diff --git a/apps/buddy/extensions/sdk/authoring.ts b/apps/buddy/extensions/sdk/authoring.ts
index 731bcf779..b620b0cbb 100644
--- a/apps/buddy/extensions/sdk/authoring.ts
+++ b/apps/buddy/extensions/sdk/authoring.ts
@@ -4,7 +4,7 @@ export { validateExtensionFileCounts } from '../../platform/extensions/extension
 export { validateFileIconThemeFiles } from '../../platform/icons/fileIconThemeAssets'
 export { validateThemeFiles } from '../../platform/themes/themeAssets'
 export { createExtensionId, extensionAuthorSchema } from '../../shared/extensions/extensionIdentity'
-export { extensionManifestSchema, extensionPathSchema } from '../../shared/extensions/extensionManifest'
+export { extensionManifestSchema, extensionPackageManifest, extensionPathSchema } from '../../shared/extensions/extensionManifest'
 export { fileIconThemeDocumentSchema } from '../../shared/icons/fileIconTheme'
 
 export { themeDocumentSchema } from '../../shared/theme/themeDocument'
diff --git a/apps/buddy/extensions/sdk/plugin.mjs b/apps/buddy/extensions/sdk/plugin.mjs
index 742487ee4..b739697c9 100644
--- a/apps/buddy/extensions/sdk/plugin.mjs
+++ b/apps/buddy/extensions/sdk/plugin.mjs
@@ -3,7 +3,7 @@ import { createHash } from 'node:crypto'
 import fs from 'node:fs/promises'
 import path from 'node:path'
 import { zipSync } from 'fflate'
-import { compileExtensionSource, extensionIconUrl, extensionManifestSchema, extensionPathSchema, validateExtensionFileCounts, validateFileIconThemeFiles, validateThemeFiles } from './authoring.mjs'
+import { compileExtensionSource, extensionIconUrl, extensionManifestSchema, extensionPackageManifest, extensionPathSchema, validateExtensionFileCounts, validateFileIconThemeFiles, validateThemeFiles } from './authoring.mjs'
 
 export async function readPlugin(source) {
   const files = new Map()
@@ -46,6 +46,8 @@ export async function buildPlugin(source, destination, report = () => {}) {
   assert(source !== destination && !source.startsWith(`${destination}${path.sep}`), 'Output must not contain source')
   const { files, manifest } = await readPlugin(source)
   const result = manifest.format === 'source' ? await compileExtensionSource(files, manifest, report) : files
+  if (manifest.format !== 'source')
+    result.set('extension.json', new TextEncoder().encode(JSON.stringify(extensionPackageManifest(manifest))))
   const old = await fs.readdir(destination).catch(error => error.code === 'ENOENT' ? [] : Promise.reject(error))
   if (old.length)
     assert(JSON.parse(await fs.readFile(path.join(destination, 'extension.json'), 'utf8')).id === manifest.id, 'Output belongs to another plugin')
@@ -61,8 +63,10 @@ export async function packPlugin(source, destination, { license } = {}) {
   const { files, manifest, iconUrl } = await readPlugin(source)
   if (license && !files.has('LICENSE'))
     files.set('LICENSE', license)
+  const packageManifest = extensionPackageManifest(manifest)
+  files.set('extension.json', new TextEncoder().encode(JSON.stringify(packageManifest)))
   const bytes = zipSync(Object.fromEntries(files), { level: 6, mtime: new Date('2020-01-01T00:00:00Z') })
   await fs.mkdir(path.dirname(path.resolve(destination)), { recursive: true })
   await fs.writeFile(destination, bytes)
-  return { manifest, iconUrl, sha256: createHash('sha256').update(bytes).digest('hex'), size: bytes.length }
+  return { manifest: packageManifest, iconUrl, sha256: createHash('sha256').update(bytes).digest('hex'), size: bytes.length }
 }
diff --git a/apps/buddy/extensions/tools.mjs b/apps/buddy/extensions/tools.mjs
index b8b1ad934..adc3463c1 100644
--- a/apps/buddy/extensions/tools.mjs
+++ b/apps/buddy/extensions/tools.mjs
@@ -12,7 +12,7 @@ import { compileExtensionSource } from '../platform/extensions/compileExtensionS
 import { validateExtensionFileCounts } from '../platform/extensions/extensionLimits.ts'
 import { fileIconAssetPaths, readFileIconTheme, validateFileIconThemeFiles } from '../platform/icons/fileIconThemeAssets.ts'
 import { validateThemeFiles } from '../platform/themes/themeAssets.ts'
-import { extensionCompatible, extensionManifestSchema, extensionPathSchema } from '../shared/extensions/extensionManifest.ts'
+import { extensionCompatible, extensionManifestSchema, extensionPackageManifest, extensionPathSchema } from '../shared/extensions/extensionManifest.ts'
 import { themeAssetPaths, themeDocumentSchema } from '../shared/theme/themeDocument.ts'
 
 async function run() {
@@ -78,6 +78,7 @@ async function run() {
       }
     }
     await walk(source)
+    files['extension.json'] = new TextEncoder().encode(JSON.stringify(extensionPackageManifest(manifest)))
     const bytes = zipSync(files, { level: 6 })
     await fs.mkdir(path.dirname(path.resolve(output)), { recursive: true })
     await fs.writeFile(output, bytes)
@@ -122,7 +123,7 @@ async function run() {
         await fs.rm(destination, { recursive: true, force: true })
       await fs.mkdir(destination, { recursive: true })
       const compiledManifest = { ...manifest, entry: manifest.entry?.replace(/\.[^.]+$/, '.js'), contributes: { ...manifest.contributes, views: manifest.contributes.views.map(view => ({ ...view, entry: view.entry.replace(/\.[^.]+$/, '.js') })) } }
-      await fs.writeFile(path.join(destination, 'extension.json'), JSON.stringify(compiledManifest, null, 2))
+      await fs.writeFile(path.join(destination, 'extension.json'), JSON.stringify(extensionPackageManifest(compiledManifest), null, 2))
     }
     for (const [name, bytes] of themeFiles) {
       await fs.mkdir(path.dirname(path.join(destination, name)), { recursive: true })
diff --git a/apps/buddy/platform/extensions/__tests__/ExtensionPackageStore.spec.ts b/apps/buddy/platform/extensions/__tests__/ExtensionPackageStore.spec.ts
index 1940c1f42..effc6a7c1 100644
--- a/apps/buddy/platform/extensions/__tests__/ExtensionPackageStore.spec.ts
+++ b/apps/buddy/platform/extensions/__tests__/ExtensionPackageStore.spec.ts
@@ -21,6 +21,32 @@ afterEach(async () => {
 })
 
 describe('extension package contract', () => {
+  it('installs and reloads known contributions while ignoring unsupported declarations without granting them', async () => {
+    const { root, store } = await fixture()
+    const value = manifest()
+    const input = { ...value, futureMetadata: { enabled: true }, permissions: { ...value.permissions, inference: true, inferenceGpu: false, inferenceNetwork: ['https://example.com'], futureAccess: 'read', futureMetadata: { enabled: true } }, contributes: { ...value.contributes, futureProvider: { entry: 'future.js' } } }
+    const review = await reviewPackage(root, store, input)
+    expect(review.manifest.permissions).toEqual(value.permissions)
+    expect(review.manifest).toEqual(value)
+    expect(review.addedPermissions).toEqual(['selectedResource:read'])
+    await store.install(review.token)
+    const pkg = store.installed[value.id]!.current
+    expect(JSON.parse(await readFile(join(store.packageRoot(pkg), 'extension.json'), 'utf8')).permissions).toEqual(input.permissions)
+    const reloaded = new ExtensionPackageStore(store.root, '0.7.3')
+    await reloaded.load()
+    expect(reloaded.installed[value.id]!.current.manifest.permissions).toEqual(value.permissions)
+    expect(new TextDecoder().decode(await reloaded.asset(reloaded.installed[value.id]!.current, 'extension.js'))).toBe('export function activate() {}')
+  })
+  it.each([true, false, 'read', 'none', ['https://example.com'], [], 0, null, '', {}, [false]])('ignores unknown permissions regardless of their value: %j', (permission) => {
+    const value = manifest()
+    expect(extensionManifestSchema.parse({ ...value, permissions: { ...value.permissions, futureAccess: permission } })).toEqual(value)
+  })
+  it('still rejects malformed known permissions and contributions', () => {
+    const value = manifest()
+    expect(extensionManifestSchema.safeParse({ ...value, permissions: { ...value.permissions, network: false } }).success).toBe(false)
+    expect(extensionManifestSchema.safeParse({ ...value, permissions: { ...value.permissions, agent: [] } }).success).toBe(false)
+    expect(extensionManifestSchema.safeParse({ ...value, contributes: { ...value.contributes, commands: false } }).success).toBe(false)
+  })
   it('bounds state by UTF-8 bytes and requires permission for declared file views', () => {
     expect(extensionJsonSchema.safeParse('文'.repeat(90000)).success).toBe(false)
     expect(extensionManifestSchema.safeParse({ ...manifest(), permissions: { selectedResource: 'none', network: [] } }).success).toBe(false)
diff --git a/apps/buddy/platform/extensions/__tests__/ExtensionService.spec.ts b/apps/buddy/platform/extensions/__tests__/ExtensionService.spec.ts
index 3deab84ee..21179bc8d 100644
--- a/apps/buddy/platform/extensions/__tests__/ExtensionService.spec.ts
+++ b/apps/buddy/platform/extensions/__tests__/ExtensionService.spec.ts
@@ -54,6 +54,16 @@ async function fixture(overrides: Partial<ExtensionServicePorts> = {}, initialMa
 }
 const target = { spaceId: 'space', directoryId: 'directory', revision: 4, path: 'README.md' }
 
+it('ignores unsupported declarations without exposing new methods or expanding existing permissions', async () => {
+  const value = manifest()
+  const input = { ...value, permissions: { ...value.permissions, futureExecution: true, futureNetwork: ['https://example.com'] }, contributes: { ...value.contributes, futureExecution: { entry: 'future.js' } } }
+  const { service, hosts } = await fixture({}, input)
+  await service.execute(value.id, `${value.id}.open`, null)
+  await expect(hosts[0]!.broker('shell.execute', {})).rejects.toThrow('EXTENSION_METHOD_DENIED')
+  await expect(hosts[0]!.broker('network.get', { url: 'https://example.com' })).rejects.toThrow('EXTENSION_NETWORK_DENIED')
+  await expect(hosts[0]!.broker('notifications.show', { title: 'Unknown permission' })).rejects.toThrow('EXTENSION_NOTIFICATIONS_DENIED')
+})
+
 it.each([false, true])('uninstalls with clearData=%s while preserving other plugins and external files', async (clearData) => {
   const { root, store, service, hosts } = await fixture()
   const id = 'tests.reader'
diff --git a/apps/buddy/platform/extensions/__tests__/ExtensionSource.spec.ts b/apps/buddy/platform/extensions/__tests__/ExtensionSource.spec.ts
index b4d0feb61..de7a86afd 100644
--- a/apps/buddy/platform/extensions/__tests__/ExtensionSource.spec.ts
+++ b/apps/buddy/platform/extensions/__tests__/ExtensionSource.spec.ts
@@ -14,6 +14,14 @@ it('compiles package-local modules without executing source or build scripts', a
   expect(JSON.parse(decode(output.get('extension.json')))).toMatchObject({ id: manifest.id, format: 'compiled', entry: 'extension.js' })
 })
 
+it('emits only requested permissions while retaining runtime defaults and active grants after parsing', async () => {
+  const source = extensionManifestSchema.parse({ ...manifest, permissions: { selectedResource: 'read', notifications: true, network: ['https://example.com'], futureAccess: true, futureNetwork: ['https://unsupported.example.com'] } })
+  const output = await compileExtensionSource(encode({ 'extension.ts': 'export function activate() {}' }), source, () => {})
+  const packaged = JSON.parse(decode(output.get('extension.json')))
+  expect(packaged.permissions).toEqual({ selectedResource: 'read', notifications: true, network: ['https://example.com'] })
+  expect(extensionManifestSchema.parse(packaged)).toEqual({ ...source, format: 'compiled', entry: 'extension.js' })
+})
+
 it.each(['import "node:fs"', 'import "npm-library"', 'import "../../outside.js"', 'import(globalThis.path)'])('rejects imports outside the package: %s', async (text) => {
   await expect(compileExtensionSource(encode({ 'extension.ts': text }), manifest, () => {})).rejects.toThrow('EXTENSION_SOURCE_IMPORT_DENIED')
 })
diff --git a/apps/buddy/platform/extensions/compileExtensionSource.ts b/apps/buddy/platform/extensions/compileExtensionSource.ts
index 853f0d56e..9335127bf 100644
--- a/apps/buddy/platform/extensions/compileExtensionSource.ts
+++ b/apps/buddy/platform/extensions/compileExtensionSource.ts
@@ -1,7 +1,7 @@
 import type { ExtensionManifest } from '../../shared/extensions/extensionManifest'
 import { posix } from 'node:path'
 import ts from 'typescript'
-import { extensionPathSchema } from '../../shared/extensions/extensionManifest.ts'
+import { extensionPackageManifest, extensionPathSchema } from '../../shared/extensions/extensionManifest.ts'
 import { EXTENSION_UNO_STYLESHEET } from '../../shared/extensions/extensionStyles.ts'
 import { compileExtensionStyles } from './compileExtensionStyles.ts'
 
@@ -88,6 +88,6 @@ export async function compileExtensionSource(files: Map<string, Uint8Array>, man
     output.set(EXTENSION_UNO_STYLESHEET, styles)
   }
   const compiledManifest: ExtensionManifest = { ...manifest, format: 'compiled', ...(manifest.entry ? { entry: outputPath(manifest.entry) } : {}), contributes: { ...manifest.contributes, views: manifest.contributes.views.map(view => ({ ...view, entry: outputPath(view.entry) })) } }
-  output.set('extension.json', encode.encode(JSON.stringify(compiledManifest)))
+  output.set('extension.json', encode.encode(JSON.stringify(extensionPackageManifest(compiledManifest))))
   return output
 }
diff --git a/apps/buddy/service/resources/skills/plugin-creator/references/protocol.md b/apps/buddy/service/resources/skills/plugin-creator/references/protocol.md
index 512f5259a..cbd4e6644 100644
--- a/apps/buddy/service/resources/skills/plugin-creator/references/protocol.md
+++ b/apps/buddy/service/resources/skills/plugin-creator/references/protocol.md
@@ -75,7 +75,7 @@
 | `resourceExport: true` | 用户通过系统另存为窗口确认目标后，保存插件提供的字节 |
 | `network: ["https://example.com"]` | 通过宿主向列出的 HTTPS origin 发 GET 请求、下载文件或打开外链 |
 
-未声明权限默认为关闭。视图无法访问 Node、宿主 DOM、全局键盘、网络 fetch 或任意本地文件。资源和网络调用通过 API；用户在安装确认中查看权限。没有一般性消息订阅、系统剪贴板或屏幕截图接口。
+未声明权限默认为关闭，清单只需列出实际申请的权限，SDK 打包时会省略默认值。宿主忽略清单顶层、`permissions` 和 `contributes` 中不认识的声明，不因此提供对应能力；已知字段仍按类型和权限校验。需要新版能力时，通过 `engines.lexora` 和 API 版本声明兼容范围。视图无法访问 Node、宿主 DOM、全局键盘、网络 fetch 或任意本地文件。资源和网络调用通过 API；用户在安装确认中查看权限。没有一般性消息订阅、系统剪贴板或屏幕截图接口。
 
 ## 窗口效果
 
diff --git a/apps/buddy/shared/extensions/extensionManifest.ts b/apps/buddy/shared/extensions/extensionManifest.ts
index e1ec5844c..57618516c 100644
--- a/apps/buddy/shared/extensions/extensionManifest.ts
+++ b/apps/buddy/shared/extensions/extensionManifest.ts
@@ -76,7 +76,9 @@ export const extensionPermissionsSchema = z.object({
     const url = new URL(value)
     return url.protocol === 'https:' && url.origin === value && !url.username && !url.password
   }, 'Expected an HTTPS origin')).max(16).default([]),
-}).strict()
+})
+
+const extensionPermissionDefaults: Record<string, unknown> = extensionPermissionsSchema.parse({})
 export const extensionMetadataSchema = z.object({
   schemaVersion: z.number().int().positive(),
   id: extensionIdSchema,
@@ -116,8 +118,8 @@ export const extensionManifestSchema = extensionMetadataSchema.extend({
     views: z.array(z.object({ id: contributionId, title: z.string().min(1).max(100), entry: extensionPathSchema, stateVersion: z.number().int().min(1).max(10000).default(1), resource: z.enum(['selected-file', 'none']).default('selected-file'), location: z.enum(['context', 'page', 'window-overlay']).default('context'), when: workbenchConditionSchema.optional() }).strict()).max(16).default([]),
     placements: z.array(extensionPlacementSchema).max(16).default([]),
     navigation: z.object({ title: z.string().min(1).max(40), view: contributionId, when: workbenchConditionSchema.optional() }).strict().optional(),
-  }).strict(),
-}).strict().superRefine((manifest, context) => {
+  }),
+}).superRefine((manifest, context) => {
   const ids = new Set<string>()
   const settings = manifest.contributes.settings
   const agent = manifest.contributes.agent
@@ -229,6 +231,10 @@ export const extensionManifestSchema = extensionMetadataSchema.extend({
 export type ExtensionManifest = z.infer<typeof extensionManifestSchema>
 export type ExtensionPermissions = z.infer<typeof extensionPermissionsSchema>
 
+export function extensionPackageManifest(manifest: ExtensionManifest) {
+  return { ...manifest, permissions: Object.fromEntries(Object.entries(manifest.permissions).filter(([key, value]) => JSON.stringify(value) !== JSON.stringify(extensionPermissionDefaults[key]))) }
+}
+
 export function extensionCompatible(manifest: ExtensionManifest, version: string): boolean {
   return manifest.apiVersion <= EXTENSION_API_VERSION && satisfies(version, manifest.engines.lexora, { includePrerelease: true })
 }