fix(devframe): enforce MCP state exposure policy

packages/devframe/src/adapters/mcp/__tests__/mcp-server.test.ts

@@ -12,13 +12,13 @@ function nullHost(): DevframeHost {
   }
 }
 
-async function bootPair() {
+async function bootPair(exposeSharedState: boolean | ((key: string) => boolean) = true) {
   const ctx = await createHostContext({ cwd: process.cwd(), mode: 'dev', host: nullHost() })
 
   const server = buildMcpServerFromContext(ctx, {
     serverName: 'test',
     serverVersion: '0.0.0-test',
-    exposeSharedState: true,
+    exposeSharedState,
   })
 
   const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair()
@@ -312,49 +312,98 @@ describe('mcp adapter (in-memory)', () => {
   })
 
   it('hides devframe:state:read when shared-state exposure is disabled', async () => {
-    const ctx = await createHostContext({ cwd: process.cwd(), mode: 'dev', host: nullHost() })
-    const server = buildMcpServerFromContext(ctx, {
-      serverName: 'test',
-      serverVersion: '0.0.0-test',
-      exposeSharedState: false,
-    })
-    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair()
-    await server.connect(serverTransport)
-    const client = new Client({ name: 'test-client', version: '0.0.0' })
-    await client.connect(clientTransport)
+    const { client, cleanup } = await bootPair(false)
     try {
       const listed = await client.listTools()
       expect(listed.tools.map(t => t.name)).not.toContain('devframe_state_read')
     }
     finally {
-      await client.close()
-      await server.close()
+      await cleanup()
     }
   })
 
   it('respects the shared-state filter in devframe:state:read', async () => {
-    const ctx = await createHostContext({ cwd: process.cwd(), mode: 'dev', host: nullHost() })
-    await ctx.rpc.sharedState.get('visible:key', { initialValue: { n: 1 } })
-    await ctx.rpc.sharedState.get('hidden:key', { initialValue: { n: 2 } })
-    const server = buildMcpServerFromContext(ctx, {
-      serverName: 'test',
-      serverVersion: '0.0.0-test',
-      exposeSharedState: key => key.startsWith('visible:'),
-    })
-    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair()
-    await server.connect(serverTransport)
-    const client = new Client({ name: 'test-client', version: '0.0.0' })
-    await client.connect(clientTransport)
+    const { ctx, client, cleanup } = await bootPair(key => key.startsWith('visible:'))
     try {
+      await ctx.rpc.sharedState.get('visible:key', { initialValue: { n: 1 } })
+      await ctx.rpc.sharedState.get('hidden:key', { initialValue: { n: 2 } })
+
       const keys = await client.callTool({ name: 'devframe_state_read', arguments: {} })
       expect(keys.structuredContent).toEqual({ keys: ['visible:key'] })
 
       const hidden = await client.callTool({ name: 'devframe_state_read', arguments: { key: 'hidden:key' } })
       expect(hidden.isError).toBe(true)
     }
     finally {
-      await client.close()
-      await server.close()
+      await cleanup()
+    }
+  })
+
+  it('omits state resources and rejects a direct URI read when exposure is disabled', async () => {
+    const { ctx, client, cleanup } = await bootPair(false)
+    try {
+      await ctx.rpc.sharedState.get('alpha:key', { initialValue: { n: 1 } })
+
+      const listed = await client.listResources()
+      expect(listed.resources.some(r => r.uri.startsWith('devframe://state/'))).toBe(false)
+
+      // A caller that knows the key must not bypass the policy by reading the
+      // URI directly.
+      await expect(
+        client.readResource({ uri: `devframe://state/${encodeURIComponent('alpha:key')}` }),
+      ).rejects.toThrow()
+    }
+    finally {
+      await cleanup()
+    }
+  })
+
+  it('applies the filter to direct URI reads, not only discovery', async () => {
+    const { ctx, client, cleanup } = await bootPair(key => key.startsWith('visible:'))
+    try {
+      await ctx.rpc.sharedState.get('visible:key', { initialValue: { n: 1 } })
+      await ctx.rpc.sharedState.get('hidden:key', { initialValue: { n: 2 } })
+
+      const listed = await client.listResources()
+      const stateUris = listed.resources.filter(r => r.uri.startsWith('devframe://state/')).map(r => r.uri)
+      expect(stateUris).toEqual([`devframe://state/${encodeURIComponent('visible:key')}`])
+
+      const allowed = await client.readResource({ uri: `devframe://state/${encodeURIComponent('visible:key')}` })
+      const c = allowed.contents[0] as { text: string }
+      expect(JSON.parse(c.text)).toEqual({ n: 1 })
+
+      // Known key, denied by predicate: rejected before storage access.
+      await expect(
+        client.readResource({ uri: `devframe://state/${encodeURIComponent('hidden:key')}` }),
+      ).rejects.toThrow()
+    }
+    finally {
+      await cleanup()
+    }
+  })
+
+  it('agrees between the state-read tool and the resource path for the same policy', async () => {
+    const { ctx, client, cleanup } = await bootPair(key => key.startsWith('visible:'))
+    try {
+      await ctx.rpc.sharedState.get('visible:key', { initialValue: { n: 1 } })
+      await ctx.rpc.sharedState.get('hidden:key', { initialValue: { n: 2 } })
+
+      // Allowed key: both paths return the same value.
+      const toolValue = await client.callTool({ name: 'devframe_state_read', arguments: { key: 'visible:key' } })
+      expect(toolValue.structuredContent).toEqual({ key: 'visible:key', value: { n: 1 } })
+      const resourceValue = await client.readResource({ uri: `devframe://state/${encodeURIComponent('visible:key')}` })
+      const c = resourceValue.contents[0] as { text: string }
+      expect(JSON.parse(c.text)).toEqual({ n: 1 })
+
+      // Denied key: both paths reject.
+      const toolHidden = await client.callTool({ name: 'devframe_state_read', arguments: { key: 'hidden:key' } })
+      expect(toolHidden.isError).toBe(true)
+      await expect(
+        client.readResource({ uri: `devframe://state/${encodeURIComponent('hidden:key')}` }),
+      ).rejects.toThrow()
+    }
+    finally {
+      await cleanup()
     }
   })
 })

packages/devframe/src/adapters/mcp/build-server.ts

@@ -332,6 +332,8 @@ function registerResourceHandlers(
   ctx: DevframeNodeContext,
   exposeSharedState: boolean | ((key: string) => boolean),
 ): void {
+  const stateFilter = sharedStateFilter(exposeSharedState)
+
   server.setRequestHandler('resources/list', async () => {
     const resources = ctx.agent.list().resources.map(resource => ({
       uri: resource.uri,
@@ -340,10 +342,9 @@ function registerResourceHandlers(
       mimeType: resource.mimeType,
     }))
 
-    if (exposeSharedState !== false) {
-      const filter = typeof exposeSharedState === 'function' ? exposeSharedState : () => true
+    if (stateFilter) {
       for (const key of ctx.rpc.sharedState.keys()) {
-        if (!filter(key))
+        if (!stateFilter(key))
           continue
         resources.push({
           uri: `devframe://state/${encodeURIComponent(key)}`,
@@ -375,6 +376,12 @@ function registerResourceHandlers(
     }
 
     if (parsed.kind === 'state') {
+      // Apply the exposure policy at the read, not only during discovery:
+      // a caller that knows a filtered key must not bypass it. Deny with the
+      // same DF0048 the built-in read tool uses, so a denied key is
+      // indistinguishable from a missing one.
+      if (!stateFilter || !stateFilter(parsed.key))
+        throw diagnostics.DF0048({ key: parsed.key })
       const state = await ctx.rpc.sharedState.get(parsed.key)
       return {
         contents: [

plans/README.md

@@ -8,7 +8,7 @@ Generated by the improve skill on 2026-09-01 at commit `2d978f84`. Execute in th
 |---|---|---|---|---|---|
 | 001 | Pin privileged GitHub Actions dependencies | P1 | S | - | TODO |
 | 002 | Require authentication on route-based MCP | P1 | M | 001 | TODO |
-| 003 | Enforce shared-state exposure policy on direct MCP reads | P1 | S | 002 | TODO |
+| 003 | Enforce shared-state exposure policy on direct MCP reads | P1 | S | 002 | DONE |
 | 004 | Contain remote asset materialization | P1 | S | - | DONE |
 | 005 | Block Data Inspector prototype-chain writes | P1 | S | - | DONE |
 | 006 | Validate request-derived authentication-link origins | P1 | M | - | DONE |