\" from this string."
           annotations = List(new {
@@ -1253,9 +1292,9 @@ alias {
           parameters = Map()
         }, "trimEnd", new {
           location {
-            line = 1353
+            line = 1388
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1353"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1388"
           }
           docComment = "Removes any trailing characters with Unicode property \"White_Space\" from this string."
           annotations = List(new {
@@ -1273,9 +1312,9 @@ alias {
           parameters = Map()
         }, "padStart", new {
           location {
-            line = 1359
+            line = 1394
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1359"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1394"
           }
           docComment = """
             Increases the length of this string to [width] by adding leading [char]s.
@@ -1297,9 +1336,9 @@ alias {
           })
         }, "padEnd", new {
           location {
-            line = 1365
+            line = 1400
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1365"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1400"
           }
           docComment = """
             Increases the length of this string to [width] by adding trailing [char]s.
@@ -1321,9 +1360,9 @@ alias {
           })
         }, "split", new {
           location {
-            line = 1368
+            line = 1403
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1368"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1403"
           }
           docComment = "Splits this string around matches of [pattern]."
           annotations = List()
@@ -1335,9 +1374,9 @@ alias {
           })
         }, "splitLimit", new {
           location {
-            line = 1383
+            line = 1418
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1383"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1418"
           }
           docComment = """
             Splits this string matches of [pattern], up to [limit] substrings.
@@ -1366,9 +1405,9 @@ alias {
           })
         }, "capitalize", new {
           location {
-            line = 1393
+            line = 1428
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1393"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1428"
           }
           docComment = """
             Converts the first character of this string to title case.
@@ -1387,9 +1426,9 @@ alias {
           parameters = Map()
         }, "decapitalize", new {
           location {
-            line = 1403
+            line = 1438
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1403"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1438"
           }
           docComment = """
             Converts the first character of this string to lower case.
@@ -1408,9 +1447,9 @@ alias {
           parameters = Map()
         }, "toInt", new {
           location {
-            line = 1409
+            line = 1444
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1409"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1444"
           }
           docComment = """
             Parses this string as a signed decimal (base 10) integer.
@@ -1425,9 +1464,9 @@ alias {
           parameters = Map()
         }, "toIntOrNull", new {
           location {
-            line = 1415
+            line = 1450
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1415"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1450"
           }
           docComment = """
             Parses this string as a signed decimal (base 10) integer.
@@ -1442,9 +1481,9 @@ alias {
           parameters = Map()
         }, "toFloat", new {
           location {
-            line = 1420
+            line = 1455
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1420"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1455"
           }
           docComment = """
             Parses this string as a floating point number.
@@ -1458,9 +1497,9 @@ alias {
           parameters = Map()
         }, "toFloatOrNull", new {
           location {
-            line = 1425
+            line = 1460
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1425"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1460"
           }
           docComment = """
             Parses this string as a floating point number.
@@ -1474,9 +1513,9 @@ alias {
           parameters = Map()
         }, "toBoolean", new {
           location {
-            line = 1430
+            line = 1465
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1430"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1465"
           }
           docComment = """
             Parses `"true"` to [true] and `"false"` to [false] (case-insensitive).
@@ -1490,9 +1529,9 @@ alias {
           parameters = Map()
         }, "toBooleanOrNull", new {
           location {
-            line = 1435
+            line = 1470
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1435"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1470"
           }
           docComment = """
             Parses `"true"` to [true] and `"false"` to [false] (case-insensitive).
@@ -1504,6 +1543,29 @@ alias {
           name = "toBooleanOrNull"
           typeParameters = List()
           parameters = Map()
+        }, "encodeToBytes", new {
+          location {
+            line = 1479
+            column = 3
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1479"
+          }
+          docComment = """
+            Returns the bytes of this string, encoded using [charset]. 
+            
+            Facts:
+            ```
+            "Parrot".encodeToBytes("UTF-8") == Bytes(80, 97, 114, 114, 111, 116)
+            ```
+            """
+          annotations = List(new {
+            version = "0.29.0"
+          })
+          modifiers = Set()
+          name = "encodeToBytes"
+          typeParameters = List()
+          parameters = Map("charset", new {
+            name = "charset"
+          })
         })
       }
       typeArguments = List()
@@ -1524,9 +1586,9 @@ rec {
     typeParameters = List()
     superclass {
       location {
-        line = 1721
+        line = 1773
         column = 1
-        displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1721"
+        displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1773"
       }
       docComment = """
         Base class for objects whose members are described by a class definition.
@@ -1539,9 +1601,9 @@ rec {
       typeParameters = List()
       superclass {
         location {
-          line = 1716
+          line = 1768
           column = 1
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1716"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1768"
         }
         docComment = """
           A composite value containing members (properties, elements, entries).
@@ -1765,9 +1827,9 @@ rec {
       supertype {
         referent {
           location {
-            line = 1716
+            line = 1768
             column = 1
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1716"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1768"
           }
           docComment = """
             A composite value containing members (properties, elements, entries).
@@ -1993,9 +2055,9 @@ rec {
       properties = Map()
       methods = Map("hasProperty", new {
         location {
-          line = 1723
+          line = 1775
           column = 3
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1723"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1775"
         }
         docComment = "Tells if this object has a property with the given [name]."
         annotations = List()
@@ -2007,9 +2069,9 @@ rec {
         })
       }, "getProperty", new {
         location {
-          line = 1728
+          line = 1780
           column = 3
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1728"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1780"
         }
         docComment = """
           Returns the value of the property with the given [name].
@@ -2025,9 +2087,9 @@ rec {
         })
       }, "getPropertyOrNull", new {
         location {
-          line = 1733
+          line = 1785
           column = 3
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1733"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1785"
         }
         docComment = """
           Returns the value of the property with the given [name].
@@ -2043,9 +2105,9 @@ rec {
         })
       }, "toDynamic", new {
         location {
-          line = 1736
+          line = 1788
           column = 3
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1736"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1788"
         }
         docComment = "Converts this object to a [Dynamic] object."
         annotations = List()
@@ -2055,9 +2117,9 @@ rec {
         parameters = Map()
       }, "toMap", new {
         location {
-          line = 1739
+          line = 1791
           column = 3
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1739"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1791"
         }
         docComment = "Converts this object to a [Map]."
         annotations = List()
@@ -2070,9 +2132,9 @@ rec {
     supertype {
       referent {
         location {
-          line = 1721
+          line = 1773
           column = 1
-          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1721"
+          displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1773"
         }
         docComment = """
           Base class for objects whose members are described by a class definition.
@@ -2085,9 +2147,9 @@ rec {
         typeParameters = List()
         superclass {
           location {
-            line = 1716
+            line = 1768
             column = 1
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1716"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1768"
           }
           docComment = """
             A composite value containing members (properties, elements, entries).
@@ -2311,9 +2373,9 @@ rec {
         supertype {
           referent {
             location {
-              line = 1716
+              line = 1768
               column = 1
-              displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1716"
+              displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1768"
             }
             docComment = """
               A composite value containing members (properties, elements, entries).
@@ -2539,9 +2601,9 @@ rec {
         properties = Map()
         methods = Map("hasProperty", new {
           location {
-            line = 1723
+            line = 1775
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1723"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1775"
           }
           docComment = "Tells if this object has a property with the given [name]."
           annotations = List()
@@ -2553,9 +2615,9 @@ rec {
           })
         }, "getProperty", new {
           location {
-            line = 1728
+            line = 1780
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1728"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1780"
           }
           docComment = """
             Returns the value of the property with the given [name].
@@ -2571,9 +2633,9 @@ rec {
           })
         }, "getPropertyOrNull", new {
           location {
-            line = 1733
+            line = 1785
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1733"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1785"
           }
           docComment = """
             Returns the value of the property with the given [name].
@@ -2589,9 +2651,9 @@ rec {
           })
         }, "toDynamic", new {
           location {
-            line = 1736
+            line = 1788
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1736"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1788"
           }
           docComment = "Converts this object to a [Dynamic] object."
           annotations = List()
@@ -2601,9 +2663,9 @@ rec {
           parameters = Map()
         }, "toMap", new {
           location {
-            line = 1739
+            line = 1791
             column = 3
-            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1739"
+            displayUri = "https://github.com/apple/pkl/blob/$commitId/stdlib/base.pkl#L1791"
           }
           docComment = "Converts this object to a [Map]."
           annotations = List()

pkl-core/src/test/files/LanguageSnippetTests/output/api/string.pcf

@@ -9,6 +9,11 @@ facts {
     true
     true
   }
+  ["isBase64"] {
+    true
+    true
+    true
+  }
   ["lastIndex"] {
     true
     true
@@ -18,6 +23,9 @@ facts {
     true
     true
   }
+  ["base64DecodedBytes"] {
+    true
+  }
   ["contains()"] {
     true
     true
@@ -417,4 +425,17 @@ examples {
   ["base64Decoded"] {
     "Illegal base64 character 7e String: \"~~~\""
   }
+  ["base64DecodedBytes"] {
+    "Illegal base64 character 7e String: \"~~~\""
+    Bytes(1, 2, 3, 4)
+  }
+  ["encodeToBytes()"] {
+    Bytes(126, 126, 126)
+    Bytes(240, 159, 143, 128)
+    Bytes(254, 255, 0, 126, 0, 126, 0, 126)
+    Bytes(254, 255, 216, 60, 223, 192)
+    Bytes(126, 126, 126)
+    Bytes(63)
+    Bytes(80, 97, 114, 114, 111, 116)
+  }
 }

pkl-core/src/test/files/LanguageSnippetTests/output/basic/bytes.pcf

@@ -0,0 +1,46 @@
+examples {
+  ["basic"] {
+    Bytes(0, 255)
+  }
+  ["bytes from constant value nodes"] {
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7)
+  }
+  ["bytes from non-constant value nodes"] {
+    Bytes(1, 2)
+  }
+  ["incorrectly sized constant values"] {
+    "Type constraint `isBetween(0, 255)` violated. Value: 65535"
+  }
+  ["equality"] {
+    true
+    false
+    false
+    true
+  }
+  ["inequality"] {
+    false
+    true
+    true
+    false
+  }
+  ["addition"] {
+    Bytes(1, 2, 3, 1, 2, 4)
+    Bytes()
+    Bytes(1, 2, 3)
+    Bytes(1, 2, 4)
+    "Operator `+` is not defined for operand types `Bytes` and `List`. Left operand : Bytes(1, 2, 3) Right operand: List(1, 2, 4)"
+  }
+  ["subscript"] {
+    1
+    2
+    3
+    "Element index `3` is out of range `0`..`2`. Value: Bytes(1, 2, 3)"
+  }
+  ["all bytes"] {
+    Bytes(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255)
+  }
+}

pkl-core/src/test/files/LanguageSnippetTests/output/basic/read.pcf

@@ -22,7 +22,7 @@ examples {
         file1
         
         """
-      base64 = "ZmlsZTEK"
+      bytes = Bytes(102, 105, 108, 101, 49, 10)
     }
     "Cannot find resource `other.txt`."
     new {
@@ -31,7 +31,7 @@ examples {
         file1
         
         """
-      base64 = "ZmlsZTEK"
+      bytes = Bytes(102, 105, 108, 101, 49, 10)
     }
     null
   }
@@ -42,7 +42,7 @@ examples {
         resource
         
         """
-      base64 = "cmVzb3VyY2UK"
+      bytes = Bytes(114, 101, 115, 111, 117, 114, 99, 101, 10)
     }
     new {
       uri = "file:///$snippetsDir/input-helper/basic/read/resource.txt"
@@ -50,7 +50,7 @@ examples {
         resource
         
         """
-      base64 = "cmVzb3VyY2UK"
+      bytes = Bytes(114, 101, 115, 111, 117, 114, 99, 101, 10)
     }
   }
   ["read non-allowed resource"] {
@@ -64,7 +64,7 @@ examples {
         file1
         
         """
-      base64 = "ZmlsZTEK"
+      bytes = Bytes(102, 105, 108, 101, 49, 10)
     }
     new {
       uri = "file:///$snippetsDir/input/basic/globtest/file2.txt"
@@ -72,7 +72,7 @@ examples {
         file2
         
         """
-      base64 = "ZmlsZTIK"
+      bytes = Bytes(102, 105, 108, 101, 50, 10)
     }
   }
   ["read different resources with same relative resource URI"] {
@@ -82,7 +82,7 @@ examples {
         resource
         
         """
-      base64 = "cmVzb3VyY2UK"
+      bytes = Bytes(114, 101, 115, 111, 117, 114, 99, 101, 10)
     }
     new {
       uri = "file:///$snippetsDir/input-helper/basic/read/child/resource.txt"
@@ -90,7 +90,7 @@ examples {
         child resource
         
         """
-      base64 = "Y2hpbGQgcmVzb3VyY2UK"
+      bytes = Bytes(99, 104, 105, 108, 100, 32, 114, 101, 115, 111, 117, 114, 99, 101, 10)
     }
   }
 }

pkl-core/src/test/files/LanguageSnippetTests/output/basic/readGlob.pcf

@@ -4,7 +4,7 @@ examples {
       ["../../input-helper/globtest/module with [weird] ~!characters.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/module%20with%20%5Bweird%5D%20~!characters.pkl"
         text = ""
-        base64 = ""
+        bytes = Bytes()
       }
       ["../../input-helper/globtest/moduleA.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/moduleA.pkl"
@@ -12,7 +12,7 @@ examples {
           name = "moduleA"
           
           """
-        base64 = "bmFtZSA9ICJtb2R1bGVBIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 109, 111, 100, 117, 108, 101, 65, 34, 10)
       }
       ["../../input-helper/globtest/moduleB.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/moduleB.pkl"
@@ -20,7 +20,7 @@ examples {
           name = "moduleB"
           
           """
-        base64 = "bmFtZSA9ICJtb2R1bGVCIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 109, 111, 100, 117, 108, 101, 66, 34, 10)
       }
       ["../../input-helper/globtest/child/moduleC.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/child/moduleC.pkl"
@@ -28,7 +28,7 @@ examples {
           name = "child/moduleC"
           
           """
-        base64 = "bmFtZSA9ICJjaGlsZC9tb2R1bGVDIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 99, 104, 105, 108, 100, 47, 109, 111, 100, 117, 108, 101, 67, 34, 10)
       }
     }
     new {
@@ -38,7 +38,7 @@ examples {
           file1
           
           """
-        base64 = "ZmlsZTEK"
+        bytes = Bytes(102, 105, 108, 101, 49, 10)
       }
       ["globtest/file2.txt"] {
         uri = "file:///$snippetsDir/input/basic/globtest/file2.txt"
@@ -46,7 +46,7 @@ examples {
           file2
           
           """
-        base64 = "ZmlsZTIK"
+        bytes = Bytes(102, 105, 108, 101, 50, 10)
       }
     }
   }
@@ -55,22 +55,22 @@ examples {
       ["../../input-helper/globtest/module with [weird] ~!characters.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/module%20with%20%5Bweird%5D%20~!characters.pkl"
         text = "hi"
-        base64 = ""
+        bytes = Bytes()
       }
       ["../../input-helper/globtest/moduleA.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/moduleA.pkl"
         text = "hi"
-        base64 = "bmFtZSA9ICJtb2R1bGVBIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 109, 111, 100, 117, 108, 101, 65, 34, 10)
       }
       ["../../input-helper/globtest/moduleB.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/moduleB.pkl"
         text = "hi"
-        base64 = "bmFtZSA9ICJtb2R1bGVCIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 109, 111, 100, 117, 108, 101, 66, 34, 10)
       }
       ["../../input-helper/globtest/child/moduleC.pkl"] {
         uri = "file:///$snippetsDir/input-helper/globtest/child/moduleC.pkl"
         text = "hi"
-        base64 = "bmFtZSA9ICJjaGlsZC9tb2R1bGVDIgo="
+        bytes = Bytes(110, 97, 109, 101, 32, 61, 32, 34, 99, 104, 105, 108, 100, 47, 109, 111, 100, 117, 108, 101, 67, 34, 10)
       }
     }
   }
@@ -132,7 +132,7 @@ examples {
           favoriteFruit: Fruit
           
           """
-        base64 = "b3BlbiBtb2R1bGUgYmlyZHMuQmlyZAoKaW1wb3J0ICJAZnJ1aXRpZXMvRnJ1aXQucGtsIgoKbmFtZTogU3RyaW5nCgpmYXZvcml0ZUZydWl0OiBGcnVpdAo="
+        bytes = Bytes(111, 112, 101, 110, 32, 109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 66, 105, 114, 100, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 70, 114, 117, 105, 116, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 58, 32, 83, 116, 114, 105, 110, 103, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 58, 32, 70, 114, 117, 105, 116, 10)
       }
       ["package://localhost:0/birds@0.5.0#/allFruit.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/allFruit.pkl"
@@ -143,7 +143,7 @@ examples {
           fruitFiles = read*("@fruities/catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmFsbEZydWl0CgpmcnVpdCA9IGltcG9ydCooIkBmcnVpdGllcy9jYXRhbG9nLyoucGtsIikKZnJ1aXRGaWxlcyA9IHJlYWQqKCJAZnJ1aXRpZXMvY2F0YWxvZy8qLnBrbCIpCg=="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 97, 108, 108, 70, 114, 117, 105, 116, 10, 10, 102, 114, 117, 105, 116, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 102, 114, 117, 105, 116, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
       ["package://localhost:0/birds@0.5.0#/catalog.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog.pkl"
@@ -154,7 +154,7 @@ examples {
           catalogFiles = read*("catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmNhdGFsb2cKCmNhdGFsb2cgPSBpbXBvcnQqKCJjYXRhbG9nLyoucGtsIikKY2F0YWxvZ0ZpbGVzID0gcmVhZCooImNhdGFsb2cvKi5wa2wiKQo="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 99, 97, 116, 97, 108, 111, 103, 10, 10, 99, 97, 116, 97, 108, 111, 103, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 99, 97, 116, 97, 108, 111, 103, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
       ["package://localhost:0/birds@0.5.0#/catalog/Ostrich.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog/Ostrich.pkl"
@@ -168,7 +168,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -182,7 +182,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
       ["package://localhost:0/birds@0.5.0#/some/dir/Bird.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/some/dir/Bird.pkl"
@@ -196,7 +196,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi4iCgpuYW1lID0gIkJpcmQiCgpmYXZvcml0ZUZydWl0IHsKICBuYW1lID0gIkZydWl0Igp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 46, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 66, 105, 114, 100, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 70, 114, 117, 105, 116, 34, 10, 125, 10)
       }
     }
   }
@@ -208,7 +208,7 @@ examples {
           file1
           
           """
-        base64 = "ZmlsZTEK"
+        bytes = Bytes(102, 105, 108, 101, 49, 10)
       }
       ["globtest/file2.txt"] {
         uri = "file:///$snippetsDir/input/basic/globtest/file2.txt"
@@ -216,7 +216,7 @@ examples {
           file2
           
           """
-        base64 = "ZmlsZTIK"
+        bytes = Bytes(102, 105, 108, 101, 50, 10)
       }
     }
     new {
@@ -226,7 +226,7 @@ examples {
           file1
           
           """
-        base64 = "ZmlsZTEK"
+        bytes = Bytes(102, 105, 108, 101, 49, 10)
       }
     }
     new {
@@ -236,7 +236,7 @@ examples {
           file2
           
           """
-        base64 = "ZmlsZTIK"
+        bytes = Bytes(102, 105, 108, 101, 50, 10)
       }
     }
   }
@@ -248,7 +248,7 @@ examples {
           resource
           
           """
-        base64 = "cmVzb3VyY2UK"
+        bytes = Bytes(114, 101, 115, 111, 117, 114, 99, 101, 10)
       }
     }
     new {
@@ -258,7 +258,7 @@ examples {
           child resource
           
           """
-        base64 = "Y2hpbGQgcmVzb3VyY2UK"
+        bytes = Bytes(99, 104, 105, 108, 100, 32, 114, 101, 115, 111, 117, 114, 99, 101, 10)
       }
     }
   }

pkl-core/src/test/files/LanguageSnippetTests/output/errors/decodingException.err

@@ -0,0 +1,10 @@
+–– Pkl Error ––
+Invalid bytes for charset "UTF-8".
+
+x | res = Bytes(0xc0, 0xc1).decodeToString("UTF-8")
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at decodingException#res (file:///$snippetsDir/input/errors/decodingException.pkl)
+
+xxx | text = renderer.renderDocument(value)
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)

pkl-core/src/test/files/LanguageSnippetTests/output/errors/invalidBytes1.err

@@ -0,0 +1,15 @@
+–– Pkl Error ––
+Type constraint `isBetween(0, 255)` violated.
+Value: 65535
+
+xxx | typealias UInt8 = Int(isBetween(0, 255))
+                            ^^^^^^^^^^^^^^^^^
+at invalidBytes1#foo (pkl:base)
+
+x | foo = Bytes(0, 1, 2, 3, 0xffff)
+                            ^^^^^^
+at invalidBytes1#foo (file:///$snippetsDir/input/errors/invalidBytes1.pkl)
+
+xxx | text = renderer.renderDocument(value)
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)

pkl-core/src/test/files/LanguageSnippetTests/output/errors/invalidBytes2.err

@@ -0,0 +1,15 @@
+–– Pkl Error ––
+Type constraint `isBetween(0, 255)` violated.
+Value: 4095
+
+xxx | typealias UInt8 = Int(isBetween(0, 255))
+                            ^^^^^^^^^^^^^^^^^
+at invalidBytes2#res (pkl:base)
+
+x | res = Bytes(0, 1, 2, 3, num)
+                            ^^^
+at invalidBytes2#res (file:///$snippetsDir/input/errors/invalidBytes2.pkl)
+
+xxx | text = renderer.renderDocument(value)
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)

pkl-core/src/test/files/LanguageSnippetTests/output/errors/invalidBytes3.err

@@ -0,0 +1,15 @@
+–– Pkl Error ––
+Type constraint `isBetween(0, 255)` violated.
+Value: 65535
+
+xxx | typealias UInt8 = Int(isBetween(0, 255))
+                            ^^^^^^^^^^^^^^^^^
+at invalidBytes3#bytes (pkl:base)
+
+x | bytes = Bytes(0, 1, 2, 3, 0xffff)
+                              ^^^^^^
+at invalidBytes3#bytes (file:///$snippetsDir/input/errors/invalidBytes3.pkl)
+
+xxx | text = renderer.renderDocument(value)
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)

pkl-core/src/test/files/LanguageSnippetTests/output/errors/invalidBytes4.err

@@ -0,0 +1,15 @@
+–– Pkl Error ––
+Type constraint `isBetween(0, 255)` violated.
+Value: 65535
+
+xxx | typealias UInt8 = Int(isBetween(0, 255))
+                            ^^^^^^^^^^^^^^^^^
+at pkl.base#List.toBytes (pkl:base)
+
+x | res = List(1, 2, 3, 0xffff).toBytes()
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at invalidBytes4#res (file:///$snippetsDir/input/errors/invalidBytes4.pkl)
+
+xxx | text = renderer.renderDocument(value)
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)

pkl-core/src/test/files/LanguageSnippetTests/output/generators/elementGenerators.pcf

@@ -226,6 +226,13 @@ res11d {
   Pair(1, 2)
   Pair(2, 3)
 }
+res12a {
+  1
+  2
+  3
+  4
+}
+res12b {}
 valueForOverProperties {
   ["Foo!"] = "Foo!"
   [42] = 42

pkl-core/src/test/files/LanguageSnippetTests/output/generators/spreadSyntaxDynamic.pcf

@@ -37,6 +37,10 @@ examples {
       10
       20
       30
+      1
+      2
+      3
+      4
     }
   }
   ["explicit Dynamic type"] {
@@ -69,6 +73,10 @@ examples {
       10
       20
       30
+      1
+      2
+      3
+      4
     }
   }
   ["legacy syntax"] {
@@ -105,5 +113,11 @@ examples {
       20
       30
     }
+    new {
+      1
+      2
+      3
+      4
+    }
   }
 }

pkl-core/src/test/files/LanguageSnippetTests/output/generators/spreadSyntaxListing.pcf

@@ -103,3 +103,19 @@ res16 {
   0
 }
 res17 = 7
+res18 {
+  1
+  2
+  3
+  4
+}
+res19 {
+  0
+  1
+  2
+  3
+  4
+  0
+  0
+  0
+}

pkl-core/src/test/files/LanguageSnippetTests/output/generators/spreadSyntaxMapping.pcf

@@ -55,3 +55,4 @@ res17 {
     }
   }
 }
+res18 = "Cannot spread value of type `Bytes` into object of type `Mapping`. Value: Bytes(1, 2, 3, 4)"

pkl-core/src/test/files/LanguageSnippetTests/output/modules/invalidAmend6.err

@@ -7,6 +7,11 @@ at invalidAmend6#resource (file:///$snippetsDir/input/modules/invalidAmend6.pkl)
 
 Available properties:
 base64
+bytes
+md5
+sha1
+sha256
+sha256Int
 text
 uri
 

pkl-core/src/test/files/LanguageSnippetTests/output/packages/packages1.pcf

@@ -40,7 +40,7 @@ examples {
         favoriteFruit: Fruit
         
         """
-      base64 = "b3BlbiBtb2R1bGUgYmlyZHMuQmlyZAoKaW1wb3J0ICJAZnJ1aXRpZXMvRnJ1aXQucGtsIgoKbmFtZTogU3RyaW5nCgpmYXZvcml0ZUZydWl0OiBGcnVpdAo="
+      bytes = Bytes(111, 112, 101, 110, 32, 109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 66, 105, 114, 100, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 70, 114, 117, 105, 116, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 58, 32, 83, 116, 114, 105, 110, 103, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 58, 32, 70, 114, 117, 105, 116, 10)
     }
     new {
       uri = "package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -54,7 +54,7 @@ examples {
         favoriteFruit = apple
         
         """
-      base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+      bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
     }
     new {
       uri = "package://localhost:0/birds@0.5.0#/catalog/Ostrich.pkl"
@@ -68,7 +68,7 @@ examples {
         }
         
         """
-      base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+      bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
     }
   }
 }

pkl-core/src/test/files/LanguageSnippetTests/output/packages/packages2.pcf

@@ -52,7 +52,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -66,7 +66,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
     }
   }
@@ -84,7 +84,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["catalog/Swallow.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -98,7 +98,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
     }
   }
@@ -112,7 +112,7 @@ examples {
           name = "Apple"
           
           """
-        base64 = "YW1lbmRzICIuLi9GcnVpdC5wa2wiCgpuYW1lID0gIkFwcGxlIgo="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 70, 114, 117, 105, 116, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 65, 112, 112, 108, 101, 34, 10)
       }
     }
   }

pkl-core/src/test/files/LanguageSnippetTests/output/projects/project1/basic.pcf

@@ -44,7 +44,7 @@ examples {
         Swallow.pkl
         
         """
-      base64 = "T3N0cmljaC5wa2wKU3dhbGxvdy5wa2wK"
+      bytes = Bytes(79, 115, 116, 114, 105, 99, 104, 46, 112, 107, 108, 10, 83, 119, 97, 108, 108, 111, 119, 46, 112, 107, 108, 10)
     }
     new {
       uri = "projectpackage://localhost:0/birds@0.5.0#/"
@@ -56,7 +56,7 @@ examples {
         some
         
         """
-      base64 = "QmlyZC5wa2wKYWxsRnJ1aXQucGtsCmNhdGFsb2cKY2F0YWxvZy5wa2wKc29tZQo="
+      bytes = Bytes(66, 105, 114, 100, 46, 112, 107, 108, 10, 97, 108, 108, 70, 114, 117, 105, 116, 46, 112, 107, 108, 10, 99, 97, 116, 97, 108, 111, 103, 10, 99, 97, 116, 97, 108, 111, 103, 46, 112, 107, 108, 10, 115, 111, 109, 101, 10)
     }
   }
 }

pkl-core/src/test/files/LanguageSnippetTests/output/projects/project1/globbing.pcf

@@ -62,7 +62,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["@birds/catalog/Swallow.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -76,7 +76,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
     }
     new {
@@ -92,7 +92,7 @@ examples {
           favoriteFruit: Fruit
           
           """
-        base64 = "b3BlbiBtb2R1bGUgYmlyZHMuQmlyZAoKaW1wb3J0ICJAZnJ1aXRpZXMvRnJ1aXQucGtsIgoKbmFtZTogU3RyaW5nCgpmYXZvcml0ZUZydWl0OiBGcnVpdAo="
+        bytes = Bytes(111, 112, 101, 110, 32, 109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 66, 105, 114, 100, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 70, 114, 117, 105, 116, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 58, 32, 83, 116, 114, 105, 110, 103, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 58, 32, 70, 114, 117, 105, 116, 10)
       }
       ["@birds/allFruit.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/allFruit.pkl"
@@ -103,7 +103,7 @@ examples {
           fruitFiles = read*("@fruities/catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmFsbEZydWl0CgpmcnVpdCA9IGltcG9ydCooIkBmcnVpdGllcy9jYXRhbG9nLyoucGtsIikKZnJ1aXRGaWxlcyA9IHJlYWQqKCJAZnJ1aXRpZXMvY2F0YWxvZy8qLnBrbCIpCg=="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 97, 108, 108, 70, 114, 117, 105, 116, 10, 10, 102, 114, 117, 105, 116, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 102, 114, 117, 105, 116, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
       ["@birds/catalog.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog.pkl"
@@ -114,7 +114,7 @@ examples {
           catalogFiles = read*("catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmNhdGFsb2cKCmNhdGFsb2cgPSBpbXBvcnQqKCJjYXRhbG9nLyoucGtsIikKY2F0YWxvZ0ZpbGVzID0gcmVhZCooImNhdGFsb2cvKi5wa2wiKQo="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 99, 97, 116, 97, 108, 111, 103, 10, 10, 99, 97, 116, 97, 108, 111, 103, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 99, 97, 116, 97, 108, 111, 103, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
     }
     new {
@@ -130,7 +130,7 @@ examples {
           favoriteFruit: Fruit
           
           """
-        base64 = "b3BlbiBtb2R1bGUgYmlyZHMuQmlyZAoKaW1wb3J0ICJAZnJ1aXRpZXMvRnJ1aXQucGtsIgoKbmFtZTogU3RyaW5nCgpmYXZvcml0ZUZydWl0OiBGcnVpdAo="
+        bytes = Bytes(111, 112, 101, 110, 32, 109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 66, 105, 114, 100, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 70, 114, 117, 105, 116, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 58, 32, 83, 116, 114, 105, 110, 103, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 58, 32, 70, 114, 117, 105, 116, 10)
       }
       ["@birds/allFruit.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/allFruit.pkl"
@@ -141,7 +141,7 @@ examples {
           fruitFiles = read*("@fruities/catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmFsbEZydWl0CgpmcnVpdCA9IGltcG9ydCooIkBmcnVpdGllcy9jYXRhbG9nLyoucGtsIikKZnJ1aXRGaWxlcyA9IHJlYWQqKCJAZnJ1aXRpZXMvY2F0YWxvZy8qLnBrbCIpCg=="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 97, 108, 108, 70, 114, 117, 105, 116, 10, 10, 102, 114, 117, 105, 116, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 102, 114, 117, 105, 116, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
       ["@birds/catalog.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog.pkl"
@@ -152,7 +152,7 @@ examples {
           catalogFiles = read*("catalog/*.pkl")
           
           """
-        base64 = "bW9kdWxlIGJpcmRzLmNhdGFsb2cKCmNhdGFsb2cgPSBpbXBvcnQqKCJjYXRhbG9nLyoucGtsIikKY2F0YWxvZ0ZpbGVzID0gcmVhZCooImNhdGFsb2cvKi5wa2wiKQo="
+        bytes = Bytes(109, 111, 100, 117, 108, 101, 32, 98, 105, 114, 100, 115, 46, 99, 97, 116, 97, 108, 111, 103, 10, 10, 99, 97, 116, 97, 108, 111, 103, 32, 61, 32, 105, 109, 112, 111, 114, 116, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10, 99, 97, 116, 97, 108, 111, 103, 70, 105, 108, 101, 115, 32, 61, 32, 114, 101, 97, 100, 42, 40, 34, 99, 97, 116, 97, 108, 111, 103, 47, 42, 46, 112, 107, 108, 34, 41, 10)
       }
       ["@birds/catalog/Ostrich.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog/Ostrich.pkl"
@@ -166,7 +166,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["@birds/catalog/Swallow.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -180,7 +180,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
       ["@birds/some/dir/Bird.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/some/dir/Bird.pkl"
@@ -194,7 +194,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi4iCgpuYW1lID0gIkJpcmQiCgpmYXZvcml0ZUZydWl0IHsKICBuYW1lID0gIkZydWl0Igp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 46, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 66, 105, 114, 100, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 70, 114, 117, 105, 116, 34, 10, 125, 10)
       }
     }
   }
@@ -212,7 +212,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["catalog/Swallow.pkl"] {
         uri = "projectpackage://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -226,7 +226,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
     }
   }
@@ -244,7 +244,7 @@ examples {
           }
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCm5hbWUgPSAiT3N0cmljaCIKCmZhdm9yaXRlRnJ1aXQgewogIG5hbWUgPSAiT3JhbmdlIgp9Cg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 79, 115, 116, 114, 105, 99, 104, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 79, 114, 97, 110, 103, 101, 34, 10, 125, 10)
       }
       ["package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"] {
         uri = "package://localhost:0/birds@0.5.0#/catalog/Swallow.pkl"
@@ -258,7 +258,7 @@ examples {
           favoriteFruit = apple
           
           """
-        base64 = "YW1lbmRzICIuLi9CaXJkLnBrbCIKCmltcG9ydCAiQGZydWl0aWVzL2NhdGFsb2cvYXBwbGUucGtsIgoKbmFtZSA9ICJTd2FsbG93IgoKZmF2b3JpdGVGcnVpdCA9IGFwcGxlCg=="
+        bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 46, 46, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 105, 109, 112, 111, 114, 116, 32, 34, 64, 102, 114, 117, 105, 116, 105, 101, 115, 47, 99, 97, 116, 97, 108, 111, 103, 47, 97, 112, 112, 108, 101, 46, 112, 107, 108, 34, 10, 10, 110, 97, 109, 101, 32, 61, 32, 34, 83, 119, 97, 108, 108, 111, 119, 34, 10, 10, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 61, 32, 97, 112, 112, 108, 101, 10)
       }
     }
   }

pkl-core/src/test/files/LanguageSnippetTests/output/projects/project1/localProjectRead.pcf

@@ -29,7 +29,7 @@ res2 {
       }
       
       """
-    base64 = "YW1lbmRzICJwa2w6UHJvamVjdCIKCnBhY2thZ2UgewogIG5hbWUgPSAicHJvamVjdDIiCiAgYmFzZVVyaSA9ICJwYWNrYWdlOi8vbG9jYWxob3N0OjAvcHJvamVjdDIiCiAgdmVyc2lvbiA9ICIxLjAuMCIKICBwYWNrYWdlWmlwVXJsID0gImh0dHBzOi8vbG9jYWxob3N0OjAvcHJvamVjdDIvcHJvamVjdDItXCh2ZXJzaW9uKS56aXAiCn0KCmRlcGVuZGVuY2llcyB7CiAgWyJidXJkcyJdIHsKICAgIHVyaSA9ICJwYWNrYWdlOi8vbG9jYWxob3N0OjAvYmlyZHNAMC41LjAiCiAgfQp9Cg=="
+    bytes = Bytes(97, 109, 101, 110, 100, 115, 32, 34, 112, 107, 108, 58, 80, 114, 111, 106, 101, 99, 116, 34, 10, 10, 112, 97, 99, 107, 97, 103, 101, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 112, 114, 111, 106, 101, 99, 116, 50, 34, 10, 32, 32, 98, 97, 115, 101, 85, 114, 105, 32, 61, 32, 34, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 112, 114, 111, 106, 101, 99, 116, 50, 34, 10, 32, 32, 118, 101, 114, 115, 105, 111, 110, 32, 61, 32, 34, 49, 46, 48, 46, 48, 34, 10, 32, 32, 112, 97, 99, 107, 97, 103, 101, 90, 105, 112, 85, 114, 108, 32, 61, 32, 34, 104, 116, 116, 112, 115, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 112, 114, 111, 106, 101, 99, 116, 50, 47, 112, 114, 111, 106, 101, 99, 116, 50, 45, 92, 40, 118, 101, 114, 115, 105, 111, 110, 41, 46, 122, 105, 112, 34, 10, 125, 10, 10, 100, 101, 112, 101, 110, 100, 101, 110, 99, 105, 101, 115, 32, 123, 10, 32, 32, 91, 34, 98, 117, 114, 100, 115, 34, 93, 32, 123, 10, 32, 32, 32, 32, 117, 114, 105, 32, 61, 32, 34, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 98, 105, 114, 100, 115, 64, 48, 46, 53, 46, 48, 34, 10, 32, 32, 125, 10, 125, 10)
   }
   ["@project2/PklProject.deps.json"] {
     uri = "file:/$snippetsDir/input/projects/project2/PklProject.deps.json"
@@ -55,7 +55,7 @@ res2 {
       }
       
       """
-    base64 = "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"
+    bytes = Bytes(123, 10, 32, 32, 34, 115, 99, 104, 101, 109, 97, 86, 101, 114, 115, 105, 111, 110, 34, 58, 32, 49, 44, 10, 32, 32, 34, 114, 101, 115, 111, 108, 118, 101, 100, 68, 101, 112, 101, 110, 100, 101, 110, 99, 105, 101, 115, 34, 58, 32, 123, 10, 32, 32, 32, 32, 34, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 98, 105, 114, 100, 115, 64, 48, 34, 58, 32, 123, 10, 32, 32, 32, 32, 32, 32, 34, 116, 121, 112, 101, 34, 58, 32, 34, 114, 101, 109, 111, 116, 101, 34, 44, 10, 32, 32, 32, 32, 32, 32, 34, 117, 114, 105, 34, 58, 32, 34, 112, 114, 111, 106, 101, 99, 116, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 98, 105, 114, 100, 115, 64, 48, 46, 53, 46, 48, 34, 44, 10, 32, 32, 32, 32, 32, 32, 34, 99, 104, 101, 99, 107, 115, 117, 109, 115, 34, 58, 32, 123, 10, 32, 32, 32, 32, 32, 32, 32, 32, 34, 115, 104, 97, 50, 53, 54, 34, 58, 32, 34, 36, 115, 107, 105, 112, 67, 104, 101, 99, 107, 115, 117, 109, 86, 101, 114, 105, 102, 105, 99, 97, 116, 105, 111, 110, 34, 10, 32, 32, 32, 32, 32, 32, 125, 10, 32, 32, 32, 32, 125, 44, 10, 32, 32, 32, 32, 34, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 102, 114, 117, 105, 116, 64, 49, 34, 58, 32, 123, 10, 32, 32, 32, 32, 32, 32, 34, 116, 121, 112, 101, 34, 58, 32, 34, 114, 101, 109, 111, 116, 101, 34, 44, 10, 32, 32, 32, 32, 32, 32, 34, 117, 114, 105, 34, 58, 32, 34, 112, 114, 111, 106, 101, 99, 116, 112, 97, 99, 107, 97, 103, 101, 58, 47, 47, 108, 111, 99, 97, 108, 104, 111, 115, 116, 58, 48, 47, 102, 114, 117, 105, 116, 64, 49, 46, 49, 46, 48, 34, 44, 10, 32, 32, 32, 32, 32, 32, 34, 99, 104, 101, 99, 107, 115, 117, 109, 115, 34, 58, 32, 123, 10, 32, 32, 32, 32, 32, 32, 32, 32, 34, 115, 104, 97, 50, 53, 54, 34, 58, 32, 34, 36, 115, 107, 105, 112, 67, 104, 101, 99, 107, 115, 117, 109, 86, 101, 114, 105, 102, 105, 99, 97, 116, 105, 111, 110, 34, 10, 32, 32, 32, 32, 32, 32, 125, 10, 32, 32, 32, 32, 125, 10, 32, 32, 125, 10, 125, 10)
   }
   ["@project2/penguin.pkl"] {
     uri = "file:/$snippetsDir/input/projects/project2/penguin.pkl"
@@ -70,6 +70,6 @@ res2 {
       }
       
       """
-    base64 = "aW1wb3J0ICJAYnVyZHMvQmlyZC5wa2wiCgpiaXJkOiBCaXJkID0gbmV3IHsKICBuYW1lID0gIlBlbmd1aW4iCiAgZmF2b3JpdGVGcnVpdCB7CiAgICBuYW1lID0gIkljZSBGcnVpdCIKICB9Cn0K"
+    bytes = Bytes(105, 109, 112, 111, 114, 116, 32, 34, 64, 98, 117, 114, 100, 115, 47, 66, 105, 114, 100, 46, 112, 107, 108, 34, 10, 10, 98, 105, 114, 100, 58, 32, 66, 105, 114, 100, 32, 61, 32, 110, 101, 119, 32, 123, 10, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 80, 101, 110, 103, 117, 105, 110, 34, 10, 32, 32, 102, 97, 118, 111, 114, 105, 116, 101, 70, 114, 117, 105, 116, 32, 123, 10, 32, 32, 32, 32, 110, 97, 109, 101, 32, 61, 32, 34, 73, 99, 101, 32, 70, 114, 117, 105, 116, 34, 10, 32, 32, 125, 10, 125, 10)
   }
 }

pkl-core/src/test/kotlin/org/pkl/core/EvaluateMultipleFileOutputTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,9 +49,13 @@ class EvaluateMultipleFileOutputTest {
     val output = evaluator.evaluateOutputFiles(text(program))
     assertThat(output.keys).isEqualTo(setOf("foo.yml", "bar.yml", "bar/biz.yml", "bar/../bark.yml"))
     assertThat(output["foo.yml"]?.text).isEqualTo("foo: foo text")
+    assertThat(output["foo.yml"]?.bytes).isEqualTo("foo: foo text".toByteArray())
     assertThat(output["bar.yml"]?.text).isEqualTo("bar: bar text")
+    assertThat(output["bar.yml"]?.bytes).isEqualTo("bar: bar text".toByteArray())
     assertThat(output["bar/biz.yml"]?.text).isEqualTo("biz: bar biz")
+    assertThat(output["bar/biz.yml"]?.bytes).isEqualTo("biz: bar biz".toByteArray())
     assertThat(output["bar/../bark.yml"]?.text).isEqualTo("bark: bark bark")
+    assertThat(output["bar/../bark.yml"]?.bytes).isEqualTo("bark: bark bark".toByteArray())
   }
 
   @Test

pkl-core/src/test/kotlin/org/pkl/core/runtime/VmValueRendererTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2025 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -32,4 +32,26 @@ class VmValueRendererTest {
     val none = VmNull.withDefault("default")
     assertThat(renderer.render(none)).isEqualTo("null")
   }
+
+  @Test
+  fun `render bytes`() {
+    val bytes = VmBytes((-128..127).map { it.toByte() }.toByteArray())
+    assertThat(renderer.render(bytes))
+      .isEqualTo("Bytes(128, 129, 130, 131, 132, 133, 134, 135, ... <total size: 256.b>)")
+  }
+
+  @Test
+  fun `render bytes - precisions`() {
+    val oneKbExactly = VmBytes(ByteArray(1000))
+    assertThat(renderer.render(oneKbExactly))
+      .isEqualTo("Bytes(0, 0, 0, 0, 0, 0, 0, 0, ... <total size: 1.kb>)")
+
+    val over1Kb = VmBytes(ByteArray(123467))
+    assertThat(renderer.render(over1Kb))
+      .isEqualTo("Bytes(0, 0, 0, 0, 0, 0, 0, 0, ... <total size: 123.47.kb>)")
+
+    val oneTenthPrecision = VmBytes(ByteArray(1100))
+    assertThat(renderer.render(oneTenthPrecision))
+      .isEqualTo("Bytes(0, 0, 0, 0, 0, 0, 0, 0, ... <total size: 1.1.kb>)")
+  }
 }