diff --git a/package-lock.json b/package-lock.json
index de4cca53..7dfa923f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,7 +9,7 @@
         "plugins/*"
       ],
       "dependencies": {
-        "@yaakapp/api": "^0.5.0"
+        "@yaakapp/api": "^0.5.1"
       },
       "devDependencies": {
         "@types/node": "^22.7.4",
@@ -999,9 +999,9 @@
       }
     },
     "node_modules/@yaakapp/api": {
-      "version": "0.5.0",
-      "resolved": "https://registry.npmjs.org/@yaakapp/api/-/api-0.5.0.tgz",
-      "integrity": "sha512-M0PPLGWQft+eQOOJ7ubwvRm3LTYXjAWQ8nniiqV3TkRcwa5++PteIH0OHV2L3Pei8cRQA8S25AD+RajyvFC8XQ==",
+      "version": "0.5.1",
+      "resolved": "https://registry.npmjs.org/@yaakapp/api/-/api-0.5.1.tgz",
+      "integrity": "sha512-0YFrrTJVjrnsSm9BTxSnz1pd1+Q52/CBV1QpTVtXPPqlSIwcvj7jMdwuDpSKy5G8xbaoVzTgBnW25RgKog/q7g==",
       "dependencies": {
         "@types/node": "^22.5.4"
       }
@@ -1054,10 +1054,6 @@
       "resolved": "plugins/importer-yaak",
       "link": true
     },
-    "node_modules/@yaakapp/template-function-file": {
-      "resolved": "plugins/template-function-file",
-      "link": true
-    },
     "node_modules/@yaakapp/template-function-fs": {
       "resolved": "plugins/template-function-fs",
       "link": true
@@ -7196,7 +7192,8 @@
     },
     "plugins/template-function-file": {
       "name": "@yaakapp/template-function-file",
-      "version": "0.0.1"
+      "version": "0.0.1",
+      "extraneous": true
     },
     "plugins/template-function-fs": {
       "name": "@yaakapp/template-function-fs",
@@ -7225,6 +7222,11 @@
       "devDependencies": {
         "@types/jsonpath": "^0.2.4"
       }
+    },
+    "plugins/template-function-secure": {
+      "name": "@yaakapp/template-function-secure",
+      "version": "0.0.1",
+      "extraneous": true
     }
   }
 }
diff --git a/package.json b/package.json
index ef57489a..1e60d96c 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,6 @@
     "workspaces-run": "^1.0.2"
   },
   "dependencies": {
-    "@yaakapp/api": "^0.5.0"
+    "@yaakapp/api": "^0.5.1"
   }
 }
diff --git a/plugins/importer-insomnia/src/index.ts b/plugins/importer-insomnia/src/index.ts
index d4e04b0a..e589365a 100644
--- a/plugins/importer-insomnia/src/index.ts
+++ b/plugins/importer-insomnia/src/index.ts
@@ -101,7 +101,7 @@ function importEnvironment(e: any, workspaceId: string): ExportResources['enviro
     createdAt: e.created ? new Date(e.created).toISOString().replace('Z', '') : undefined,
     updatedAt: e.updated ? new Date(e.updated).toISOString().replace('Z', '') : undefined,
     workspaceId: convertId(workspaceId),
-    environmentId: e.parentId === workspaceId ? null : convertId(e.parentId),
+    base: e.parentId === workspaceId,
     model: 'environment',
     name: e.name,
     variables: Object.entries(e.data).map(([name, value]) => ({
diff --git a/plugins/importer-insomnia/tests/fixtures/basic.output.json b/plugins/importer-insomnia/tests/fixtures/basic.output.json
index f989ec0e..c1381750 100644
--- a/plugins/importer-insomnia/tests/fixtures/basic.output.json
+++ b/plugins/importer-insomnia/tests/fixtures/basic.output.json
@@ -3,7 +3,7 @@
     "environments": [
       {
         "createdAt": "2025-01-13T15:15:43.767",
-        "environmentId": null,
+        "base": true,
         "id": "GENERATE_ID::env_16c0dec5b77c414ae0e419b8f10c3701300c5900",
         "model": "environment",
         "name": "Base Environment",
@@ -18,7 +18,7 @@
       },
       {
         "createdAt": "2025-01-13T15:15:58.515",
-        "environmentId": "GENERATE_ID::env_16c0dec5b77c414ae0e419b8f10c3701300c5900",
+        "base": false,
         "id": "GENERATE_ID::env_799ae3d723ef44af91b4817e5d057e6d",
         "model": "environment",
         "name": "Production",
@@ -33,7 +33,7 @@
       },
       {
         "createdAt": "2025-01-13T15:16:14.707",
-        "environmentId": "GENERATE_ID::env_16c0dec5b77c414ae0e419b8f10c3701300c5900",
+        "base": false,
         "id": "GENERATE_ID::env_030fbfdbb274426ebd78e2e6518f8553",
         "model": "environment",
         "name": "Staging",
diff --git a/plugins/importer-yaak/src/index.ts b/plugins/importer-yaak/src/index.ts
index d4295358..1a71cfbb 100644
--- a/plugins/importer-yaak/src/index.ts
+++ b/plugins/importer-yaak/src/index.ts
@@ -46,7 +46,7 @@ export function migrateImport(contents: string) {
       parsed.resources.environments = parsed.resources.environments ?? [];
       parsed.resources.environments.push(baseEnvironment);
 
-      // Delete variables key from workspace
+      // Delete variables key from the workspace
       delete workspace.variables;
 
       // Add environmentId to relevant environments
@@ -58,6 +58,14 @@ export function migrateImport(contents: string) {
     }
   }
 
+  // Migrate v3 to v4
+  for (const environment of parsed.resources.environments ?? []) {
+    if ('environmentId' in environment) {
+      environment.base = environment.environmentId == null;
+      delete environment.environmentId;
+    }
+  }
+
   return { resources: parsed.resources }; // Should already be in the correct format
 }
 
diff --git a/plugins/importer-yaak/tests/index.test.ts b/plugins/importer-yaak/tests/index.test.ts
index 533acd6e..a55e62b1 100644
--- a/plugins/importer-yaak/tests/index.test.ts
+++ b/plugins/importer-yaak/tests/index.test.ts
@@ -53,7 +53,7 @@ describe('importer-yaak', () => {
           }],
           environments: [{
             id: 'e_1',
-            environmentId: 'GENERATE_ID::base_env_w_1',
+            base: false,
             workspaceId: 'w_1',
             name: 'Production',
             variables: [{ name: 'E1', value: 'E1!' }],
diff --git a/plugins/template-function-file/package.json b/plugins/template-function-file/package.json
deleted file mode 100644
index 59aea7ab..00000000
--- a/plugins/template-function-file/package.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "name": "@yaakapp/template-function-file",
-  "private": true,
-  "version": "0.0.1",
-  "scripts": {
-    "build": "yaakcli build ./src/index.ts",
-    "dev": "yaakcli dev ./src/index.js"
-  }
-}
diff --git a/plugins/template-function-file/src/index.ts b/plugins/template-function-file/src/index.ts
deleted file mode 100644
index 472c1a0d..00000000
--- a/plugins/template-function-file/src/index.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import { CallTemplateFunctionArgs, Context, PluginDefinition } from '@yaakapp/api';
-import fs from 'node:fs';
-
-export const plugin: PluginDefinition = {
-  templateFunctions: [{
-    name: 'fs.readFile',
-    args: [{ title: 'Select File', type: 'file', name: 'path', label: 'File' }],
-    async onRender(_ctx: Context, args: CallTemplateFunctionArgs): Promise<string | null> {
-      if (!args.values.path) return null;
-
-      try {
-        return fs.promises.readFile(args.values.path, 'utf-8');
-      } catch (err) {
-        return null;
-      }
-    },
-  }],
-};