Run the desktop's model layer in the browser (#557)

2026-08-16 16:42:01 +02:00 · 2026-08-16 07:34:48 -07:00
parent 32e92d484b
commit 6f91f76064
36 changed files with 3266 additions and 24 deletions
@@ -2,6 +2,18 @@
 # It is not intended for manual editing.
 version = 4

+[[package]]
+name = "accessory"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc86a613208ca7d144ca24f6ec49c5cdfa5c05a46f2f7ab5880ff99371f165de"
+dependencies = [
+ "macroific 3.0.1",
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "adler2"
 version = "2.0.0"
@@ -1375,6 +1387,16 @@ dependencies = [
 "windows-sys 0.61.2",
 ]

+[[package]]
+name = "console_error_panic_hook"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a06aeb73f470f66dcdbf7223caeebb85984942f22f1adb2a088cf9668146bbbc"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "const-random"
 version = "0.1.18"
@@ -1859,6 +1881,20 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "da692b8d1080ea3045efaab14434d40468c3d8657e42abddfffca87b428f4c1b"

+[[package]]
+name = "delegate-display"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54e3a499943fd5180aeffcb708164ffb22125ceeccb05491b5297981d37d6249"
+dependencies = [
+ "impartial-ord",
+ "itoa",
+ "macroific 3.0.1",
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "deranged"
 version = "0.5.5"
@@ -2350,6 +2386,18 @@ dependencies = [
 "regex-syntax 0.8.5",
 ]

+[[package]]
+name = "fancy_constructor"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a8211ab12c36b63c269e17873331dc1da196a3edb7a5c79015677ef972da34a"
+dependencies = [
+ "macroific 3.0.1",
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "fast-glob"
 version = "1.0.0"
@@ -3491,6 +3539,17 @@ dependencies = [
 "tiff",
 ]

+[[package]]
+name = "impartial-ord"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc680e03d1a08bdc1c01b60e0c39723430ced63d8cabd93cee0449b6ba916a25"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "include_dir"
 version = "0.7.4"
@@ -3510,6 +3569,40 @@ dependencies = [
 "quote",
 ]

+[[package]]
+name = "indexed_db_futures"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69ff41758cbd104e91033bb53bc449bec7eea65652960c81eddf3fc146ecea19"
+dependencies = [
+ "accessory",
+ "cfg-if",
+ "delegate-display",
+ "derive_more 2.1.1",
+ "fancy_constructor",
+ "indexed_db_futures_macros_internal",
+ "js-sys",
+ "sealed 0.6.0",
+ "smallvec",
+ "thiserror 2.0.17",
+ "tokio",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
+]
+
+[[package]]
+name = "indexed_db_futures_macros_internal"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caeba94923b68f254abef921cea7e7698bf4675fdd89d7c58bf1ed885b49a27d"
+dependencies = [
+ "macroific 2.0.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.101",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.3"
@@ -4092,6 +4185,102 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"

+[[package]]
+name = "macroific"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89f276537b4b8f981bf1c13d79470980f71134b7bdcc5e6e911e910e556b0285"
+dependencies = [
+ "macroific_attr_parse 2.0.0",
+ "macroific_core 2.0.0",
+ "macroific_macro 2.0.0",
+]
+
+[[package]]
+name = "macroific"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c437abb3bf40939b00d1dff858ed2050d948bc230dee39546ed16795fcf10ec2"
+dependencies = [
+ "macroific_attr_parse 3.0.1",
+ "macroific_core 3.0.1",
+ "macroific_macro 3.0.1",
+]
+
+[[package]]
+name = "macroific_attr_parse"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ad4023761b45fcd36abed8fb7ae6a80456b0a38102d55e89a57d9a594a236be9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "sealed 0.6.0",
+ "syn 2.0.101",
+]
+
+[[package]]
+name = "macroific_attr_parse"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aeb7a82ec1aa16094da719be18615d79cb2574b037358e4e6c6d96eedcff3a93"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "sealed 0.7.0",
+ "syn 3.0.3",
+]
+
+[[package]]
+name = "macroific_core"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a7594d3c14916fa55bef7e9d18c5daa9ed410dd37504251e4b75bbdeec33e3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "sealed 0.6.0",
+ "syn 2.0.101",
+]
+
+[[package]]
+name = "macroific_core"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "26c8e789484d2fa216eee9d5e0565ba80ccda389bcf0e111143a7b8f4792336e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "sealed 0.7.0",
+ "syn 3.0.3",
+]
+
+[[package]]
+name = "macroific_macro"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4da6f2ed796261b0a74e2b52b42c693bb6dee1effba3a482c49592659f824b3b"
+dependencies = [
+ "macroific_attr_parse 2.0.0",
+ "macroific_core 2.0.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.101",
+]
+
+[[package]]
+name = "macroific_macro"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e30d63cb102648965753f0d47a6ab171b1cbb1fb5c363f4784ea986782fc7b77"
+dependencies = [
+ "macroific_attr_parse 3.0.1",
+ "macroific_core 3.0.1",
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "malloc_buf"
 version = "0.0.6"
@@ -7456,6 +7645,28 @@ version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"

+[[package]]
+name = "sealed"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22f968c5ea23d555e670b449c1c5e7b2fc399fdaec1d304a17cd48e288abc107"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.101",
+]
+
+[[package]]
+name = "sealed"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b68e2ea526d9fb32f23ca8894fb5da9e743f34c2f41701f0501dc8a25c4b343"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
 [[package]]
 name = "security-framework"
 version = "2.11.1"
@@ -8037,6 +8248,22 @@ dependencies = [
 "wasm-bindgen",
 ]

+[[package]]
+name = "sqlite-wasm-vfs"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f7a5c9ac229421d577bb5a9bb59048838509958b218dd4e0b3c1214a87c361e"
+dependencies = [
+ "indexed_db_futures",
+ "js-sys",
+ "rsqlite-vfs",
+ "thiserror 2.0.17",
+ "tokio",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
+]
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.0"
@@ -8171,6 +8398,17 @@ dependencies = [
 "unicode-ident",
 ]

+[[package]]
+name = "syn"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53e9bae58849f64dfa4f5d5ae372c8341f7305f82a3868709269343628b659a3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "sync_wrapper"
 version = "1.0.2"
@@ -11473,6 +11711,23 @@ dependencies = [
 "yasna",
 ]

+[[package]]
+name = "yaak-web"
+version = "0.1.0"
+dependencies = [
+ "console_error_panic_hook",
+ "js-sys",
+ "log 0.4.29",
+ "serde",
+ "serde-wasm-bindgen",
+ "serde_json",
+ "sqlite-wasm-rs",
+ "sqlite-wasm-vfs",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "yaak-models",
+]
+
 [[package]]
 name = "yaak-window"
 version = "0.1.0"
@@ -20,6 +20,7 @@ members = [
  "crates/yaak-templates",
  "crates/yaak-tls",
  "crates/yaak-ws",
+  "crates/yaak-web",
  "crates/yaak-api",
  "crates/yaak-proxy",
  # Proxy-specific crates
@@ -44,6 +44,25 @@ After bootstrapping, start the app in development mode:
 npm start
 ```

+## Run the App in a Browser
+
+The client can also run as a plain web page, with no Tauri and no local process
+behind it. Set `YAAK_TARGET=web` and start the frontend on its own:
+
+```shell
+YAAK_TARGET=web npm run dev --workspace @yaakapp/yaak-client
+```
+
+That flag picks the browser host in `packages/platform/src/web/`, which answers
+commands from an IndexedDB database the page owns instead of from the Rust
+engine. Data persists across reloads and is shared between tabs on the same
+origin. Sending HTTP is not available yet — the Send button reports that and
+everything else about the request is still saved. `packages/platform/src/web/README.md`
+lists which commands the browser host implements and which it declines.
+
+Desktop builds are unaffected: without the flag the platform package installs
+the Tauri host exactly as before.
+
 ## SQLite Migrations

 New migrations can be created from the `src-tauri/` directory:
@@ -1,3 +1,4 @@
+import { platform } from "@yaakapp-internal/platform";
 import type { SettingsTab } from "../components/Settings/Settings";
 import { activeWorkspaceIdAtom } from "../hooks/useActiveWorkspace";
 import { createFastMutation } from "../hooks/useFastMutation";
@@ -14,11 +15,19 @@ export const openSettings = createFastMutation<void, string, SettingsTabWithSubt
    const workspaceId = jotaiStore.get(activeWorkspaceIdAtom);
    if (workspaceId == null) return;

-    const location = router.buildLocation({
-      to: "/workspaces/$workspaceId/settings",
-      params: { workspaceId },
-      search: { tab: (tab ?? undefined) as SettingsTab | undefined },
-    });
+    const to = "/workspaces/$workspaceId/settings" as const;
+    const params = { workspaceId };
+    const search = { tab: (tab ?? undefined) as SettingsTab | undefined };
+
+    // Settings is its own window where the host has windows to give. Where it
+    // doesn't — a browser tab — the same route opens in place, which is the
+    // whole difference: it is already a route, not a separate app.
+    if (!platform.capabilities.multiWindow) {
+      await router.navigate({ to, params, search });
+      return;
+    }
+
+    const location = router.buildLocation({ to, params, search });

    await rpc("cmd_new_child_window", {
      url: location.href,
@@ -1,3 +1,4 @@
+import { platform } from "@yaakapp-internal/platform";
 import { createFastMutation } from "../hooks/useFastMutation";
 import { getRecentCookieJars } from "../hooks/useRecentCookieJars";
 import { getRecentEnvironments } from "../hooks/useRecentEnvironments";
@@ -24,7 +25,9 @@ export const switchWorkspace = createFastMutation<
      request_id: requestId,
    };

-    if (inNewWindow) {
+    // A host without windows opens the workspace here instead. Refusing would
+    // strand the user on the workspace they were trying to leave.
+    if (inNewWindow && platform.capabilities.multiWindow) {
      const location = router.buildLocation({
        to: "/workspaces/$workspaceId",
        params: { workspaceId },
@@ -17,9 +17,37 @@ const standardFontsDir = normalizePath(
  path.join(path.dirname(require.resolve("pdfjs-dist/package.json")), "standard_fonts"),
 );

+/**
+ * Which host the platform package installs. `web` builds Yaak to run in a plain
+ * browser tab, with its own IndexedDB store instead of the Rust engine; anything
+ * else builds the desktop app exactly as before.
+ */
+const yaakTarget = process.env.YAAK_TARGET === "web" ? "web" : "desktop";
+
 // https://vitejs.dev/config/
 export default defineConfig(async () => {
  return {
+    resolve: {
+      alias:
+        yaakTarget === "web"
+          ? {
+              // Resolve the platform package to its browser entry, so a web
+              // build never pulls `@tauri-apps/*` into the graph at all. A
+              // build-time branch inside the package would not manage that:
+              // the dead branch folds away, but the imports it guarded stay.
+              "@yaakapp-internal/platform": path.resolve(
+                import.meta.dirname,
+                "../../packages/platform/src/index.web.ts",
+              ),
+            }
+          : {},
+    },
+    // The browser host runs the model layer in a worker; that bundle needs the
+    // same wasm and top-level-await handling as the main one.
+    worker: {
+      format: "es" as const,
+      plugins: () => [wasm(), topLevelAwait()],
+    },
    plugins: [
      wasm(),
      tanstackRouter({
@@ -147,7 +147,7 @@ pub(crate) fn models_upsert<R: Runtime>(
    let db = window.db();
    let blobs = window.blob_manager();
    let source = &UpdateSource::from_window_label(window.label());
-    yaak::models_ops::upsert_model(&db, &blobs, model, source)
+    yaak_models::models_ops::upsert_model(&db, &blobs, model, source)
 }

 // Async so cascading deletes (e.g. a workspace with thousands of requests) run on a
@@ -163,7 +163,7 @@ pub(crate) async fn models_delete<R: Runtime>(
        // Use transaction for deletions because it might recurse
        window.with_tx(|tx| {
            let source = &UpdateSource::from_window_label(window.label());
-            yaak::models_ops::delete_model(tx, &blobs, model, source)
+            yaak_models::models_ops::delete_model(tx, &blobs, model, source)
        })
    })
    .await
@@ -178,7 +178,7 @@ pub(crate) fn models_duplicate<R: Runtime>(
    // Use transaction for duplications because it might recurse
    window.with_tx(|tx| {
        let source = &UpdateSource::from_window_label(window.label());
-        yaak::models_ops::duplicate_model(tx, &model_type, &model_id, source)
+        yaak_models::models_ops::duplicate_model(tx, &model_type, &model_id, source)
    })
 }

@@ -14,6 +14,7 @@ mod connection_or_tx;
 pub mod error;
 pub mod migrate;
 pub mod models;
+pub mod models_ops;
 pub mod queries;
 pub mod query_manager;
 pub mod render;
@@ -24,6 +25,7 @@ fn init_connection(conn: &rusqlite::Connection) -> rusqlite::Result<()> {
    conn.busy_timeout(std::time::Duration::from_millis(5000))
 }

+#[cfg(not(target_arch = "wasm32"))]
 fn init_file_connection(conn: &rusqlite::Connection) -> rusqlite::Result<()> {
    conn.pragma_update(None, "journal_mode", "WAL")?;
    conn.pragma_update(None, "synchronous", "NORMAL")?;
@@ -7,12 +7,12 @@
 //! `UpdateSource` identifying who is writing; nothing here knows whether the
 //! caller is a desktop window or an HTTP request.

-use yaak_models::blob_manager::BlobManager;
-use yaak_models::client_db::ClientDb;
-use yaak_models::error::Error::GenericError;
-use yaak_models::error::Result;
-use yaak_models::models::AnyModel;
-use yaak_models::util::UpdateSource;
+use crate::blob_manager::BlobManager;
+use crate::client_db::ClientDb;
+use crate::error::Error::GenericError;
+use crate::error::Result;
+use crate::models::AnyModel;
+use crate::util::UpdateSource;

 pub fn upsert_model(
    db: &ClientDb,
@@ -0,0 +1,37 @@
+[package]
+name = "yaak-web"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+# The desktop's model layer, compiled for a browser tab. See src/lib.rs.
+#
+# Building needs a clang with a WebAssembly backend: sqlite-wasm-rs compiles
+# sqlite3.c to wasm at build time, and Apple's clang cannot target it. See
+# build-wasm.cjs, which points cc at Homebrew LLVM when it is present.
+
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = false # Matches yaak-templates; wasm-opt has caused errors in CI
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+# The whole crate is `#![cfg(target_arch = "wasm32")]`: on a native target it
+# is empty, so a workspace-wide `cargo test` neither builds SQLite's wasm shim
+# for the host (which fails) nor links a browser-only runtime. Everything that
+# only exists for wasm is a target-scoped dependency for the same reason.
+
+[dependencies]
+log = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+yaak-models = { workspace = true }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+console_error_panic_hook = "0.1"
+js-sys = "0.3"
+serde-wasm-bindgen = "0.6.5"
+sqlite-wasm-rs = "0.5"
+sqlite-wasm-vfs = "0.2"
+wasm-bindgen = "0.2.100"
+wasm-bindgen-futures = "0.4"
@@ -0,0 +1,79 @@
+const { execSync, spawnSync } = require("node:child_process");
+const fs = require("node:fs");
+const os = require("node:os");
+const path = require("node:path");
+
+// Same shape as crates/yaak-templates/build-wasm.cjs, plus one wrinkle: this
+// crate links SQLite, and sqlite-wasm-rs compiles sqlite3.c to wasm at build
+// time. That needs a C compiler with a WebAssembly backend, which Apple's
+// clang is not. So the build looks for one, and when it finds none it keeps
+// the committed pkg/ and says so — desktop developers never need this crate
+// rebuilt, and failing their `npm run bootstrap` over it would be wrong.
+
+if (process.env.SKIP_WASM_BUILD === "1") {
+  console.log("Skipping wasm-pack build (SKIP_WASM_BUILD=1)");
+  return;
+}
+
+/** A clang that can emit wasm32, or null. */
+function findWasmClang() {
+  const candidates = [
+    process.env.CC_wasm32_unknown_unknown,
+    "/opt/homebrew/opt/llvm/bin/clang", // Homebrew LLVM, Apple Silicon
+    "/usr/local/opt/llvm/bin/clang", // Homebrew LLVM, Intel
+    "clang", // Linux distros' clang usually has the backend built in
+  ].filter(Boolean);
+
+  for (const clang of candidates) {
+    const probe = spawnSync(clang, ["--print-targets"], { encoding: "utf8" });
+    if (probe.status === 0 && /\bwasm32\b/.test(probe.stdout)) return clang;
+  }
+  return null;
+}
+
+const clang = findWasmClang();
+if (clang == null) {
+  console.log(
+    [
+      "yaak-web: no C compiler with a WebAssembly backend found; keeping the committed pkg/.",
+      "  To rebuild: install LLVM (macOS: `brew install llvm`) or point CC_wasm32_unknown_unknown at one.",
+    ].join("\n"),
+  );
+  return;
+}
+
+// llvm-ar lives next to clang in every LLVM distribution
+const ar = path.join(path.dirname(clang), "llvm-ar");
+
+// Remap machine-specific paths that rustc embeds into the binary (panic
+// location strings), so builds are reproducible across machines
+const sysroot = execSync("rustc --print sysroot").toString().trim();
+const cargoHome = process.env.CARGO_HOME ?? path.join(os.homedir(), ".cargo");
+
+execSync("wasm-pack build --target bundler", {
+  stdio: "inherit",
+  cwd: __dirname,
+  env: {
+    ...process.env,
+    CC_wasm32_unknown_unknown: clang,
+    AR_wasm32_unknown_unknown: fs.existsSync(ar) ? ar : (process.env.AR_wasm32_unknown_unknown ?? ""),
+    RUSTFLAGS: `--remap-path-prefix=${cargoHome}=/cargo --remap-path-prefix=${sysroot}=/rustc`,
+  },
+});
+
+// Rewrite the generated entry to use Vite's ?init import style instead of
+// the ES Module Integration style that wasm-pack generates, which Vite/rolldown
+// does not support in production builds.
+const entry = path.join(__dirname, "pkg", "yaak_web.js");
+fs.writeFileSync(
+  entry,
+  [
+    'import init from "./yaak_web_bg.wasm?init";',
+    'export * from "./yaak_web_bg.js";',
+    'import * as bg from "./yaak_web_bg.js";',
+    'const instance = await init({ "./yaak_web_bg.js": bg });',
+    "bg.__wbg_set_wasm(instance.exports);",
+    "instance.exports.__wbindgen_start();",
+    "",
+  ].join("\n"),
+);
@@ -0,0 +1,6 @@
+// The desktop's model layer, compiled to wasm for the browser. See src/lib.rs.
+//
+// This is loaded by the SharedWorker in packages/platform/src/web/worker.ts and
+// nowhere else: it owns a SQLite database, and there must be exactly one of it
+// per origin.
+export { blob_delete, blob_get, blob_put, boot, rpc } from "./pkg";
@@ -0,0 +1,15 @@
+{
+  "name": "@yaakapp-internal/web",
+  "version": "1.0.0",
+  "private": true,
+  "main": "index.ts",
+  "scripts": {
+    "bootstrap": "npm run build",
+    "build": "run-s build:*",
+    "build:pack": "node build-wasm.cjs",
+    "build:clean": "rimraf ./pkg/.gitignore"
+  },
+  "devDependencies": {
+    "rimraf": "^6.1.2"
+  }
+}
@@ -0,0 +1,17 @@
+{
+  "name": "yaak-web",
+  "type": "module",
+  "version": "0.1.0",
+  "files": [
+    "yaak_web_bg.wasm",
+    "yaak_web.js",
+    "yaak_web_bg.js",
+    "yaak_web.d.ts"
+  ],
+  "main": "yaak_web.js",
+  "types": "yaak_web.d.ts",
+  "sideEffects": [
+    "./yaak_web.js",
+    "./snippets/*"
+  ]
+}
@@ -0,0 +1,36 @@
+/* tslint:disable */
+/* eslint-disable */
+
+export function blob_delete(id: string): void;
+
+/**
+ * The bytes stored under an id, or none. Ids are the desktop's: a response's
+ * own id for its body, `{responseId}.request` for the request that produced
+ * it. Bytes cross to JS as a `Uint8Array` rather than through JSON.
+ */
+export function blob_get(id: string): Uint8Array | undefined;
+
+/**
+ * Store bytes under an id, replacing anything already there. Chunked the way
+ * the desktop chunks, so a body written here reads back on a desktop that
+ * imports the database, and vice versa.
+ */
+export function blob_put(id: string, bytes: Uint8Array): void;
+
+/**
+ * Register the IndexedDB-backed VFS and open the database.
+ *
+ * Migrations run inside `init_standalone`, exactly as they do for the CLI.
+ * Safe to call more than once; later calls are no-ops.
+ */
+export function boot(): Promise<void>;
+
+/**
+ * Run one command as `label` (the calling tab's identity, which stands in for
+ * the desktop's window label on every write it makes).
+ *
+ * The payload shapes match the `Cmd*Req` types in `yaak-rpc-schema` — that
+ * crate itself pulls the git, gRPC and plugin crates for their response types
+ * and cannot come to wasm, so the handful needed here are declared locally.
+ */
+export function rpc(cmd: string, payload: any, label: string): any;
@@ -0,0 +1,6 @@
+import init from "./yaak_web_bg.wasm?init";
+export * from "./yaak_web_bg.js";
+import * as bg from "./yaak_web_bg.js";
+const instance = await init({ "./yaak_web_bg.js": bg });
+bg.__wbg_set_wasm(instance.exports);
+instance.exports.__wbindgen_start();
@@ -0,0 +1,975 @@
+/**
+ * @param {string} id
+ */
+export function blob_delete(id) {
+    const ptr0 = passStringToWasm0(id, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len0 = WASM_VECTOR_LEN;
+    const ret = wasm.blob_delete(ptr0, len0);
+    if (ret[1]) {
+        throw takeFromExternrefTable0(ret[0]);
+    }
+}
+
+/**
+ * The bytes stored under an id, or none. Ids are the desktop's: a response's
+ * own id for its body, `{responseId}.request` for the request that produced
+ * it. Bytes cross to JS as a `Uint8Array` rather than through JSON.
+ * @param {string} id
+ * @returns {Uint8Array | undefined}
+ */
+export function blob_get(id) {
+    const ptr0 = passStringToWasm0(id, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len0 = WASM_VECTOR_LEN;
+    const ret = wasm.blob_get(ptr0, len0);
+    if (ret[3]) {
+        throw takeFromExternrefTable0(ret[2]);
+    }
+    let v2;
+    if (ret[0] !== 0) {
+        v2 = getArrayU8FromWasm0(ret[0], ret[1]).slice();
+        wasm.__wbindgen_free(ret[0], ret[1] * 1, 1);
+    }
+    return v2;
+}
+
+/**
+ * Store bytes under an id, replacing anything already there. Chunked the way
+ * the desktop chunks, so a body written here reads back on a desktop that
+ * imports the database, and vice versa.
+ * @param {string} id
+ * @param {Uint8Array} bytes
+ */
+export function blob_put(id, bytes) {
+    const ptr0 = passStringToWasm0(id, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len0 = WASM_VECTOR_LEN;
+    const ptr1 = passArray8ToWasm0(bytes, wasm.__wbindgen_malloc);
+    const len1 = WASM_VECTOR_LEN;
+    const ret = wasm.blob_put(ptr0, len0, ptr1, len1);
+    if (ret[1]) {
+        throw takeFromExternrefTable0(ret[0]);
+    }
+}
+
+/**
+ * Register the IndexedDB-backed VFS and open the database.
+ *
+ * Migrations run inside `init_standalone`, exactly as they do for the CLI.
+ * Safe to call more than once; later calls are no-ops.
+ * @returns {Promise<void>}
+ */
+export function boot() {
+    const ret = wasm.boot();
+    return ret;
+}
+
+/**
+ * Run one command as `label` (the calling tab's identity, which stands in for
+ * the desktop's window label on every write it makes).
+ *
+ * The payload shapes match the `Cmd*Req` types in `yaak-rpc-schema` — that
+ * crate itself pulls the git, gRPC and plugin crates for their response types
+ * and cannot come to wasm, so the handful needed here are declared locally.
+ * @param {string} cmd
+ * @param {any} payload
+ * @param {string} label
+ * @returns {any}
+ */
+export function rpc(cmd, payload, label) {
+    const ptr0 = passStringToWasm0(cmd, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len0 = WASM_VECTOR_LEN;
+    const ptr1 = passStringToWasm0(label, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    const ret = wasm.rpc(ptr0, len0, payload, ptr1, len1);
+    if (ret[2]) {
+        throw takeFromExternrefTable0(ret[1]);
+    }
+    return takeFromExternrefTable0(ret[0]);
+}
+export function __wbg_Error_bce6d499ff0a4aff(arg0, arg1) {
+    const ret = Error(getStringFromWasm0(arg0, arg1));
+    return ret;
+}
+export function __wbg_String_8564e559799eccda(arg0, arg1) {
+    const ret = String(arg1);
+    const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg_Window_70131fc0c91e4b3c(arg0) {
+    const ret = arg0.Window;
+    return ret;
+}
+export function __wbg_WorkerGlobalScope_601c48015b8cc78e(arg0) {
+    const ret = arg0.WorkerGlobalScope;
+    return ret;
+}
+export function __wbg___wbindgen_bigint_get_as_i64_410e28c7b761ad83(arg0, arg1) {
+    const v = arg1;
+    const ret = typeof(v) === 'bigint' ? v : undefined;
+    getDataViewMemory0().setBigInt64(arg0 + 8 * 1, isLikeNone(ret) ? BigInt(0) : ret, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, !isLikeNone(ret), true);
+}
+export function __wbg___wbindgen_boolean_get_2304fb8c853028c8(arg0) {
+    const v = arg0;
+    const ret = typeof(v) === 'boolean' ? v : undefined;
+    return isLikeNone(ret) ? 0xFFFFFF : ret ? 1 : 0;
+}
+export function __wbg___wbindgen_debug_string_edece8177ad01481(arg0, arg1) {
+    const ret = debugString(arg1);
+    const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg___wbindgen_in_07056af4f902c445(arg0, arg1) {
+    const ret = arg0 in arg1;
+    return ret;
+}
+export function __wbg___wbindgen_is_bigint_aeae3893f30ed54e(arg0) {
+    const ret = typeof(arg0) === 'bigint';
+    return ret;
+}
+export function __wbg___wbindgen_is_function_5cd60d5cf78b4eef(arg0) {
+    const ret = typeof(arg0) === 'function';
+    return ret;
+}
+export function __wbg___wbindgen_is_null_2042690d351e14f0(arg0) {
+    const ret = arg0 === null;
+    return ret;
+}
+export function __wbg___wbindgen_is_object_b4593df85baada48(arg0) {
+    const val = arg0;
+    const ret = typeof(val) === 'object' && val !== null;
+    return ret;
+}
+export function __wbg___wbindgen_is_string_dde0fd9020db4434(arg0) {
+    const ret = typeof(arg0) === 'string';
+    return ret;
+}
+export function __wbg___wbindgen_is_undefined_35bb9f4c7fd651d5(arg0) {
+    const ret = arg0 === undefined;
+    return ret;
+}
+export function __wbg___wbindgen_jsval_eq_c0ed08b3e0f393b9(arg0, arg1) {
+    const ret = arg0 === arg1;
+    return ret;
+}
+export function __wbg___wbindgen_jsval_loose_eq_0ad77b7717db155c(arg0, arg1) {
+    const ret = arg0 == arg1;
+    return ret;
+}
+export function __wbg___wbindgen_number_get_f73a1244370fcc2c(arg0, arg1) {
+    const obj = arg1;
+    const ret = typeof(obj) === 'number' ? obj : undefined;
+    getDataViewMemory0().setFloat64(arg0 + 8 * 1, isLikeNone(ret) ? 0 : ret, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, !isLikeNone(ret), true);
+}
+export function __wbg___wbindgen_string_get_d109740c0d18f4d7(arg0, arg1) {
+    const obj = arg1;
+    const ret = typeof(obj) === 'string' ? obj : undefined;
+    var ptr1 = isLikeNone(ret) ? 0 : passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    var len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg___wbindgen_throw_9c31b086c2b26051(arg0, arg1) {
+    throw new Error(getStringFromWasm0(arg0, arg1));
+}
+export function __wbg__wbg_cb_unref_3fa391f3fcdb55f8(arg0) {
+    arg0._wbg_cb_unref();
+}
+export function __wbg_abort_70a701fced9ad53a() { return handleError(function (arg0) {
+    arg0.abort();
+}, arguments); }
+export function __wbg_bound_8d5dfa042d13a74b() { return handleError(function (arg0, arg1, arg2, arg3) {
+    const ret = IDBKeyRange.bound(arg0, arg1, arg2 !== 0, arg3 !== 0);
+    return ret;
+}, arguments); }
+export function __wbg_call_13665d9f14390edc() { return handleError(function (arg0, arg1) {
+    const ret = arg0.call(arg1);
+    return ret;
+}, arguments); }
+export function __wbg_call_dfde26266607c996() { return handleError(function (arg0, arg1, arg2) {
+    const ret = arg0.call(arg1, arg2);
+    return ret;
+}, arguments); }
+export function __wbg_clear_bb1b3ff877b62598() { return handleError(function (arg0) {
+    const ret = arg0.clear();
+    return ret;
+}, arguments); }
+export function __wbg_commit_e9c1332714c53826() { return handleError(function (arg0) {
+    arg0.commit();
+}, arguments); }
+export function __wbg_createObjectStore_7aa4cf3fcb65c75a() { return handleError(function (arg0, arg1, arg2, arg3) {
+    const ret = arg0.createObjectStore(getStringFromWasm0(arg1, arg2), arg3);
+    return ret;
+}, arguments); }
+export function __wbg_crypto_48300657fced39f9(arg0) {
+    const ret = arg0.crypto;
+    return ret;
+}
+export function __wbg_delete_bc03f88e7f14db56() { return handleError(function (arg0, arg1) {
+    const ret = arg0.delete(arg1);
+    return ret;
+}, arguments); }
+export function __wbg_done_54b8da57023b7ed2(arg0) {
+    const ret = arg0.done;
+    return ret;
+}
+export function __wbg_entries_564a7e8b1e54ede5(arg0) {
+    const ret = Object.entries(arg0);
+    return ret;
+}
+export function __wbg_error_a6fa202b58aa1cd3(arg0, arg1) {
+    let deferred0_0;
+    let deferred0_1;
+    try {
+        deferred0_0 = arg0;
+        deferred0_1 = arg1;
+        console.error(getStringFromWasm0(arg0, arg1));
+    } finally {
+        wasm.__wbindgen_free(deferred0_0, deferred0_1, 1);
+    }
+}
+export function __wbg_error_ef9cbaece146d1d5() { return handleError(function (arg0) {
+    const ret = arg0.error;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}, arguments); }
+export function __wbg_getAll_a0a54eef6ac20915() { return handleError(function (arg0, arg1) {
+    const ret = arg0.getAll(arg1);
+    return ret;
+}, arguments); }
+export function __wbg_getAll_bc4f4ec6a1504163() { return handleError(function (arg0) {
+    const ret = arg0.getAll();
+    return ret;
+}, arguments); }
+export function __wbg_getDate_a52123c8affc9072(arg0) {
+    const ret = arg0.getDate();
+    return ret;
+}
+export function __wbg_getDay_50a9ee1e4d17dc24(arg0) {
+    const ret = arg0.getDay();
+    return ret;
+}
+export function __wbg_getFullYear_d5d1f7de344fdc5b(arg0) {
+    const ret = arg0.getFullYear();
+    return ret;
+}
+export function __wbg_getHours_c974d920209733e8(arg0) {
+    const ret = arg0.getHours();
+    return ret;
+}
+export function __wbg_getMinutes_e2e8ae846b37b328(arg0) {
+    const ret = arg0.getMinutes();
+    return ret;
+}
+export function __wbg_getMonth_de70091920053153(arg0) {
+    const ret = arg0.getMonth();
+    return ret;
+}
+export function __wbg_getRandomValues_15134f5c0ae6b0d0() { return handleError(function (arg0, arg1) {
+    globalThis.crypto.getRandomValues(getArrayU8FromWasm0(arg0, arg1));
+}, arguments); }
+export function __wbg_getRandomValues_263d0aa5464054ee() { return handleError(function (arg0, arg1) {
+    arg0.getRandomValues(arg1);
+}, arguments); }
+export function __wbg_getSeconds_2782a558f414ec05(arg0) {
+    const ret = arg0.getSeconds();
+    return ret;
+}
+export function __wbg_getTime_09f1dd40a44edb30(arg0) {
+    const ret = arg0.getTime();
+    return ret;
+}
+export function __wbg_getTimezoneOffset_96cfb6ddebc9e5ca(arg0) {
+    const ret = arg0.getTimezoneOffset();
+    return ret;
+}
+export function __wbg_get_3e9a707ab7d352eb() { return handleError(function (arg0, arg1) {
+    const ret = Reflect.get(arg0, arg1);
+    return ret;
+}, arguments); }
+export function __wbg_get_98fdf51d029a75eb(arg0, arg1) {
+    const ret = arg0[arg1 >>> 0];
+    return ret;
+}
+export function __wbg_get_dcf82ab8aad1a593() { return handleError(function (arg0, arg1) {
+    const ret = Reflect.get(arg0, arg1);
+    return ret;
+}, arguments); }
+export function __wbg_get_unchecked_1dfe6d05ad91d9b7(arg0, arg1) {
+    const ret = arg0[arg1 >>> 0];
+    return ret;
+}
+export function __wbg_get_with_ref_key_6412cf3094599694(arg0, arg1) {
+    const ret = arg0[arg1];
+    return ret;
+}
+export function __wbg_global_e30ac0b7684506d0(arg0) {
+    const ret = arg0.global;
+    return ret;
+}
+export function __wbg_indexedDB_2e82cb845ce6b3ad() { return handleError(function (arg0) {
+    const ret = arg0.indexedDB;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}, arguments); }
+export function __wbg_indexedDB_a2139150e2ea2a08() { return handleError(function (arg0) {
+    const ret = arg0.indexedDB;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}, arguments); }
+export function __wbg_indexedDB_cbfeacc981615a77() { return handleError(function (arg0) {
+    const ret = arg0.indexedDB;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}, arguments); }
+export function __wbg_instanceof_ArrayBuffer_53db37b06f6b9afe(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof ArrayBuffer;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_DomException_bc16ce893e8c7439(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof DOMException;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_Error_b3f7e146d654031a(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof Error;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_IdbDatabase_102b0fe5255eee9c(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof IDBDatabase;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_IdbRequest_eef501cff5d0b7c1(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof IDBRequest;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_Map_16f217b9a2a08d8c(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof Map;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_instanceof_Uint8Array_abd07d4bd221d50b(arg0) {
+    let result;
+    try {
+        result = arg0 instanceof Uint8Array;
+    } catch (_) {
+        result = false;
+    }
+    const ret = result;
+    return ret;
+}
+export function __wbg_isArray_94898ed3aad6947b(arg0) {
+    const ret = Array.isArray(arg0);
+    return ret;
+}
+export function __wbg_isSafeInteger_01e964d144ad3a55(arg0) {
+    const ret = Number.isSafeInteger(arg0);
+    return ret;
+}
+export function __wbg_iterator_1441b47f341dc34f() {
+    const ret = Symbol.iterator;
+    return ret;
+}
+export function __wbg_length_2591a0f4f659a55c(arg0) {
+    const ret = arg0.length;
+    return ret;
+}
+export function __wbg_length_56fcd3e2b7e0299d(arg0) {
+    const ret = arg0.length;
+    return ret;
+}
+export function __wbg_lowerBound_a64226f683db77bb() { return handleError(function (arg0, arg1) {
+    const ret = IDBKeyRange.lowerBound(arg0, arg1 !== 0);
+    return ret;
+}, arguments); }
+export function __wbg_message_324ac511aeaf710e(arg0) {
+    const ret = arg0.message;
+    return ret;
+}
+export function __wbg_message_e88a8d3ba2b91c2a(arg0, arg1) {
+    const ret = arg1.message;
+    const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg_msCrypto_8c6d45a75ef1d3da(arg0) {
+    const ret = arg0.msCrypto;
+    return ret;
+}
+export function __wbg_name_fe88cfc178ec40b8(arg0, arg1) {
+    const ret = arg1.name;
+    const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg_new_02d162bc6cf02f60() {
+    const ret = new Object();
+    return ret;
+}
+export function __wbg_new_070df68d66325372() {
+    const ret = new Map();
+    return ret;
+}
+export function __wbg_new_0_2722fcdb71a888a6() {
+    const ret = new Date();
+    return ret;
+}
+export function __wbg_new_1f236d63ba0c4784(arg0, arg1) {
+    const ret = new Error(getStringFromWasm0(arg0, arg1));
+    return ret;
+}
+export function __wbg_new_227d7c05414eb861() {
+    const ret = new Error();
+    return ret;
+}
+export function __wbg_new_310879b66b6e95e1() {
+    const ret = new Array();
+    return ret;
+}
+export function __wbg_new_7ddec6de44ff8f5d(arg0) {
+    const ret = new Uint8Array(arg0);
+    return ret;
+}
+export function __wbg_new_859b9002e2668e82(arg0) {
+    const ret = new Date(arg0);
+    return ret;
+}
+export function __wbg_new_from_slice_269e35316ed2d061(arg0, arg1) {
+    const ret = new Uint8Array(getArrayU8FromWasm0(arg0, arg1));
+    return ret;
+}
+export function __wbg_new_typed_c072c4ce9a2a0cdf(arg0, arg1) {
+    try {
+        var state0 = {a: arg0, b: arg1};
+        var cb0 = (arg0, arg1) => {
+            const a = state0.a;
+            state0.a = 0;
+            try {
+                return wasm_bindgen__convert__closures_____invoke__h2c72ca09e851b7f3(a, state0.b, arg0, arg1);
+            } finally {
+                state0.a = a;
+            }
+        };
+        const ret = new Promise(cb0);
+        return ret;
+    } finally {
+        state0.a = 0;
+    }
+}
+export function __wbg_new_with_length_99887c91eae4abab(arg0) {
+    const ret = new Uint8Array(arg0 >>> 0);
+    return ret;
+}
+export function __wbg_new_with_year_month_day_0ccdc1cc3a42b726(arg0, arg1, arg2) {
+    const ret = new Date(arg0 >>> 0, arg1, arg2);
+    return ret;
+}
+export function __wbg_next_2a4e19f4f5083b0f(arg0) {
+    const ret = arg0.next;
+    return ret;
+}
+export function __wbg_next_6429a146bf756f93() { return handleError(function (arg0) {
+    const ret = arg0.next();
+    return ret;
+}, arguments); }
+export function __wbg_node_95beb7570492fd97(arg0) {
+    const ret = arg0.node;
+    return ret;
+}
+export function __wbg_objectStore_b28adb984a77902e() { return handleError(function (arg0, arg1, arg2) {
+    const ret = arg0.objectStore(getStringFromWasm0(arg1, arg2));
+    return ret;
+}, arguments); }
+export function __wbg_open_40ab11cdd8f5ac5a() { return handleError(function (arg0, arg1, arg2, arg3) {
+    const ret = arg0.open(getStringFromWasm0(arg1, arg2), arg3 >>> 0);
+    return ret;
+}, arguments); }
+export function __wbg_process_b2fea42461d03994(arg0) {
+    const ret = arg0.process;
+    return ret;
+}
+export function __wbg_prototypesetcall_5f9bdc8d75e07276(arg0, arg1, arg2) {
+    Uint8Array.prototype.set.call(getArrayU8FromWasm0(arg0, arg1), arg2);
+}
+export function __wbg_push_b77c476b01548d0a(arg0, arg1) {
+    const ret = arg0.push(arg1);
+    return ret;
+}
+export function __wbg_put_848906967513a84d() { return handleError(function (arg0, arg1) {
+    const ret = arg0.put(arg1);
+    return ret;
+}, arguments); }
+export function __wbg_queueMicrotask_78d584b53af520f5(arg0) {
+    const ret = arg0.queueMicrotask;
+    return ret;
+}
+export function __wbg_queueMicrotask_b39ea83c7f01971a(arg0) {
+    queueMicrotask(arg0);
+}
+export function __wbg_randomFillSync_ca9f178fb14c88cb() { return handleError(function (arg0, arg1) {
+    arg0.randomFillSync(arg1);
+}, arguments); }
+export function __wbg_random_a8dfe52b70cb65a5() {
+    const ret = Math.random();
+    return ret;
+}
+export function __wbg_readyState_b7c530197b76b93b(arg0) {
+    const ret = arg0.readyState;
+    return (__wbindgen_enum_IdbRequestReadyState.indexOf(ret) + 1 || 3) - 1;
+}
+export function __wbg_require_7a9419e39d796c95() { return handleError(function () {
+    const ret = module.require;
+    return ret;
+}, arguments); }
+export function __wbg_resolve_d17db9352f5a220e(arg0) {
+    const ret = Promise.resolve(arg0);
+    return ret;
+}
+export function __wbg_result_c4cb33cd39c97cac() { return handleError(function (arg0) {
+    const ret = arg0.result;
+    return ret;
+}, arguments); }
+export function __wbg_set_24d0fa9e104112f9(arg0, arg1, arg2) {
+    arg0.set(getArrayU8FromWasm0(arg1, arg2));
+}
+export function __wbg_set_6be42768c690e380(arg0, arg1, arg2) {
+    arg0[arg1] = arg2;
+}
+export function __wbg_set_78ea6a19f4818587(arg0, arg1, arg2) {
+    arg0[arg1 >>> 0] = arg2;
+}
+export function __wbg_set_a0e911be3da02782() { return handleError(function (arg0, arg1, arg2) {
+    const ret = Reflect.set(arg0, arg1, arg2);
+    return ret;
+}, arguments); }
+export function __wbg_set_facb7a5914e0fa39(arg0, arg1, arg2) {
+    const ret = arg0.set(arg1, arg2);
+    return ret;
+}
+export function __wbg_set_key_path_8f8e19a098d0851c(arg0, arg1) {
+    arg0.keyPath = arg1;
+}
+export function __wbg_set_onabort_ed56d2172d920901(arg0, arg1) {
+    arg0.onabort = arg1;
+}
+export function __wbg_set_oncomplete_3f428ec13b20d7cc(arg0, arg1) {
+    arg0.oncomplete = arg1;
+}
+export function __wbg_set_onerror_38740b892815eedc(arg0, arg1) {
+    arg0.onerror = arg1;
+}
+export function __wbg_set_onerror_457b093a5063c7ec(arg0, arg1) {
+    arg0.onerror = arg1;
+}
+export function __wbg_set_onsuccess_b556141053d02ea7(arg0, arg1) {
+    arg0.onsuccess = arg1;
+}
+export function __wbg_set_onupgradeneeded_f885fa17614acd2b(arg0, arg1) {
+    arg0.onupgradeneeded = arg1;
+}
+export function __wbg_stack_3b0d974bbf31e44f(arg0, arg1) {
+    const ret = arg1.stack;
+    const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+    const len1 = WASM_VECTOR_LEN;
+    getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+    getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+}
+export function __wbg_static_accessor_GLOBAL_THIS_02344c9b09eb08a9() {
+    const ret = typeof globalThis === 'undefined' ? null : globalThis;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}
+export function __wbg_static_accessor_GLOBAL_ac6d4ac874d5cd54() {
+    const ret = typeof global === 'undefined' ? null : global;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}
+export function __wbg_static_accessor_SELF_9b2406c23aeb2023() {
+    const ret = typeof self === 'undefined' ? null : self;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}
+export function __wbg_static_accessor_WINDOW_b34d2126934e16ba() {
+    const ret = typeof window === 'undefined' ? null : window;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}
+export function __wbg_subarray_7c6a0da8f3b4a1ba(arg0, arg1, arg2) {
+    const ret = arg0.subarray(arg1 >>> 0, arg2 >>> 0);
+    return ret;
+}
+export function __wbg_target_84e05e84ffc12989(arg0) {
+    const ret = arg0.target;
+    return isLikeNone(ret) ? 0 : addToExternrefTable0(ret);
+}
+export function __wbg_then_837494e384b37459(arg0, arg1) {
+    const ret = arg0.then(arg1);
+    return ret;
+}
+export function __wbg_toString_1dda136fd8f30a5f(arg0) {
+    const ret = arg0.toString();
+    return ret;
+}
+export function __wbg_transaction_213e4f585d3d1b40(arg0) {
+    const ret = arg0.transaction;
+    return ret;
+}
+export function __wbg_transaction_b7261fed68fa4264() { return handleError(function (arg0, arg1, arg2, arg3) {
+    const ret = arg0.transaction(getStringFromWasm0(arg1, arg2), __wbindgen_enum_IdbTransactionMode[arg3]);
+    return ret;
+}, arguments); }
+export function __wbg_upperBound_f7daa7529e579cfc() { return handleError(function (arg0, arg1) {
+    const ret = IDBKeyRange.upperBound(arg0, arg1 !== 0);
+    return ret;
+}, arguments); }
+export function __wbg_value_9cc0518af87a489c(arg0) {
+    const ret = arg0.value;
+    return ret;
+}
+export function __wbg_versions_215a3ab1c9d5745a(arg0) {
+    const ret = arg0.versions;
+    return ret;
+}
+export function __wbindgen_cast_0000000000000001(arg0, arg1) {
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [Externref], shim_idx: 1104, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
+    const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__hf84d53817e0238b4);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000002(arg0, arg1) {
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("Event")], shim_idx: 202, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
+    const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__h7e06bb925b918fbb);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000003(arg0, arg1) {
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [NamedExternref("IDBVersionChangeEvent")], shim_idx: 180, ret: Result(Unit), inner_ret: Some(Result(Unit)) }, mutable: true }) -> Externref`.
+    const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__ha579407f9663b071);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000004(arg0, arg1) {
+    // Cast intrinsic for `Closure(Closure { owned: true, function: Function { arguments: [], shim_idx: 200, ret: Unit, inner_ret: Some(Unit) }, mutable: true }) -> Externref`.
+    const ret = makeMutClosure(arg0, arg1, wasm_bindgen__convert__closures_____invoke__h87640adb2bbfa2fc);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000005(arg0) {
+    // Cast intrinsic for `F64 -> Externref`.
+    const ret = arg0;
+    return ret;
+}
+export function __wbindgen_cast_0000000000000006(arg0) {
+    // Cast intrinsic for `I64 -> Externref`.
+    const ret = arg0;
+    return ret;
+}
+export function __wbindgen_cast_0000000000000007(arg0, arg1) {
+    // Cast intrinsic for `Ref(Slice(U8)) -> NamedExternref("Uint8Array")`.
+    const ret = getArrayU8FromWasm0(arg0, arg1);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000008(arg0, arg1) {
+    // Cast intrinsic for `Ref(String) -> Externref`.
+    const ret = getStringFromWasm0(arg0, arg1);
+    return ret;
+}
+export function __wbindgen_cast_0000000000000009(arg0) {
+    // Cast intrinsic for `U64 -> Externref`.
+    const ret = BigInt.asUintN(64, arg0);
+    return ret;
+}
+export function __wbindgen_init_externref_table() {
+    const table = wasm.__wbindgen_externrefs;
+    const offset = table.grow(4);
+    table.set(0, undefined);
+    table.set(offset + 0, undefined);
+    table.set(offset + 1, null);
+    table.set(offset + 2, true);
+    table.set(offset + 3, false);
+}
+function wasm_bindgen__convert__closures_____invoke__h87640adb2bbfa2fc(arg0, arg1) {
+    wasm.wasm_bindgen__convert__closures_____invoke__h87640adb2bbfa2fc(arg0, arg1);
+}
+
+function wasm_bindgen__convert__closures_____invoke__h7e06bb925b918fbb(arg0, arg1, arg2) {
+    wasm.wasm_bindgen__convert__closures_____invoke__h7e06bb925b918fbb(arg0, arg1, arg2);
+}
+
+function wasm_bindgen__convert__closures_____invoke__hf84d53817e0238b4(arg0, arg1, arg2) {
+    const ret = wasm.wasm_bindgen__convert__closures_____invoke__hf84d53817e0238b4(arg0, arg1, arg2);
+    if (ret[1]) {
+        throw takeFromExternrefTable0(ret[0]);
+    }
+}
+
+function wasm_bindgen__convert__closures_____invoke__ha579407f9663b071(arg0, arg1, arg2) {
+    const ret = wasm.wasm_bindgen__convert__closures_____invoke__ha579407f9663b071(arg0, arg1, arg2);
+    if (ret[1]) {
+        throw takeFromExternrefTable0(ret[0]);
+    }
+}
+
+function wasm_bindgen__convert__closures_____invoke__h2c72ca09e851b7f3(arg0, arg1, arg2, arg3) {
+    wasm.wasm_bindgen__convert__closures_____invoke__h2c72ca09e851b7f3(arg0, arg1, arg2, arg3);
+}
+
+
+const __wbindgen_enum_IdbRequestReadyState = ["pending", "done"];
+
+
+const __wbindgen_enum_IdbTransactionMode = ["readonly", "readwrite", "versionchange", "readwriteflush", "cleanup"];
+
+function addToExternrefTable0(obj) {
+    const idx = wasm.__externref_table_alloc();
+    wasm.__wbindgen_externrefs.set(idx, obj);
+    return idx;
+}
+
+const CLOSURE_DTORS = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(state => wasm.__wbindgen_destroy_closure(state.a, state.b));
+
+function debugString(val) {
+    // primitive types
+    const type = typeof val;
+    if (type == 'number' || type == 'boolean' || val == null) {
+        return  `${val}`;
+    }
+    if (type == 'string') {
+        return `"${val}"`;
+    }
+    if (type == 'symbol') {
+        const description = val.description;
+        if (description == null) {
+            return 'Symbol';
+        } else {
+            return `Symbol(${description})`;
+        }
+    }
+    if (type == 'function') {
+        const name = val.name;
+        if (typeof name == 'string' && name.length > 0) {
+            return `Function(${name})`;
+        } else {
+            return 'Function';
+        }
+    }
+    // objects
+    if (Array.isArray(val)) {
+        const length = val.length;
+        let debug = '[';
+        if (length > 0) {
+            debug += debugString(val[0]);
+        }
+        for(let i = 1; i < length; i++) {
+            debug += ', ' + debugString(val[i]);
+        }
+        debug += ']';
+        return debug;
+    }
+    // Test for built-in
+    const builtInMatches = /\[object ([^\]]+)\]/.exec(toString.call(val));
+    let className;
+    if (builtInMatches && builtInMatches.length > 1) {
+        className = builtInMatches[1];
+    } else {
+        // Failed to match the standard '[object ClassName]'
+        return toString.call(val);
+    }
+    if (className == 'Object') {
+        // we're a user defined class or Object
+        // JSON.stringify avoids problems with cycles, and is generally much
+        // easier than looping through ownProperties of `val`.
+        try {
+            return 'Object(' + JSON.stringify(val) + ')';
+        } catch (_) {
+            return 'Object';
+        }
+    }
+    // errors
+    if (val instanceof Error) {
+        return `${val.name}: ${val.message}\n${val.stack}`;
+    }
+    // TODO we could test for more things here, like `Set`s and `Map`s.
+    return className;
+}
+
+function getArrayU8FromWasm0(ptr, len) {
+    ptr = ptr >>> 0;
+    return getUint8ArrayMemory0().subarray(ptr / 1, ptr / 1 + len);
+}
+
+let cachedDataViewMemory0 = null;
+function getDataViewMemory0() {
+    if (cachedDataViewMemory0 === null || cachedDataViewMemory0.buffer.detached === true || (cachedDataViewMemory0.buffer.detached === undefined && cachedDataViewMemory0.buffer !== wasm.memory.buffer)) {
+        cachedDataViewMemory0 = new DataView(wasm.memory.buffer);
+    }
+    return cachedDataViewMemory0;
+}
+
+function getStringFromWasm0(ptr, len) {
+    return decodeText(ptr >>> 0, len);
+}
+
+let cachedUint8ArrayMemory0 = null;
+function getUint8ArrayMemory0() {
+    if (cachedUint8ArrayMemory0 === null || cachedUint8ArrayMemory0.byteLength === 0) {
+        cachedUint8ArrayMemory0 = new Uint8Array(wasm.memory.buffer);
+    }
+    return cachedUint8ArrayMemory0;
+}
+
+function handleError(f, args) {
+    try {
+        return f.apply(this, args);
+    } catch (e) {
+        const idx = addToExternrefTable0(e);
+        wasm.__wbindgen_exn_store(idx);
+    }
+}
+
+function isLikeNone(x) {
+    return x === undefined || x === null;
+}
+
+function makeMutClosure(arg0, arg1, f) {
+    const state = { a: arg0, b: arg1, cnt: 1 };
+    const real = (...args) => {
+
+        // First up with a closure we increment the internal reference
+        // count. This ensures that the Rust closure environment won't
+        // be deallocated while we're invoking it.
+        state.cnt++;
+        const a = state.a;
+        state.a = 0;
+        try {
+            return f(a, state.b, ...args);
+        } finally {
+            state.a = a;
+            real._wbg_cb_unref();
+        }
+    };
+    real._wbg_cb_unref = () => {
+        if (--state.cnt === 0) {
+            wasm.__wbindgen_destroy_closure(state.a, state.b);
+            state.a = 0;
+            CLOSURE_DTORS.unregister(state);
+        }
+    };
+    CLOSURE_DTORS.register(real, state, state);
+    return real;
+}
+
+function passArray8ToWasm0(arg, malloc) {
+    const ptr = malloc(arg.length * 1, 1) >>> 0;
+    getUint8ArrayMemory0().set(arg, ptr / 1);
+    WASM_VECTOR_LEN = arg.length;
+    return ptr;
+}
+
+function passStringToWasm0(arg, malloc, realloc) {
+    if (realloc === undefined) {
+        const buf = cachedTextEncoder.encode(arg);
+        const ptr = malloc(buf.length, 1) >>> 0;
+        getUint8ArrayMemory0().subarray(ptr, ptr + buf.length).set(buf);
+        WASM_VECTOR_LEN = buf.length;
+        return ptr;
+    }
+
+    let len = arg.length;
+    let ptr = malloc(len, 1) >>> 0;
+
+    const mem = getUint8ArrayMemory0();
+
+    let offset = 0;
+
+    for (; offset < len; offset++) {
+        const code = arg.charCodeAt(offset);
+        if (code > 0x7F) break;
+        mem[ptr + offset] = code;
+    }
+    if (offset !== len) {
+        if (offset !== 0) {
+            arg = arg.slice(offset);
+        }
+        ptr = realloc(ptr, len, len = offset + arg.length * 3, 1) >>> 0;
+        const view = getUint8ArrayMemory0().subarray(ptr + offset, ptr + len);
+        const ret = cachedTextEncoder.encodeInto(arg, view);
+
+        offset += ret.written;
+        ptr = realloc(ptr, len, offset, 1) >>> 0;
+    }
+
+    WASM_VECTOR_LEN = offset;
+    return ptr;
+}
+
+function takeFromExternrefTable0(idx) {
+    const value = wasm.__wbindgen_externrefs.get(idx);
+    wasm.__externref_table_dealloc(idx);
+    return value;
+}
+
+let cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+cachedTextDecoder.decode();
+const MAX_SAFARI_DECODE_BYTES = 2146435072;
+let numBytesDecoded = 0;
+function decodeText(ptr, len) {
+    numBytesDecoded += len;
+    if (numBytesDecoded >= MAX_SAFARI_DECODE_BYTES) {
+        cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+        cachedTextDecoder.decode();
+        numBytesDecoded = len;
+    }
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
+const cachedTextEncoder = new TextEncoder();
+
+if (!('encodeInto' in cachedTextEncoder)) {
+    cachedTextEncoder.encodeInto = function (arg, view) {
+        const buf = cachedTextEncoder.encode(arg);
+        view.set(buf);
+        return {
+            read: arg.length,
+            written: buf.length
+        };
+    };
+}
+
+let WASM_VECTOR_LEN = 0;
+
+
+let wasm;
+export function __wbg_set_wasm(val) {
+    wasm = val;
+}
@@ -0,0 +1,32 @@
+/* tslint:disable */
+/* eslint-disable */
+export const memory: WebAssembly.Memory;
+export const blob_delete: (a: number, b: number) => [number, number];
+export const blob_get: (a: number, b: number) => [number, number, number, number];
+export const blob_put: (a: number, b: number, c: number, d: number) => [number, number];
+export const boot: () => any;
+export const rpc: (a: number, b: number, c: any, d: number, e: number) => [number, number, number];
+export const rust_sqlite_wasm_abort: () => void;
+export const rust_sqlite_wasm_assert_fail: (a: number, b: number, c: number, d: number) => void;
+export const rust_sqlite_wasm_calloc: (a: number, b: number) => number;
+export const rust_sqlite_wasm_free: (a: number) => void;
+export const rust_sqlite_wasm_getentropy: (a: number, b: number) => number;
+export const rust_sqlite_wasm_localtime: (a: number) => number;
+export const rust_sqlite_wasm_malloc: (a: number) => number;
+export const rust_sqlite_wasm_realloc: (a: number, b: number) => number;
+export const sqlite3_os_end: () => number;
+export const sqlite3_os_init: () => number;
+export const wasm_bindgen__convert__closures_____invoke__hf84d53817e0238b4: (a: number, b: number, c: any) => [number, number];
+export const wasm_bindgen__convert__closures_____invoke__ha579407f9663b071: (a: number, b: number, c: any) => [number, number];
+export const wasm_bindgen__convert__closures_____invoke__h2c72ca09e851b7f3: (a: number, b: number, c: any, d: any) => void;
+export const wasm_bindgen__convert__closures_____invoke__h7e06bb925b918fbb: (a: number, b: number, c: any) => void;
+export const wasm_bindgen__convert__closures_____invoke__h87640adb2bbfa2fc: (a: number, b: number) => void;
+export const __wbindgen_malloc: (a: number, b: number) => number;
+export const __wbindgen_realloc: (a: number, b: number, c: number, d: number) => number;
+export const __wbindgen_exn_store: (a: number) => void;
+export const __externref_table_alloc: () => number;
+export const __wbindgen_externrefs: WebAssembly.Table;
+export const __wbindgen_free: (a: number, b: number, c: number) => void;
+export const __wbindgen_destroy_closure: (a: number, b: number) => void;
+export const __externref_table_dealloc: (a: number) => void;
+export const __wbindgen_start: () => void;
@@ -0,0 +1,356 @@
+//! The desktop's model layer, running in a browser.
+//!
+//! Nothing here is model logic. This crate registers a persistent VFS, opens
+//! the database through the same `init_standalone` the CLI uses, and answers
+//! the `models_*` commands by calling the same `ClientDb` queries the desktop
+//! does. A browser tab therefore stores exactly what a desktop install stores,
+//! migrations and all — the only thing that differs is where the SQLite pages
+//! live (IndexedDB) and who is calling in (a worker instead of Tauri).
+//!
+//! It is meant to be loaded once, in one place — a SharedWorker — because two
+//! SQLite instances over the same IndexedDB pages would corrupt them. The
+//! JavaScript side owns that; this crate assumes it is the only writer.
+//!
+//! The command surface is deliberately narrow: what the frontend needs to keep
+//! its model store coherent, and blob storage. Sending, plugins, git, sync and
+//! everything else with a socket or a filesystem behind it lives elsewhere.
+
+// Nothing in here means anything off wasm32, and building it there would drag
+// SQLite's wasm C shim into a native compile. So on any other target the crate
+// is empty — a workspace-wide `cargo test` passes through it.
+#![cfg(target_arch = "wasm32")]
+
+use std::cell::RefCell;
+use std::sync::mpsc;
+
+use serde::{Deserialize, Serialize};
+use wasm_bindgen::prelude::*;
+use yaak_models::blob_manager::{BlobManager, BodyChunk};
+use yaak_models::models::AnyModel;
+use yaak_models::models_ops;
+use yaak_models::query_manager::QueryManager;
+use yaak_models::util::{ModelPayload, UpdateSource};
+
+/// Names inside the VFS, not paths on any disk. Two files because the desktop
+/// keeps two: models in one, blobs in the other.
+const DB_NAME: &str = "yaak.db";
+const BLOB_DB_NAME: &str = "yaak-blobs.db";
+const VFS_NAME: &str = "yaak-idb";
+
+struct Host {
+    queries: QueryManager,
+    blobs: BlobManager,
+    events: mpsc::Receiver<ModelPayload>,
+}
+
+thread_local! {
+    static HOST: RefCell<Option<Host>> = const { RefCell::new(None) };
+}
+
+/* -------------------------------------------------------------------------- */
+/* Errors                                                                      */
+/* -------------------------------------------------------------------------- */
+
+/// What a failed command hands back to JavaScript: a real `Error`, so it
+/// throws like one, with `message` set to the model layer's own text.
+fn js_error(e: impl std::fmt::Display) -> JsValue {
+    js_sys::Error::new(&e.to_string()).into()
+}
+
+type Result<T> = std::result::Result<T, JsValue>;
+
+/* -------------------------------------------------------------------------- */
+/* Boot                                                                        */
+/* -------------------------------------------------------------------------- */
+
+/// Register the IndexedDB-backed VFS and open the database.
+///
+/// Migrations run inside `init_standalone`, exactly as they do for the CLI.
+/// Safe to call more than once; later calls are no-ops.
+#[wasm_bindgen]
+pub async fn boot() -> Result<()> {
+    console_error_panic_hook::set_once();
+
+    if HOST.with(|h| h.borrow().is_some()) {
+        return Ok(());
+    }
+
+    // "Relaxed" means writes land in memory first and are flushed to
+    // IndexedDB shortly after, rather than on every commit. It is the right
+    // trade for a client app: a tab closing mid-flush loses at most the last
+    // few writes, and the alternative (OPFS sync access handles) needs a
+    // dedicated worker per file and is not available everywhere.
+    let cfg = sqlite_wasm_vfs::relaxed_idb::RelaxedIdbCfgBuilder::new()
+        .vfs_name(VFS_NAME)
+        .preload(sqlite_wasm_vfs::relaxed_idb::Preload::All)
+        .build();
+    sqlite_wasm_vfs::relaxed_idb::install::<sqlite_wasm_rs::WasmOsCallback>(&cfg, true)
+        .await
+        .map_err(js_error)?;
+
+    let (queries, blobs, events) =
+        yaak_models::init_standalone(DB_NAME, BLOB_DB_NAME).map_err(js_error)?;
+
+    HOST.with(|h| *h.borrow_mut() = Some(Host { queries, blobs, events }));
+    Ok(())
+}
+
+fn with_host<T>(f: impl FnOnce(&Host) -> Result<T>) -> Result<T> {
+    HOST.with(|h| {
+        let h = h.borrow();
+        let host = h.as_ref().ok_or_else(|| js_error("yaak-web: call boot() before rpc()"))?;
+        f(host)
+    })
+}
+
+/* -------------------------------------------------------------------------- */
+/* Commands                                                                    */
+/* -------------------------------------------------------------------------- */
+
+/// A command's outcome, plus every model write it caused.
+///
+/// The writes ride along with the result rather than being fetched separately
+/// so the caller can announce them atomically with completion — a tab that
+/// awaits `models_upsert` must see its echo before or with the response, never
+/// after, or the store races the reply.
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct RpcOutcome {
+    result: serde_json::Value,
+    events: Vec<ModelPayload>,
+}
+
+/// Run one command as `label` (the calling tab's identity, which stands in for
+/// the desktop's window label on every write it makes).
+///
+/// The payload shapes match the `Cmd*Req` types in `yaak-rpc-schema`, but are
+/// declared locally and dispatched by name, which is the one place this host
+/// does not share the desktop's guarantees: the desktop builds its router from
+/// the schema, so every command has a handler by construction. Here a renamed
+/// command would surface as a runtime "not a command this host answers".
+///
+/// The fix is `yaak-commands` (the `Host` trait), not more machinery here —
+/// its `models::*` handlers are already this file, typed. Three things have to
+/// give before a wasm host can register them:
+///
+/// 1. `Host: Send + Sync`, which a browser cannot satisfy: there is one thread
+///    and the connection pool is an `Rc`.
+/// 2. `models_delete` reaches for `spawn_blocking`; there is nothing to spawn
+///    onto here.
+/// 3. `yaak-commands` depends on `yaak` and `yaak-plugins`, which pull the HTTP
+///    stack and the Node sidecar and do not build for wasm32.
+///
+/// None of those are hard; they are just not this PR.
+#[wasm_bindgen]
+pub fn rpc(cmd: &str, payload: JsValue, label: &str) -> Result<JsValue> {
+    let source = UpdateSource::from_window_label(label);
+
+    let result = with_host(|host| dispatch(host, cmd, payload, &source))?;
+    let events = with_host(|host| Ok(host.events.try_iter().collect::<Vec<_>>()))?;
+
+    use serde::Serialize as _;
+    RpcOutcome { result, events }
+        .serialize(&serde_wasm_bindgen::Serializer::json_compatible())
+        .map_err(js_error)
+}
+
+fn from_js<T: for<'de> Deserialize<'de>>(payload: JsValue) -> Result<T> {
+    serde_wasm_bindgen::from_value(payload).map_err(js_error)
+}
+
+fn to_json<T: Serialize>(value: T) -> Result<serde_json::Value> {
+    serde_json::to_value(value).map_err(js_error)
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct WorkspaceModelsReq {
+    workspace_id: Option<String>,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct ModelReq {
+    model: AnyModel,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct DuplicateReq {
+    model_type: String,
+    model_id: String,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct WorkspaceIdReq {
+    workspace_id: String,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct RequestIdReq {
+    request_id: String,
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct UpsertIntrospectionReq {
+    workspace_id: String,
+    request_id: String,
+    content: Option<String>,
+}
+
+fn dispatch(
+    host: &Host,
+    cmd: &str,
+    payload: JsValue,
+    source: &UpdateSource,
+) -> Result<serde_json::Value> {
+    match cmd {
+        // The one big read. Same list, same order, and the same four lazy
+        // creates (settings, first workspace, cookie jar, base environment) as
+        // `models_workspace_models` on the desktop — this call is where an
+        // empty database becomes a usable one. Returned as a JSON *string*
+        // because that is what the desktop returns and what the store parses.
+        "models_workspace_models" => {
+            let req: WorkspaceModelsReq = from_js(payload)?;
+            let db = host.queries.connect();
+            let mut list: Vec<AnyModel> = Vec::new();
+
+            list.push(db.get_settings().into());
+            list.extend(db.list_workspaces().map_err(js_error)?.into_iter().map(Into::into));
+            list.extend(db.list_key_values().map_err(js_error)?.into_iter().map(Into::into));
+            // No plugin runtime to resolve these against; the rows are still
+            // the truth about what is installed.
+            list.extend(db.list_plugins().map_err(js_error)?.into_iter().map(Into::into));
+
+            if let Some(wid) = req.workspace_id.as_deref() {
+                let e = js_error;
+                list.extend(db.list_cookie_jars(wid).map_err(e)?.into_iter().map(Into::into));
+                list.extend(
+                    db.list_environments_ensure_base(wid).map_err(e)?.into_iter().map(Into::into),
+                );
+                list.extend(db.list_folders(wid).map_err(e)?.into_iter().map(Into::into));
+                list.extend(db.list_grpc_connections(wid).map_err(e)?.into_iter().map(Into::into));
+                list.extend(db.list_grpc_requests(wid).map_err(e)?.into_iter().map(Into::into));
+                list.extend(db.list_http_requests(wid).map_err(e)?.into_iter().map(Into::into));
+                list.extend(
+                    db.list_http_responses(wid, None).map_err(e)?.into_iter().map(Into::into),
+                );
+                list.extend(
+                    db.list_websocket_connections(wid).map_err(e)?.into_iter().map(Into::into),
+                );
+                list.extend(
+                    db.list_websocket_requests(wid).map_err(e)?.into_iter().map(Into::into),
+                );
+                list.extend(db.list_workspace_metas(wid).map_err(e)?.into_iter().map(Into::into));
+            }
+
+            to_json(serde_json::to_string(&list).map_err(js_error)?)
+        }
+
+        "models_upsert" => {
+            let req: ModelReq = from_js(payload)?;
+            let db = host.queries.connect();
+            let id =
+                models_ops::upsert_model(&db, &host.blobs, req.model, source).map_err(js_error)?;
+            to_json(id)
+        }
+
+        // Deletes and duplicates cascade, so they run in a transaction, as on
+        // the desktop.
+        "models_delete" => {
+            let req: ModelReq = from_js(payload)?;
+            let id = host
+                .queries
+                .with_tx(|tx| models_ops::delete_model(tx, &host.blobs, req.model, source))
+                .map_err(js_error)?;
+            to_json(id)
+        }
+
+        "models_duplicate" => {
+            let req: DuplicateReq = from_js(payload)?;
+            let id = host
+                .queries
+                .with_tx(|tx| {
+                    models_ops::duplicate_model(tx, &req.model_type, &req.model_id, source)
+                })
+                .map_err(js_error)?;
+            to_json(id)
+        }
+
+        "models_get_settings" => to_json(host.queries.connect().get_settings()),
+
+        "models_get_graphql_introspection" => {
+            let req: RequestIdReq = from_js(payload)?;
+            to_json(host.queries.connect().get_graphql_introspection(&req.request_id))
+        }
+
+        "models_upsert_graphql_introspection" => {
+            let req: UpsertIntrospectionReq = from_js(payload)?;
+            let saved = host
+                .queries
+                .connect()
+                .upsert_graphql_introspection(
+                    &req.workspace_id,
+                    &req.request_id,
+                    req.content,
+                    source,
+                )
+                .map_err(js_error)?;
+            to_json(saved)
+        }
+
+        // Nothing here can open a socket, so no connection ever produced any.
+        "models_grpc_events" | "models_websocket_events" => to_json(Vec::<()>::new()),
+
+        "cmd_get_workspace_meta" => {
+            let req: WorkspaceIdReq = from_js(payload)?;
+            let db = host.queries.connect();
+            let workspace = db.get_workspace(&req.workspace_id).map_err(js_error)?;
+            to_json(db.get_or_create_workspace_meta(&workspace.id).map_err(js_error)?)
+        }
+
+        other => Err(js_error(format!("yaak-web: `{other}` is not a command this host answers"))),
+    }
+}
+
+/* -------------------------------------------------------------------------- */
+/* Blobs                                                                       */
+/* -------------------------------------------------------------------------- */
+
+/// The bytes stored under an id, or none. Ids are the desktop's: a response's
+/// own id for its body, `{responseId}.request` for the request that produced
+/// it. Bytes cross to JS as a `Uint8Array` rather than through JSON.
+#[wasm_bindgen]
+pub fn blob_get(id: &str) -> Result<Option<Vec<u8>>> {
+    with_host(|host| {
+        let chunks = host.blobs.connect().get_chunks(id).map_err(js_error)?;
+        if chunks.is_empty() {
+            return Ok(None);
+        }
+        Ok(Some(chunks.into_iter().flat_map(|c| c.data).collect()))
+    })
+}
+
+/// Store bytes under an id, replacing anything already there. Chunked the way
+/// the desktop chunks, so a body written here reads back on a desktop that
+/// imports the database, and vice versa.
+#[wasm_bindgen]
+pub fn blob_put(id: &str, bytes: &[u8]) -> Result<()> {
+    const CHUNK: usize = 512 * 1024;
+    with_host(|host| {
+        let ctx = host.blobs.connect();
+        ctx.delete_chunks(id).map_err(js_error)?;
+        for (i, part) in bytes.chunks(CHUNK).enumerate() {
+            ctx.insert_chunk(&BodyChunk::new(id, i as i32, part.to_vec())).map_err(js_error)?;
+        }
+        Ok(())
+    })
+}
+
+#[wasm_bindgen]
+pub fn blob_delete(id: &str) -> Result<()> {
+    with_host(|host| host.blobs.connect().delete_chunks(id).map_err(js_error))
+}
@@ -1,7 +1,6 @@
 pub mod error;
 pub mod export;
 pub mod import;
-pub mod models_ops;
 pub mod plugin_events;
 pub mod render;
 pub mod send;
@@ -0,0 +1,3 @@
+{
+  "ignorePatterns": "crates/yaak-templates/pkg/**\ncrates/yaak-web/pkg/**\n**/bindings/gen_*.ts\npackage-lock.json\nCargo.lock"
+}
@@ -59,6 +59,7 @@
        "crates-tauri/yaak-fonts",
        "crates-tauri/yaak-license",
        "crates-tauri/yaak-mac-window",
+        "crates/common/yaak-rpc-schema",
        "crates/yaak-crypto",
        "crates/yaak-git",
        "crates/yaak-models",
@@ -66,6 +67,7 @@
        "crates/yaak-sse",
        "crates/yaak-sync",
        "crates/yaak-templates",
+        "crates/yaak-web",
        "crates/yaak-ws",
        "crates-proxy/yaak-proxy-lib",
        "apps/yaak-client",
@@ -290,6 +292,10 @@
      "name": "@yaakapp-internal/mac-window",
      "version": "1.0.0"
    },
+    "crates/common/yaak-rpc-schema": {
+      "name": "@yaakapp-internal/rpc-schema",
+      "version": "1.0.0"
+    },
    "crates/yaak-crypto": {
      "name": "@yaakapp-internal/crypto",
      "version": "1.0.0"
@@ -324,6 +330,13 @@
        "rimraf": "^6.1.2"
      }
    },
+    "crates/yaak-web": {
+      "name": "@yaakapp-internal/web",
+      "version": "1.0.0",
+      "devDependencies": {
+        "rimraf": "^6.1.2"
+      }
+    },
    "crates/yaak-ws": {
      "name": "@yaakapp-internal/ws",
      "version": "1.0.0"
@@ -5753,6 +5766,10 @@
      "resolved": "crates-proxy/yaak-proxy-lib",
      "link": true
    },
+    "node_modules/@yaakapp-internal/rpc-schema": {
+      "resolved": "crates/common/yaak-rpc-schema",
+      "link": true
+    },
    "node_modules/@yaakapp-internal/sse": {
      "resolved": "crates/yaak-sse",
      "link": true
@@ -5785,6 +5802,10 @@
      "resolved": "packages/ui",
      "link": true
    },
+    "node_modules/@yaakapp-internal/web": {
+      "resolved": "crates/yaak-web",
+      "link": true
+    },
    "node_modules/@yaakapp-internal/ws": {
      "resolved": "crates/yaak-ws",
      "link": true
@@ -17189,7 +17210,8 @@
        "@tauri-apps/plugin-dialog": "^2.7.1",
        "@tauri-apps/plugin-fs": "^2.5.1",
        "@tauri-apps/plugin-opener": "^2.5.4",
-        "@tauri-apps/plugin-os": "^2.3.2"
+        "@tauri-apps/plugin-os": "^2.3.2",
+        "@yaakapp-internal/rpc-schema": "^1.0.0"
      }
    },
    "packages/plugin-runtime": {
@@ -66,6 +66,7 @@
    "crates/yaak-sse",
    "crates/yaak-sync",
    "crates/yaak-templates",
+    "crates/yaak-web",
    "crates/yaak-ws",
    "crates-proxy/yaak-proxy-lib",
    "apps/yaak-client",
@@ -9,6 +9,8 @@
    "lint": "tsc --noEmit"
  },
  "dependencies": {
+    "@yaakapp-internal/rpc-schema": "^1.0.0",
+    "@yaakapp-internal/web": "^1.0.0",
    "@tauri-apps/api": "^2.11.0",
    "@tauri-apps/plugin-clipboard-manager": "^2.3.2",
    "@tauri-apps/plugin-dialog": "^2.7.1",
@@ -1,13 +1,13 @@
 import { setPlatform } from "./registry";
 import { createTauriPlatform } from "./tauri";

-// Desktop is the only host today, so it is installed unconditionally and
-// synchronously — several modules call commands while the module graph is still
-// evaluating, so there is no later moment to do this in.
+// The desktop entry. Installed unconditionally and synchronously — several
+// modules call commands while the module graph is still evaluating, so there is
+// no later moment to do this in.
 //
-// This line is the swap point. A browser build selects its own host here, and
-// because nothing else in the app imports a host directly, that is the whole
-// change.
+// This line is the swap point, and a browser build swaps it by resolving the
+// package to `index.web.ts` instead of this file. Because nothing else in the
+// app imports a host directly, that is the whole change.
 setPlatform(createTauriPlatform());

 export * from "./capabilities";
@@ -0,0 +1,23 @@
+import { setPlatform } from "./registry";
+import { createWebPlatform } from "./web";
+
+/**
+ * The package entry for browser builds, selected by aliasing
+ * `@yaakapp-internal/platform` to this file (see `YAAK_TARGET=web` in the
+ * client's vite.config.ts).
+ *
+ * A separate entry rather than a branch inside `index.ts`, because a branch
+ * would still leave `import "@tauri-apps/api"` in the module graph: the folded
+ * `if` disappears, but the imports it guarded do not, and those modules cannot
+ * be proven side-effect free. Splitting the entry means a web build never
+ * mentions Tauri at all — and it keeps `index.ts` exactly as the desktop has
+ * always had it.
+ *
+ * Like `index.ts`, this must install the host eagerly and synchronously:
+ * boot-time modules call commands while the module graph is still evaluating.
+ */
+setPlatform(createWebPlatform());
+
+export * from "./capabilities";
+export { platform, setPlatform } from "./registry";
+export * from "./types";
@@ -0,0 +1,193 @@
+# The browser host
+
+Yaak running in a plain tab: no install, no local process. The desktop's own
+model layer — `yaak-models`, SQLite included — runs compiled to wasm inside a
+worker the tab talks to, so a browser stores exactly what a desktop install
+stores, migrations and all.
+
+Select it at build time and run the frontend alone:
+
+```shell
+YAAK_TARGET=web npm run dev --workspace @yaakapp/yaak-client
+```
+
+The flag resolves `@yaakapp-internal/platform` to `../index.web.ts`, which
+installs this host instead of the Tauri one. It is a separate entry rather than
+a branch inside `index.ts` so that a web build never pulls `@tauri-apps/*` into
+the module graph at all — a folded branch would drop the code but keep the
+imports it guarded.
+
+Desktop builds are untouched: without the flag, `packages/platform/src/index.ts`
+installs the Tauri host exactly as before.
+
+## How it fits together
+
+```
+tab (index.ts, commands.ts) ──MessagePort──▶ worker.ts ──▶ @yaakapp-internal/web (wasm)
+                            ◀── model_writes ──          crates/yaak-web → yaak-models → SQLite
+                                                                        └─ pages in IndexedDB
+```
+
+| File | What it is |
+| --- | --- |
+| `index.ts` | The `Platform` implementation. |
+| `commands.ts` | The command table: model commands forward to the worker; the rest is fixed answers and refusals-with-a-reason. |
+| `connection.ts` | A tab's end of the wire: request/response over a `MessagePort`, event delivery, and the tab's identity (`label`). |
+| `worker.ts` | The process that owns the database. Loads the wasm, opens the DB once, answers each port, fans `model_writes` out to every port. |
+| `protocol.ts` | The message shapes both sides import. |
+| `errors.ts` | `UnsupportedCommandError`, the structured refusal. |
+| `storage.ts` | `navigator.storage.persist()`. |
+
+The Rust side is `crates/yaak-web` (`@yaakapp-internal/web`): `boot()`,
+`rpc(cmd, payload, label)` returning `{ result, events }`, and blob get/put.
+Its `pkg/` is committed; rebuilding needs a clang with a WebAssembly backend
+(`brew install llvm`), and `build-wasm.cjs` skips with a notice when there
+isn't one, so a desktop `npm run bootstrap` never depends on it.
+
+Behaviours worth knowing before changing anything:
+
+- **The worker is a `SharedWorker`, and only that.** The browser hands every
+  tab on the origin the same one, which is what makes "one database owner"
+  true without anyone coordinating — and makes the browser look like the
+  desktop: one process holds the data, every window talks to it, it pushes
+  writes to all of them. It still takes a Web Lock before opening, for the one
+  overlap the browser doesn't rule out (a reloading tab's dying predecessor).
+  There is deliberately no fallback to a per-tab worker: two kinds of worker
+  that can both come up is a race. Every current browser, desktop and mobile,
+  has `SharedWorker` and Web Locks (Chrome for Android since 148, April 2026);
+  older ones get a clear "unsupported browser" message rather than a second
+  SQLite over the same pages.
+- **Every write is stamped with the calling tab's `label`** as
+  `UpdateSource::Window`, exactly like a desktop window label, so the frontend
+  store's echo handling is unchanged.
+- **Cascade rules, duplicate naming, id generation, serde defaults, and the
+  lazy first-run bootstrap are all the Rust code's.** Nothing about what a
+  model *is* is decided in TypeScript.
+- **Persistence is `relaxed-idb`**: SQLite pages live in IndexedDB, writes land
+  in memory and flush shortly after. A tab closing mid-flush loses at most the
+  last few writes.
+
+## Commands
+
+109 commands are declared in `@yaakapp-internal/rpc-schema`. This host answers
+31, declines 44 by name with a reason, and refuses the remaining 34 generically.
+
+### Implemented (31)
+
+| Group | Commands |
+| --- | --- |
+| Models | `models_workspace_models`, `models_upsert`, `models_delete`, `models_duplicate`, `models_get_settings`, `models_get_graphql_introspection`, `models_upsert_graphql_introspection`, `models_grpc_events`, `models_websocket_events` |
+| App | `cmd_metadata`, `cmd_get_workspace_meta`, `cmd_default_headers`, `cmd_get_themes`, `cmd_check_for_updates`, `cmd_dismiss_notification`, `cmd_plugin_init_errors` |
+| Bodies | `cmd_http_response_body`, `cmd_http_response_body_path`, `cmd_http_request_body`, `cmd_get_http_response_events`, `cmd_get_sse_events` |
+| Plugin surfaces (empty results) | `cmd_http_request_actions`, `cmd_websocket_request_actions`, `cmd_grpc_request_actions`, `cmd_workspace_actions`, `cmd_folder_actions`, `cmd_template_function_summaries`, `cmd_get_http_authentication_summaries`, `cmd_get_http_authentication_config` |
+| Text | `cmd_format_json`, `cmd_render_template` |
+
+Some of these answer honestly rather than fully, and the difference matters:
+
+- `cmd_render_template` returns the template **unrendered**. Resolving variables
+  and calling template functions is plugin work. The preview shows the raw
+  `${[…]}` rather than a wrong value.
+- `cmd_get_http_authentication_summaries` returns the auth methods Yaak ships as
+  plugins, so the picker is truthful about the product — but
+  `cmd_get_http_authentication_config` returns an empty form, because the plugin
+  that defines the form isn't running.
+- `cmd_template_function_summaries` returns one provider contributing no
+  functions. Both summary commands are polled every second until they return
+  something, so an empty list is a poll that never stops rather than a quiet no.
+- `cmd_metadata` reports empty strings for the data, log, plugin and project
+  directories. There is no filesystem behind this host.
+
+### Declined by name (44)
+
+Each returns an `UnsupportedCommandError` carrying `cmd`, a user-facing
+`message`, and the `capability` a caller should have checked. The UI turns it
+into a toast.
+
+| Reason | Commands |
+| --- | --- |
+| Sending isn't available yet (slice 2) | `cmd_send_http_request`, `cmd_send_ephemeral_request`, `cmd_delete_send_history`, `cmd_delete_all_http_responses`, `cmd_import_url` |
+| No plugin runtime | `cmd_reload_plugins`, `cmd_plugin_info`, `cmd_plugins_search`, `cmd_plugins_install`, `cmd_plugins_install_from_directory`, `cmd_plugins_uninstall`, `cmd_plugins_updates`, `cmd_plugins_update_all`, `cmd_template_function_config`, `cmd_template_tokens_to_string`, `cmd_call_http_request_action`, `cmd_call_websocket_request_action`, `cmd_call_grpc_request_action`, `cmd_call_workspace_action`, `cmd_call_folder_action`, `cmd_call_http_authentication_action`, `cmd_curl_to_request`, `cmd_format_graphql` |
+| No filesystem | `cmd_import_data`, `cmd_export_data`, `cmd_save_response`, `cmd_save_base64_to_binary` |
+| Needs a real socket | `cmd_grpc_reflect`, `cmd_grpc_go`, `cmd_delete_all_grpc_connections`, `cmd_ws_connect`, `cmd_ws_send`, `cmd_ws_close`, `cmd_ws_delete_connections` |
+| Workspace encryption | `cmd_enable_encryption`, `cmd_disable_encryption`, `cmd_reveal_workspace_key`, `cmd_set_workspace_key`, `cmd_secure_template`, `cmd_decrypt_template` |
+| One tab, no windows | `cmd_new_child_window`, `cmd_new_main_window`, `cmd_restart` |
+| Other | `cmd_send_feedback` |
+
+### Refused generically (34)
+
+The 30 `cmd_git_*` commands and `cmd_sync_calculate`, `cmd_sync_calculate_fs`,
+`cmd_sync_apply`, `cmd_sync_watch`. Nothing in the app reaches them unless a
+workspace has a sync directory, which a browser tab cannot set.
+
+Anything added to the schema later also lands here, and the error names the
+command — an unlisted command is a gap in `commands.ts`, and whoever hits it
+should be able to see which.
+
+## Capabilities
+
+Reported honestly, so callers gate on the question rather than on the host:
+
+| True | False |
+| --- | --- |
+| `cookieJar` (the jar stores and edits here; only filling it needs the sender) | `grpc`, `websocket`, `git`, `sync`, `tlsOptions`, `localFiles`, `timeline`, `multiWindow`, `plugins`, `encryption`, `updater`, `clipboardRead`, `systemFonts`, `license` |
+
+`multiWindow: false` means the host cannot open a *second window* on demand —
+what `cmd_new_child_window` does for Settings and workspace switching. It is not
+a claim that nothing else is looking: other tabs may well be open on the same
+worker, and it pushes every write to all of them regardless.
+
+## Multiple tabs
+
+Each tab mints a label at load (`tab_xxxxxxxx`) and sends it with every command;
+the worker stamps writes with it as `UpdateSource::Window { label }`, standing in
+for the desktop's window label. The worker fans each write out to every
+connected tab, and the receiving tab's store applies or ignores it exactly as a
+desktop window would.
+
+The label is deliberately *not* kept in `sessionStorage`: duplicating a tab
+copies session storage, and two tabs sharing one identity would each mistake the
+other's writes for an echo of their own and drop them.
+
+## Known gaps
+
+- **Storage persistence is requested, not guaranteed.** `navigator.storage.persist()`
+  runs at boot; browsers grant it on their own heuristics and often decline on
+  `localhost`.
+- **`pkg/yaak_web_bg.wasm` is 3.8 MB and committed** (no `wasm-opt`, matching
+  `yaak-templates`). It will churn on every model-layer change; a CI-built
+  artifact is the real answer.
+- **Settings opens in the same tab** and is left with the browser's Back button.
+- **Settings shows Data Directory / Logs Directory rows** with empty values; the
+  Create Workspace dialog offers directory sync and encryption. Should be gated
+  on `localFiles` / `sync` / `encryption`.
+- **`cmd_render_template` returns the template unrendered.** Resolving variables
+  and calling template functions is plugin work.
+- **A declined command logs an unhandled rejection** next to its toast — the
+  app's own `createFastMutation.mutate`, same on desktop.
+- **`yaak-rpc-schema` does not come to wasm** (it pulls the git/gRPC/plugin
+  crates for their types), so the crate declares the handful of request shapes
+  it needs locally, and `commands.ts` stays typed against `RpcSchema`.
+
+## What slice 2 (the send proxy) will need from this layer
+
+Sending becomes a stateless hosted service; this layer stays the only place data
+lives. Concretely:
+
+1. **A rendered request to send.** The client assembles `HttpSendInputs` and
+   posts it. Nothing about the workspace is uploaded except what this request
+   needs.
+2. **Cookies out, cookies in.** The active `cookie_jar` model's `cookies` array
+   goes up with the request; the proxy returns the jar as the exchange left it,
+   and the client upserts it back through `models_upsert` like any other write.
+   The proxy keeps nothing.
+3. **A response body sink.** `blob_put(responseId, bytes)` in the worker
+   writes through the desktop's `blob_manager`, chunked the way it chunks.
+   Streaming will want an append path rather than one whole-body write.
+4. **A request body sink** under `${responseId}.request`, which
+   `cmd_http_request_body` already reads.
+5. **Response and timeline models.** `cmd_send_http_request` currently declines;
+   it will instead upsert an `http_response` as the exchange progresses, plus
+   `http_response_event` rows once `timeline` becomes true. Both flow through
+   the same `write()` helper, so other tabs see a send land live.
+6. **Blob cleanup is the desktop's.** `delete_http_response` and
+   `delete_workspace` in `yaak-models` already remove blob chunks.
@@ -0,0 +1,341 @@
+/**
+ * The command table: what this host answers, and what it declines and why.
+ *
+ * The model commands are forwarded to the worker, where the desktop's own
+ * model layer answers them — same queries, same migrations, same cascade
+ * rules — so nothing about *what a model is* is decided in this file. What is
+ * decided here is the rest of the desktop's command surface: a handful of
+ * fixed answers that are true of a browser tab, and the refusals. The refusals
+ * are the important half: a command that silently returns nothing leaves the
+ * UI showing something that isn't true, whereas a refusal with a reason becomes
+ * a toast the user can act on. So each unsupported command is listed by name
+ * with the reason, and anything not listed at all is refused generically
+ * rather than guessed at.
+ *
+ * The command names are `keyof RpcSchema`, the same generated wire schema the
+ * desktop's router is built from, so a command renamed or added in Rust shows
+ * up here as a type error rather than as a runtime surprise.
+ */
+
+import type { RpcSchema } from "@yaakapp-internal/rpc-schema";
+import type { CapabilityName, RpcPayload } from "../types";
+import type { WorkerConnection } from "./connection";
+import { unsupported } from "./errors";
+
+export type AppCmd = keyof RpcSchema;
+
+type Handler = (payload: RpcPayload, db: WorkerConnection) => Promise<unknown>;
+
+/** Placeholder shown wherever the desktop would show a real filesystem path. */
+const NO_PATH = "";
+
+function str(payload: RpcPayload, key: string): string | null {
+  const value = payload[key];
+  return typeof value === "string" && value !== "" ? value : null;
+}
+
+/** Like `str`, but for fields where an empty string is a legitimate value. */
+function text(payload: RpcPayload, key: string): string {
+  const value = payload[key];
+  return typeof value === "string" ? value : "";
+}
+
+/**
+ * Commands this host answers itself.
+ *
+ * Anything here either reads and writes the browser's own database, or is a
+ * fixed answer that is true of this host — not a stub standing in for something
+ * that should work.
+ */
+const HANDLERS: Partial<Record<AppCmd, Handler>> = {
+  /* ------------------------------- models -------------------------------- */
+
+  // Answered by the model layer itself, in the worker. The payload goes over
+  // untouched and the answer comes back untouched: this file has no opinion
+  // about models, and it would be wrong for it to grow one.
+  models_workspace_models: (payload, db) => db.rpc("models_workspace_models", payload),
+  models_upsert: (payload, db) => db.rpc("models_upsert", payload),
+  models_delete: (payload, db) => db.rpc("models_delete", payload),
+  models_duplicate: (payload, db) => db.rpc("models_duplicate", payload),
+  models_get_settings: (payload, db) => db.rpc("models_get_settings", payload),
+  models_get_graphql_introspection: (payload, db) =>
+    db.rpc("models_get_graphql_introspection", payload),
+  models_upsert_graphql_introspection: (payload, db) =>
+    db.rpc("models_upsert_graphql_introspection", payload),
+  models_grpc_events: (payload, db) => db.rpc("models_grpc_events", payload),
+  models_websocket_events: (payload, db) => db.rpc("models_websocket_events", payload),
+  cmd_get_workspace_meta: (payload, db) => db.rpc("cmd_get_workspace_meta", payload),
+
+  /* -------------------------------- app ---------------------------------- */
+
+  async cmd_metadata() {
+    return {
+      isDev: true,
+      version: "0.0.0-web",
+      cliVersion: null,
+      name: "Yaak",
+      // The desktop hands out real directories here and the UI offers to open
+      // them. There is no filesystem behind this host, and the capability flags
+      // are what the UI should be gating those affordances on.
+      appDataDir: NO_PATH,
+      appLogDir: NO_PATH,
+      vendoredPluginDir: NO_PATH,
+      defaultProjectDir: NO_PATH,
+      featureUpdater: false,
+      featureLicense: false,
+    };
+  },
+
+  // The theme package ships its own defaults, so an empty list is a complete
+  // answer rather than a degraded one — themes beyond those come from plugins.
+  async cmd_get_themes() {
+    return [];
+  },
+
+  async cmd_default_headers() {
+    // Mirrors `default_headers()` in crates/yaak-models/src/queries/workspaces.rs
+    return [
+      { enabled: true, name: "User-Agent", value: "yaak", id: null },
+      { enabled: true, name: "Accept", value: "*/*", id: null },
+    ];
+  },
+
+  async cmd_plugin_init_errors() {
+    return [];
+  },
+
+  async cmd_check_for_updates() {
+    return false;
+  },
+
+  async cmd_dismiss_notification() {
+    return null;
+  },
+
+  // Plugin-contributed menus. Empty is honest: no plugin runtime, no actions.
+  async cmd_http_request_actions() {
+    return [];
+  },
+  async cmd_websocket_request_actions() {
+    return [];
+  },
+  async cmd_grpc_request_actions() {
+    return [];
+  },
+  async cmd_workspace_actions() {
+    return [];
+  },
+  async cmd_folder_actions() {
+    return [];
+  },
+
+  /**
+   * Both of these are polled once a second until they answer with something, so
+   * an empty list is not a quiet no — it is a poll that never stops.
+   *
+   * The auth list names what Yaak actually offers, so the picker tells the
+   * truth about the product even though the form behind each entry stays empty
+   * until plugins run here. Template functions get the opposite treatment: one
+   * provider contributing no functions. That settles the poll while putting
+   * nothing in the autocomplete, which is the honest answer — a function the
+   * user could insert but nothing could evaluate would be worse than none.
+   */
+  async cmd_get_http_authentication_summaries() {
+    return HTTP_AUTHENTICATION_SUMMARIES;
+  },
+  async cmd_template_function_summaries() {
+    return [{ pluginRefId: "web", functions: [] }];
+  },
+
+  async cmd_get_http_authentication_config() {
+    return { args: [], pluginRefId: "web" };
+  },
+
+  async cmd_format_json(payload) {
+    const source = text(payload, "text");
+    try {
+      return JSON.stringify(JSON.parse(source), null, 2);
+    } catch {
+      // Formatting invalid JSON is a no-op, not an error: the editor calls this
+      // while the user is still typing.
+      return source;
+    }
+  },
+
+  /**
+   * Rendering resolves variables and calls template functions, and the
+   * functions live in plugins. Handing the template back unrendered is what the
+   * preview then shows — the raw `${[...]}`, which is at least the thing the
+   * user typed rather than a wrong value.
+   */
+  async cmd_render_template(payload) {
+    return text(payload, "template");
+  },
+
+  /* ------------------------------- bodies -------------------------------- */
+
+  async cmd_http_response_body(payload, db) {
+    const responseId = str(payload, "responseId");
+    if (responseId == null) return { content: "" };
+
+    if (str(payload, "filter") != null) {
+      return {
+        content: "",
+        error: "Response filters come from a plugin, which this host doesn't run yet",
+      };
+    }
+
+    const bytes = await db.blobGet(responseId);
+    return { content: bytes == null ? "" : new TextDecoder().decode(bytes) };
+  },
+
+  // Bodies live in this database, not on a disk, so there is no path to give.
+  async cmd_http_response_body_path() {
+    return null;
+  },
+
+  async cmd_http_request_body(payload, db) {
+    const responseId = str(payload, "responseId");
+    if (responseId == null) return null;
+    // Keyed the way the desktop keys it: the request bytes belong to the
+    // response that recorded them.
+    const bytes = await db.blobGet(`${responseId}.request`);
+    return bytes == null ? null : Array.from(bytes);
+  },
+
+  async cmd_get_http_response_events() {
+    return [];
+  },
+
+  async cmd_get_sse_events() {
+    return [];
+  },
+};
+
+/**
+ * The auth methods Yaak ships as plugins today (plugins/auth-*). Listed so the
+ * picker is truthful about the product; choosing one currently yields an empty
+ * config form, because the plugin that defines the form isn't running.
+ */
+const HTTP_AUTHENTICATION_SUMMARIES = [
+  { name: "apikey", label: "API Key", shortLabel: "API Key" },
+  { name: "aws", label: "AWS SigV4", shortLabel: "AWS" },
+  { name: "basic", label: "Basic Auth", shortLabel: "Basic" },
+  { name: "bearer", label: "Bearer Token", shortLabel: "Bearer" },
+  { name: "jwt", label: "JWT Bearer", shortLabel: "JWT" },
+  { name: "ntlm", label: "NTLM", shortLabel: "NTLM" },
+  { name: "oauth1", label: "OAuth 1.0", shortLabel: "OAuth 1" },
+  { name: "oauth2", label: "OAuth 2.0", shortLabel: "OAuth 2" },
+];
+
+/**
+ * Commands this host declines, each with the reason a user would need.
+ *
+ * Naming them individually rather than letting them fall through to a generic
+ * refusal is deliberate: "sending is not available yet" and "Yaak in a browser
+ * has no filesystem" are different situations, and the second is permanent
+ * while the first is a slice away.
+ */
+const DECLINED: Partial<Record<AppCmd, [reason: string, capability: CapabilityName | null]>> = {
+  // Sending — the next slice. Everything else about a request works today;
+  // only the part that puts bytes on the network is missing.
+  cmd_send_http_request: [
+    "Sending isn't available in the browser yet — everything else about this request is saved",
+    null,
+  ],
+  cmd_send_ephemeral_request: [
+    "Sending isn't available in the browser yet — everything else about this request is saved",
+    null,
+  ],
+  cmd_curl_to_request: ["Importing from cURL needs a plugin, which this host doesn't run", null],
+
+  // Protocols that need a real socket.
+  cmd_grpc_reflect: ["gRPC isn't available in the browser", "grpc"],
+  cmd_grpc_go: ["gRPC isn't available in the browser", "grpc"],
+  cmd_delete_all_grpc_connections: ["gRPC isn't available in the browser", "grpc"],
+  cmd_ws_connect: ["WebSocket requests aren't available in the browser yet", "websocket"],
+  cmd_ws_send: ["WebSocket requests aren't available in the browser yet", "websocket"],
+  cmd_ws_close: ["WebSocket requests aren't available in the browser yet", "websocket"],
+  cmd_ws_delete_connections: ["WebSocket requests aren't available in the browser yet", "websocket"],
+
+  // Anything that needs files the page can't reach.
+  cmd_import_data: ["Importing from a file needs a filesystem, which a browser tab has no", "localFiles"],
+  cmd_import_url: ["Importing from a URL needs the send proxy, which isn't available yet", null],
+  cmd_export_data: ["Exporting to a file isn't available in the browser yet", "localFiles"],
+  cmd_save_response: ["Saving a response to disk isn't available in the browser", "localFiles"],
+  cmd_save_base64_to_binary: ["Saving to disk isn't available in the browser", "localFiles"],
+  cmd_format_graphql: ["Formatting GraphQL needs a plugin, which this host doesn't run", null],
+
+  // Windows. A tab is the window, and there is only ever one of it.
+  cmd_new_child_window: ["Yaak in a browser uses one tab", "multiWindow"],
+  cmd_new_main_window: ["Yaak in a browser uses one tab", "multiWindow"],
+  cmd_restart: ["Reload the page to restart Yaak", null],
+
+  // Workspace encryption is backed by a key the host keeps for you; a page has
+  // nowhere to keep one that a page couldn't also read.
+  cmd_enable_encryption: ["Workspace encryption isn't available in the browser", "encryption"],
+  cmd_disable_encryption: ["Workspace encryption isn't available in the browser", "encryption"],
+  cmd_reveal_workspace_key: ["Workspace encryption isn't available in the browser", "encryption"],
+  cmd_set_workspace_key: ["Workspace encryption isn't available in the browser", "encryption"],
+  cmd_secure_template: ["Workspace encryption isn't available in the browser", "encryption"],
+  cmd_decrypt_template: ["Workspace encryption isn't available in the browser", "encryption"],
+
+  // The plugin runtime is a Node process. Nothing here runs one.
+  cmd_reload_plugins: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugin_info: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_search: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_install: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_install_from_directory: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_uninstall: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_updates: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_plugins_update_all: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_template_function_config: ["Template functions come from plugins, which this host doesn't run", "plugins"],
+  cmd_template_tokens_to_string: ["Template functions come from plugins, which this host doesn't run", "plugins"],
+  cmd_call_http_request_action: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_call_websocket_request_action: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_call_grpc_request_action: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_call_workspace_action: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_call_folder_action: ["Plugins aren't available in the browser yet", "plugins"],
+  cmd_call_http_authentication_action: ["Plugins aren't available in the browser yet", "plugins"],
+
+  // Sending history and its bookkeeping belong to the send slice.
+  cmd_delete_send_history: ["Sending isn't available in the browser yet", null],
+  cmd_delete_all_http_responses: ["Sending isn't available in the browser yet", null],
+
+  cmd_send_feedback: ["Feedback goes through the desktop app for now", null],
+};
+
+/**
+ * The support table, for documentation and for the console.
+ *
+ * Derived from the two maps above rather than written alongside them, so it
+ * cannot drift from what the host actually does.
+ */
+export function commandSupport(): {
+  implemented: string[];
+  declined: { cmd: string; reason: string; capability: CapabilityName | null }[];
+} {
+  return {
+    implemented: Object.keys(HANDLERS).sort(),
+    declined: Object.entries(DECLINED)
+      .map(([cmd, [reason, capability]]) => ({ cmd, reason, capability }))
+      .sort((a, b) => a.cmd.localeCompare(b.cmd)),
+  };
+}
+
+export async function runCommand(
+  cmd: string,
+  payload: RpcPayload,
+  db: WorkerConnection,
+): Promise<unknown> {
+  const handler = HANDLERS[cmd as AppCmd];
+  if (handler != null) return handler(payload, db);
+
+  const declined = DECLINED[cmd as AppCmd];
+  if (declined != null) throw unsupported(cmd, declined[0], declined[1]);
+
+  // Git and sync land here, along with anything added to the schema since. The
+  // message names the command because an unlisted one is a gap in this file,
+  // and whoever hits it should be able to see which.
+  throw unsupported(cmd, `\`${cmd}\` isn't available when Yaak runs in a browser`);
+}
@@ -0,0 +1,230 @@
+/**
+ * A tab's end of the wire to the worker that owns the database.
+ *
+ * Constructible synchronously and usable immediately, which is the hard
+ * requirement: boot-time modules call commands while the module graph is still
+ * evaluating, so there is no later moment to connect in. Messages posted before
+ * the worker has opened the database sit in the port until it has, and the
+ * app's own top-level await then doubles as the boot gate — nothing renders
+ * until the first command has answered, and it can only answer once the
+ * database is open.
+ */
+
+import type { Unsubscribe } from "../types";
+import { type FromWorker, type ToWorker, WORKER_NAME } from "./protocol";
+
+/**
+ * How long a freshly connected worker gets to say hello.
+ *
+ * A live worker answers in the same turn it is connected — the worker script
+ * is tiny and imports the model layer lazily, so this measures liveness, not
+ * load time. It only has to be longer than a cold fetch of that small script;
+ * a worker silent past this is not coming, and a message beats a blank page.
+ */
+const HELLO_TIMEOUT_MS = 3000;
+
+const WORKER_FAILED = "Yaak's database worker could not be started. Reload the page to try again";
+
+const UNSUPPORTED =
+  "This browser can't run Yaak: it needs shared workers and Web Locks to keep your data safe across tabs. Every current browser has both.";
+
+type Pending = { resolve: (value: unknown) => void; reject: (reason: Error) => void };
+
+export class WorkerConnection {
+  private port: MessagePort | null;
+  private readonly pending = new Map<number, Pending>();
+  private readonly listeners = new Map<string, Set<(payload: unknown) => void>>();
+  private nextId = 1;
+  private bootError: string | null = null;
+
+  /**
+   * This tab's identity, standing in for the desktop's window label. Stamped
+   * on every write this tab makes, so the store can tell an echo of its own
+   * write from another tab's. Minted per page load, not kept in
+   * `sessionStorage`, on purpose: duplicating a tab copies session storage,
+   * and two tabs claiming one identity would each drop the other's writes as
+   * echoes.
+   */
+  readonly label = `tab_${crypto.randomUUID().slice(0, 8)}`;
+
+  /** True once the worker has said anything at all. */
+  private heard = false;
+
+  constructor() {
+    // Both are required and neither is faked. Without a shared worker every
+    // tab would need its own SQLite over the same pages; without Web Locks
+    // nothing can promise there is only one even so. Every current browser,
+    // desktop and mobile, has both (Chrome for Android since 148); the ones
+    // that don't get told, not corrupted.
+    if (typeof SharedWorker === "undefined" || typeof navigator.locks === "undefined") {
+      this.port = null;
+      this.bootError = UNSUPPORTED;
+      showBootError(UNSUPPORTED);
+      return;
+    }
+
+    this.port = this.connect();
+
+    // Let the worker forget this port. Not load-bearing — a port that never
+    // says goodbye is a leaked entry in a Set — but tidy.
+    window.addEventListener("pagehide", () => this.post({ type: "goodbye" }));
+  }
+
+  /**
+   * Connect to the origin's one database worker.
+   *
+   * The browser hands every tab the same SharedWorker for this name and URL,
+   * which is what makes "one database owner" true without anyone coordinating.
+   *
+   * `new URL("./worker.ts", import.meta.url)` is written out inline on purpose:
+   * that exact syntax is what the bundler pattern-matches to know it must
+   * bundle a worker entry. Hoisted into a variable it becomes an asset URL and
+   * ships as raw TypeScript.
+   */
+  private connect(): MessagePort {
+    const worker = new SharedWorker(new URL("./worker.ts", import.meta.url), {
+      type: "module",
+      name: WORKER_NAME,
+    });
+    // A worker whose script fails to load fires `error` on the SharedWorker
+    // object and nothing else — the port just goes quiet.
+    worker.onerror = () => {
+      if (!this.heard) this.failEverything(`${WORKER_FAILED} (its script failed to load).`);
+    };
+    worker.port.onmessage = (e: MessageEvent<FromWorker>) => this.receive(e.data);
+    worker.port.start();
+
+    // The worker says hello synchronously on connect. Silence past the timeout
+    // means this port is attached to nothing that will ever answer, and the
+    // user should see that rather than a blank page. It is not retried: the
+    // one way this used to happen (a module worker missing connects during a
+    // top-level-await import) is fixed at the source by importing the wasm
+    // lazily, and a reload is the right remedy for anything else.
+    setTimeout(() => {
+      if (!this.heard) this.failEverything(`${WORKER_FAILED} (it never answered).`);
+    }, HELLO_TIMEOUT_MS);
+
+    return worker.port;
+  }
+
+  private failEverything(message: string): void {
+    this.bootError = message;
+    showBootError(message);
+    for (const [id, p] of this.pending) {
+      this.pending.delete(id);
+      p.reject(new Error(message));
+    }
+  }
+
+  private post(message: ToWorker, transfer: Transferable[] = []): void {
+    this.port?.postMessage(message, transfer);
+  }
+
+  private receive(message: FromWorker): void {
+    this.heard = true;
+    switch (message.type) {
+      case "hello":
+      case "ready":
+        return;
+      case "boot_error":
+        // Nothing will ever answer, and the app cannot render without an
+        // answer, so say what happened where the user can see it. This is the
+        // page's whole content at this point.
+        this.failEverything(message.message);
+        return;
+      case "result": {
+        const p = this.pending.get(message.id);
+        this.pending.delete(message.id);
+        p?.resolve(message.result);
+        return;
+      }
+      case "error": {
+        const p = this.pending.get(message.id);
+        this.pending.delete(message.id);
+        p?.reject(new Error(message.message));
+        return;
+      }
+      case "event":
+        this.deliver(message.event, message.payload);
+        return;
+    }
+  }
+
+  private request<T>(build: (id: number) => ToWorker, transfer: Transferable[] = []): Promise<T> {
+    if (this.bootError != null) return Promise.reject(new Error(this.bootError));
+    const id = this.nextId++;
+    return new Promise<T>((resolve, reject) => {
+      this.pending.set(id, { resolve: resolve as (v: unknown) => void, reject });
+      this.post(build(id), transfer);
+    });
+  }
+
+  rpc<T>(cmd: string, payload: unknown): Promise<T> {
+    return this.request<T>((id) => ({ type: "rpc", id, cmd, payload, label: this.label }));
+  }
+
+  async blobGet(blobId: string): Promise<Uint8Array<ArrayBuffer> | null> {
+    const buf = await this.request<ArrayBuffer | null>((id) => ({ type: "blob_get", id, blobId }));
+    return buf == null ? null : new Uint8Array(buf);
+  }
+
+  blobPut(blobId: string, bytes: Uint8Array): Promise<void> {
+    // Copied so the caller's buffer isn't detached out from under it, then
+    // transferred so the copy isn't copied again crossing to the worker.
+    const copy = new Uint8Array(bytes.byteLength);
+    copy.set(bytes);
+    return this.request<void>(
+      (id) => ({ type: "blob_put", id, blobId, bytes: copy.buffer }),
+      [copy.buffer],
+    );
+  }
+
+  blobDelete(blobId: string): Promise<void> {
+    return this.request<void>((id) => ({ type: "blob_delete", id, blobId }));
+  }
+
+  /* ------------------------------- events -------------------------------- */
+
+  listen(event: string, callback: (payload: unknown) => void): Unsubscribe {
+    let set = this.listeners.get(event);
+    if (set == null) {
+      set = new Set();
+      this.listeners.set(event, set);
+    }
+    set.add(callback);
+    return () => {
+      set.delete(callback);
+      if (set.size === 0) this.listeners.delete(event);
+    };
+  }
+
+  /**
+   * Deliver an event to this tab's listeners.
+   *
+   * Used for what the worker pushes, and for the app's own local emits (a
+   * plugin round trip, a stream teardown). Local emits stay local: every
+   * emitter in the app is replying to something *this* tab is doing.
+   */
+  deliver(event: string, payload: unknown): void {
+    const set = this.listeners.get(event);
+    if (set == null) return;
+    // Copied because a listener may unsubscribe itself while being called
+    for (const callback of Array.from(set)) {
+      try {
+        callback(payload);
+      } catch (err) {
+        console.error(`Listener for \`${event}\` threw`, err);
+      }
+    }
+  }
+}
+
+function showBootError(message: string): void {
+  const root = document.getElementById("root");
+  if (root == null || root.childElementCount > 0) return;
+  const el = document.createElement("div");
+  el.style.cssText =
+    "font: 15px/1.5 system-ui, sans-serif; max-width: 32rem; margin: 20vh auto; padding: 0 1rem; color: inherit";
+  el.textContent = message;
+  root.appendChild(el);
+}
@@ -0,0 +1,32 @@
+import type { CapabilityName } from "../types";
+
+/**
+ * What this host says when it is asked for something it doesn't have.
+ *
+ * A rejected command reaches the user as a toast built from `message`, so the
+ * message is the user-facing text and has to read like one. The structured
+ * fields alongside it are for code: `capability` names the switch a caller
+ * should have checked first, and `cmd` identifies the command without anyone
+ * having to parse prose back out of the message.
+ */
+export class UnsupportedCommandError extends Error {
+  readonly name = "UnsupportedCommandError";
+  /** Stable discriminator, so a caller can branch without matching on text. */
+  readonly code = "unsupported_command";
+  readonly cmd: string;
+  readonly capability: CapabilityName | null;
+
+  constructor(cmd: string, message: string, capability: CapabilityName | null = null) {
+    super(message);
+    this.cmd = cmd;
+    this.capability = capability;
+  }
+}
+
+export function unsupported(
+  cmd: string,
+  reason: string,
+  capability: CapabilityName | null = null,
+): UnsupportedCommandError {
+  return new UnsupportedCommandError(cmd, reason, capability);
+}
@@ -0,0 +1,264 @@
+/**
+ * The browser host: Yaak in a tab, with no install and nothing running locally.
+ *
+ * The desktop host forwards to a Rust process. This one forwards to a worker
+ * running the same model layer compiled to wasm, over a `MessagePort` instead
+ * of Tauri's IPC. The worker owns the database and is shared by every tab on
+ * the origin, so two tabs stay coherent for the same reason two desktop windows
+ * do: one process holds the data and pushes every write to all of them.
+ *
+ * What a page genuinely cannot do is not faked. There is no file dialog, no
+ * second window, no clipboard read without a prompt, and — in this slice — no
+ * sending. Those report false through `capabilities` and refuse with a reason
+ * if called anyway, so a missing feature shows up as a disabled control or a
+ * toast that explains itself, never as a silent no-op.
+ */
+
+import type {
+  DragDropEvent,
+  OsType,
+  Platform,
+  PlatformCapabilities,
+  PlatformWindow,
+  RpcPayload,
+  RpcStreamHandle,
+  Unsubscribe,
+} from "../types";
+import { commandSupport, runCommand } from "./commands";
+import { WorkerConnection } from "./connection";
+import { unsupported } from "./errors";
+import { requestPersistence } from "./storage";
+
+/** What this host can do, reported honestly. */
+function capabilitiesFor(): PlatformCapabilities {
+  return {
+    grpc: false,
+    websocket: false,
+    git: false,
+    sync: false,
+    // Certificates and proxies are decided by whoever puts the bytes on the
+    // wire. Nothing in the browser does yet.
+    tlsOptions: false,
+    // The jar can be edited and stored here; only filling it needs the sender.
+    cookieJar: true,
+    localFiles: false,
+    timeline: false,
+    // Whether the host can put a *second window* on this data on demand — what
+    // `cmd_new_child_window` does for Settings and workspace switching. A tab
+    // can't, so those open in place instead. This is not a claim that nothing
+    // else is looking: other tabs may well be open on the same worker, and it
+    // pushes every write to all of them regardless of this flag.
+    multiWindow: false,
+    plugins: false,
+    encryption: false,
+    updater: false,
+    // Reading needs a permission prompt at first paint, which is a bad ask for
+    // an app people paste bearer tokens into. Pasting still works everywhere.
+    clipboardRead: false,
+    systemFonts: false,
+    license: false,
+  };
+}
+
+/** Match `@tauri-apps/plugin-os` spellings so layout code needs no new branch. */
+function detectOsType(): OsType {
+  const ua = navigator.userAgent;
+  if (/Mac|iPhone|iPad|iPod/.test(ua)) return "macos";
+  if (/Win/.test(ua)) return "windows";
+  if (/Android/.test(ua)) return "android";
+  return "linux";
+}
+
+/**
+ * The Tauri host-plugin commands, which ride outside the RPC envelope.
+ *
+ * `set_title` has a real browser equivalent. `set_theme` paints the native
+ * window frame behind the webview, which a tab has neither of. The license and
+ * font plugins answer with "nothing", which is true and keeps the settings
+ * screens rendering instead of erroring.
+ */
+async function hostPluginCommand<T>(cmd: string, payload?: RpcPayload): Promise<T> {
+  switch (cmd) {
+    case "plugin:yaak-mac-window|set_title": {
+      const title = payload?.title;
+      document.title = typeof title === "string" ? title : "Yaak";
+      return undefined as T;
+    }
+    case "plugin:yaak-mac-window|set_theme":
+      return undefined as T;
+    case "plugin:yaak-fonts|list":
+      // Enumerating installed fonts is a fingerprinting surface browsers don't
+      // offer. The pickers fall back to their bundled families.
+      return { editorFonts: [], uiFonts: [] } as T;
+    default:
+      throw unsupported(cmd, `\`${cmd}\` isn't available when Yaak runs in a browser`);
+  }
+}
+
+function createWindow(db: WorkerConnection): PlatformWindow {
+  const noop = async () => {};
+
+  return {
+    // Stands in for the desktop's window label: the identity model writes carry
+    // so a tab can tell its own echo from another tab's write.
+    label: db.label,
+
+    // A tab manages its own frame. These exist because the interface names
+    // them; the UI only reaches for them behind `multiWindow`.
+    show: noop,
+    close: noop,
+    minimize: noop,
+    maximize: noop,
+    unmaximize: noop,
+    isMaximized: async () => false,
+    isFullscreen: async () => document.fullscreenElement != null,
+    setZoom: noop,
+
+    // Null means "no opinion, let CSS decide". The desktop returns a real value
+    // because applying a theme forces the window appearance and poisons the
+    // media query; nothing does that here, so `prefers-color-scheme` is the
+    // honest answer and the theme package already falls back to it.
+    theme: async () => null,
+
+    onThemeChanged(callback) {
+      const media = window.matchMedia("(prefers-color-scheme: dark)");
+      const listener = () => callback(media.matches ? "dark" : "light");
+      media.addEventListener("change", listener);
+      return () => media.removeEventListener("change", listener);
+    },
+
+    onFocusChanged(callback) {
+      const onFocus = () => callback(true);
+      const onBlur = () => callback(false);
+      window.addEventListener("focus", onFocus);
+      window.addEventListener("blur", onBlur);
+      return () => {
+        window.removeEventListener("focus", onFocus);
+        window.removeEventListener("blur", onBlur);
+      };
+    },
+
+    // Native drag-and-drop reports OS paths, which a page never sees. The DOM's
+    // own drag events are a different thing, and the components that need those
+    // use them directly.
+    onDragDrop(_callback: (event: DragDropEvent) => void): Unsubscribe {
+      return () => {};
+    },
+  };
+}
+
+export function createWebPlatform(): Platform {
+  const db = new WorkerConnection();
+  const capabilities = capabilitiesFor();
+
+  // Without this, IndexedDB is best-effort storage and a browser reclaiming
+  // space may drop someone's workspaces. Asking is all we can do, and there is
+  // nothing useful to do about a refusal.
+  void requestPersistence();
+
+  // Enough to answer "what does this host actually do?" from the console
+  // without reading the source.
+  (window as unknown as Record<string, unknown>).__YAAK_WEB__ = {
+    label: db.label,
+    capabilities,
+    commands: commandSupport,
+  };
+
+  return {
+    capabilities,
+    window: createWindow(db),
+
+    clipboard: {
+      writeText: (text) => navigator.clipboard.writeText(text),
+      readText: async () => {
+        throw unsupported("clipboard.readText", "Paste instead — Yaak in a browser can't read the clipboard on its own", "clipboardRead");
+      },
+      clear: async () => {
+        throw unsupported("clipboard.clear", "Yaak in a browser can't modify the clipboard", "clipboardRead");
+      },
+    },
+
+    // Returning null rather than throwing: null is what a cancelled dialog
+    // returns, which every caller already handles.
+    dialog: {
+      open: (async () => null) as Platform["dialog"]["open"],
+      save: async () => null,
+    },
+
+    files: {
+      readDir: async () => {
+        throw unsupported("files.readDir", "A browser tab can't browse your filesystem", "localFiles");
+      },
+      readText: async () => {
+        throw unsupported("files.readText", "A browser tab can't read local files", "localFiles");
+      },
+      // No filesystem here, so a path is just a string this host echoes back.
+      url: (path) => path,
+      basename: async (path) => path.split(/[/\\]/).pop() ?? path,
+      resolveResource: async (path) => path,
+    },
+
+    /**
+     * Bodies live in the worker's blob database, addressed by the id they were
+     * stored under. A page hands over an id and never a location, which is what
+     * keeps it from naming bytes the app never wrote.
+     */
+    blobs: {
+      read: (id) => db.blobGet(id),
+
+      async url(id) {
+        const bytes = await db.blobGet(id);
+        // An object URL, the tab's equivalent of Tauri's `convertFileSrc`. The
+        // caller keys a query on it and drops it on the next response, so it is
+        // left to be reclaimed when the document goes rather than revoked here
+        // while an <img> may still be loading it.
+        return bytes == null ? null : URL.createObjectURL(new Blob([bytes]));
+      },
+    },
+
+    rpc<T>(cmd: string, payload?: RpcPayload): Promise<T> {
+      // `plugin:` commands are Tauri host plugins, not engine commands, and
+      // never reached the router even on the desktop.
+      if (cmd.startsWith("plugin:")) return hostPluginCommand<T>(cmd, payload);
+      return runCommand(cmd, payload ?? {}, db) as Promise<T>;
+    },
+
+    async rpcStream<T, M>(
+      cmd: string,
+      payload: RpcPayload,
+      onMessage: (message: M) => void,
+    ): Promise<RpcStreamHandle<T>> {
+      // Same shape as the desktop — subscribe first, then dispatch — so that a
+      // command which grows the ability to stream here needs no caller changes.
+      const streamId = crypto.randomUUID();
+      const unlisten = db.listen(`stream_${streamId}`, (p) => onMessage(p as M));
+      try {
+        const result = (await runCommand(cmd, { ...payload, streamId }, db)) as T;
+        return { result, unlisten };
+      } catch (err) {
+        unlisten();
+        throw err;
+      }
+    },
+
+    listen<T>(event: string, callback: (payload: T) => void): Unsubscribe {
+      return db.listen(event, (payload) => callback(payload as T));
+    },
+
+    // Local only. Every emitter in the app is replying to something this tab is
+    // doing — a plugin round trip, a stream teardown — and telling other tabs
+    // about it would answer a question they never asked.
+    emit: async (event, payload) => db.deliver(event, payload),
+
+    openUrl: async (url) => {
+      window.open(url, "_blank", "noopener,noreferrer");
+    },
+
+    revealItemInDir: async () => {
+      throw unsupported("revealItemInDir", "A browser tab can't open your file manager", "localFiles");
+    },
+
+    osType: detectOsType,
+    appIdentifier: async () => "app.yaak.web",
+  };
+}
@@ -0,0 +1,47 @@
+/**
+ * The messages that cross between a tab and the worker that owns the database.
+ *
+ * Declared once and imported from both sides, so a change to the shape is a
+ * type error in whichever side forgot. Kept deliberately small: commands in,
+ * results or errors out, and events pushed the other way — the same envelope
+ * the desktop's IPC uses, because that is what the frontend is written against.
+ */
+
+/** Tab → worker */
+export type ToWorker =
+  | { type: "rpc"; id: number; cmd: string; payload: unknown; label: string }
+  | { type: "blob_get"; id: number; blobId: string }
+  | { type: "blob_put"; id: number; blobId: string; bytes: ArrayBuffer }
+  | { type: "blob_delete"; id: number; blobId: string }
+  /** The tab is going away; the worker can forget its port. */
+  | { type: "goodbye" };
+
+/** Worker → tab */
+export type FromWorker =
+  /**
+   * Sent synchronously the moment a port connects, before anything else. Its
+   * only job is to prove the worker is alive: a tab that connects during a
+   * shared worker's teardown gets a port that is accepted and then never
+   * serviced, and this is how it tells that apart from a slow boot.
+   */
+  | { type: "hello" }
+  /** The database is open. Sent to each port once boot has finished. */
+  | { type: "ready" }
+  /** The database could not be opened; every command will fail with this. */
+  | { type: "boot_error"; message: string }
+  | { type: "result"; id: number; result: unknown }
+  | { type: "error"; id: number; message: string }
+  /** A backend event for the app — today only `model_writes`. Sent to every port. */
+  | { type: "event"; event: string; payload: unknown };
+
+/** What the worker registers itself under. Tabs on one origin share it. */
+export const WORKER_NAME = "yaak-db";
+
+/**
+ * The Web Lock the worker takes before opening the database.
+ *
+ * The browser already guarantees one SharedWorker per origin for this name.
+ * The lock covers the one overlap it doesn't rule out: a tab reloading itself,
+ * whose old worker may still be letting go while the new one comes up.
+ */
+export const DB_LOCK_NAME = "yaak-db";
@@ -0,0 +1,18 @@
+/**
+ * Ask the browser not to evict this origin's data under storage pressure.
+ *
+ * Without it IndexedDB — where the worker's SQLite pages live — is "best
+ * effort", and a browser clearing space can drop a user's workspaces. Granting
+ * is the browser's call; it typically says yes once a site looks installed or
+ * engaged, and often says no on localhost. This is a request, not a guarantee,
+ * and there is nothing useful to do when it declines.
+ */
+export async function requestPersistence(): Promise<boolean> {
+  try {
+    if (navigator.storage?.persist == null) return false;
+    if (await navigator.storage.persisted()) return true;
+    return await navigator.storage.persist();
+  } catch {
+    return false;
+  }
+}
@@ -0,0 +1,191 @@
+/// <reference lib="webworker" />
+
+/**
+ * The process that owns the database.
+ *
+ * On the desktop that is the Rust binary: it holds SQLite, every window talks
+ * to it, and it pushes model writes to all of them. In a browser this worker
+ * plays that part. It loads the model layer compiled to wasm, opens the one
+ * database, answers each tab's commands over its port, and fans every
+ * `model_writes` out to every port — so two tabs are coherent for the same
+ * reason two desktop windows are, not because of a side channel.
+ *
+ * It is a SharedWorker, and only that: the browser hands every tab on the
+ * origin the same one, which is what makes "one database owner" true without
+ * anyone coordinating. It still takes a Web Lock before opening the database,
+ * for the one overlap the browser doesn't rule out — a tab reloading itself,
+ * whose old worker may still be letting go while the new one comes up.
+ */
+
+import { DB_LOCK_NAME, type FromWorker, type ToWorker } from "./protocol";
+
+/**
+ * The wasm is imported lazily, inside `boot()`, rather than at the top of the
+ * module. That keeps this script's own evaluation instant, so a tab's connect
+ * gets its `hello` immediately regardless of how long the model layer takes to
+ * download and compile — and the tab can therefore tell "this worker is dead"
+ * from "this worker is busy" with a short timeout.
+ */
+type Engine = typeof import("@yaakapp-internal/web");
+let engine: Engine | null = null;
+
+const ports = new Set<MessagePort>();
+
+/** Resolves once `boot()` has, or rejects with why it couldn't. */
+let booted: Promise<void> | null = null;
+let bootError: string | null = null;
+
+function send(port: MessagePort, message: FromWorker, transfer: Transferable[] = []): void {
+  port.postMessage(message, transfer);
+}
+
+function broadcast(message: FromWorker): void {
+  for (const port of ports) send(port, message);
+}
+
+function errorMessage(err: unknown): string {
+  if (err instanceof Error) return err.message;
+  return String(err);
+}
+
+/**
+ * How long to wait for the database lock before concluding someone else has it
+ * for good. The wait exists for one case: a tab reloading itself. Its old
+ * worker still holds the lock while it is torn down, and the new worker only
+ * needs it to let go — which takes milliseconds, not seconds. Anything longer
+ * is a live worker in another tab, and the honest answer is to say so.
+ */
+const LOCK_TIMEOUT_MS = 3000;
+
+const ALREADY_OPEN =
+  "Yaak's database is held by another worker that isn't letting go. Close Yaak's other tabs and reload.";
+
+/**
+ * Take the lock, or explain why not.
+ *
+ * Held for the life of the worker: the callback's promise never settles, so
+ * the browser keeps the lock until this worker is gone. Requested with a
+ * timeout rather than `ifAvailable`, so a dying predecessor's brief hold is
+ * waited out but a live one is reported.
+ */
+function acquireDatabaseLock(): Promise<void> {
+  // The tab checked for Web Locks before it ever connected; a worker without
+  // them would be a browser lying about its own features.
+  return new Promise<void>((resolve, reject) => {
+    navigator.locks
+      .request(DB_LOCK_NAME, { signal: AbortSignal.timeout(LOCK_TIMEOUT_MS) }, () => {
+        resolve();
+        return new Promise<void>(() => {});
+      })
+      .catch((err: unknown) => {
+        const name = (err as { name?: string } | null)?.name;
+        reject(name === "AbortError" || name === "TimeoutError" ? new Error(ALREADY_OPEN) : err);
+      });
+  });
+}
+
+/**
+ * Open the database, once, for everyone.
+ *
+ * Lock first, then load the model layer, then open — in that order, so a
+ * worker that will never own the database also never downloads and compiles
+ * the wasm for it.
+ */
+function bootOnce(): Promise<void> {
+  if (booted != null) return booted;
+
+  booted = (async () => {
+    await acquireDatabaseLock();
+    const loaded = await import("@yaakapp-internal/web");
+    await loaded.boot();
+    engine = loaded;
+  })();
+
+  booted.catch((err) => {
+    bootError = errorMessage(err);
+  });
+
+  return booted;
+}
+
+async function handle(port: MessagePort, message: ToWorker): Promise<void> {
+  if (message.type === "goodbye") {
+    ports.delete(port);
+    return;
+  }
+
+  // Every command waits for boot rather than the tab having to. Tabs post
+  // the moment they load; the port queues; this drains once the DB is open.
+  try {
+    await booted;
+  } catch {
+    send(port, { type: "error", id: message.id, message: bootError ?? "Database failed to open" });
+    return;
+  }
+  const { rpc, blob_get, blob_put, blob_delete } = engine!;
+
+  try {
+    switch (message.type) {
+      case "rpc": {
+        const outcome = rpc(message.cmd, message.payload, message.label) as {
+          result: unknown;
+          events: unknown[];
+        };
+        // Result first, to the caller; then the writes, to everyone including
+        // the caller. The store applies its own echo the same as any other
+        // window's, so it must arrive — and the caller's `await` resolving
+        // before its echo lands is fine, because it resolves on the same tick
+        // and the store reads on the next.
+        send(port, { type: "result", id: message.id, result: outcome.result });
+        if (outcome.events.length > 0) {
+          broadcast({ type: "event", event: "model_writes", payload: outcome.events });
+        }
+        return;
+      }
+      case "blob_get": {
+        const bytes = blob_get(message.blobId);
+        if (bytes == null) {
+          send(port, { type: "result", id: message.id, result: null });
+        } else {
+          // Copy into a fresh buffer we can transfer: the wasm's memory
+          // cannot leave the worker.
+          const out = new Uint8Array(bytes.byteLength);
+          out.set(bytes);
+          send(port, { type: "result", id: message.id, result: out.buffer }, [out.buffer]);
+        }
+        return;
+      }
+      case "blob_put": {
+        blob_put(message.blobId, new Uint8Array(message.bytes));
+        send(port, { type: "result", id: message.id, result: null });
+        return;
+      }
+      case "blob_delete": {
+        blob_delete(message.blobId);
+        send(port, { type: "result", id: message.id, result: null });
+        return;
+      }
+    }
+  } catch (err) {
+    send(port, { type: "error", id: message.id, message: errorMessage(err) });
+  }
+}
+
+function attach(port: MessagePort): void {
+  ports.add(port);
+  port.onmessage = (e: MessageEvent<ToWorker>) => void handle(port, e.data);
+  port.start?.();
+
+  // Proof of life, before boot: the tab is timing this.
+  send(port, { type: "hello" });
+
+  bootOnce().then(
+    () => send(port, { type: "ready" }),
+    (err) => send(port, { type: "boot_error", message: errorMessage(err) }),
+  );
+}
+
+// Each tab arrives as a connect event with its own port.
+(self as unknown as SharedWorkerGlobalScope).onconnect = (e: MessageEvent) => {
+  attach(e.ports[0]!);
+};
@@ -5,7 +5,7 @@ export default defineConfig({
    "*": "vp check --fix",
  },
  lint: {
-    ignorePatterns: ["npm/**", "crates/yaak-templates/pkg/**", "**/bindings/gen_*.ts"],
+    ignorePatterns: ["npm/**", "crates/yaak-templates/pkg/**", "crates/yaak-web/pkg/**", "**/bindings/gen_*.ts"],
    options: {
      typeAware: true,
    },