feat(mcp): add native result previews and interactive apps

waleedlatif1 · Oct 8, 2026 · Oct 8, 2026 · Oct 8, 2026 · Oct 8, 2026 · Oct 8, 2026
commit 385e46462fcaffc0cb57a0c5ba919269072cde65
diff --git a/.github/workflows/checks.yml b/.github/workflows/checks.yml
@@ -214,6 +214,34 @@ jobs:
           if-no-files-found: ignore
           retention-days: 7
 
+  mcp-app:
+    name: mcp-app
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - *checkout-mirror
+      - *checkout-plain
+      - name: Setup workspace
+        uses: ./.github/actions/setup
+        with:
+          provider: ${{ vars.CI_PROVIDER }}
+      - name: Install Chromium
+        working-directory: apps/sim
+        run: bunx playwright install --with-deps chromium
+      - name: Exercise MCP App sandbox
+        working-directory: apps/sim
+        env:
+          MCP_APP_E2E_REPORT_PATH: ${{ runner.temp }}/mcp-app.json
+        run: bun run test:mcp-app:e2e
+      - name: Upload MCP App report
+        if: failure()
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: mcp-app-report
+          path: ${{ runner.temp }}/mcp-app.json*
+          if-no-files-found: warn
+          retention-days: 7
+
   # Pull requests skip the live desktop suite only when every change is clearly unrelated to the
   # app it drives (docs, other apps, published content). Anything else, and any failure to work
   # out the diff, runs it: a pull request that skipped it wrongly would first fail on staging.
@@ -719,7 +747,7 @@ jobs:
   # on a cancelled run would report a cancelled head commit as passing.
   ci:
     name: ci
-    needs: [integration, e2e, desktop-changes, desktop-live, lint, test, build]
+    needs: [integration, e2e, mcp-app, desktop-changes, desktop-live, lint, test, build]
     if: ${{ always() }}
     runs-on: *runner-2vcpu
     timeout-minutes: 5

diff --git a/apps/sim/app/api/files/authorization.ts b/apps/sim/app/api/files/authorization.ts
@@ -122,7 +122,12 @@ export async function verifyFileAccess(
   options?: { requireWrite?: boolean; knowledgeAccess?: KnowledgeFileAccess }
 ): Promise<boolean> {
   /** Organization images require the Principal-aware Assistant application resolver. */
-  if (cloudKey.startsWith('assistant/') || cloudKey.startsWith('chat-images/')) return false
+  if (
+    cloudKey.startsWith('assistant/') ||
+    cloudKey.startsWith('chat-images/') ||
+    cloudKey.startsWith('chat-mcp/')
+  )
+    return false
   const requireWrite = options?.requireWrite ?? false
   try {
     const keyContext = inferContextFromKey(cloudKey)

diff --git a/apps/sim/app/api/files/serve/[...path]/route.ts b/apps/sim/app/api/files/serve/[...path]/route.ts
@@ -278,7 +278,8 @@ export const GET = withRouteHandler(
       const cloudKey = isCloudPath ? path.slice(1).join('/') : fullPath
 
       /** Chat images are served only through the current private-chat owner boundary. */
-      if (cloudKey.startsWith('chat-images/')) throw new FileNotFoundError('File not found')
+      if (cloudKey.startsWith('chat-images/') || cloudKey.startsWith('chat-mcp/'))
+        throw new FileNotFoundError('File not found')
 
       if (cloudKey.startsWith('assistant/')) {
         const principal = await internalSessionAuth.authenticate()

diff --git a/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/assets/[index]/route.ts b/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/assets/[index]/route.ts
@@ -0,0 +1,33 @@
+import { getMcpPresentationAssetContract } from '@/lib/api/contracts/mcp-presentations'
+import {
+  defineInternalBinaryRoute,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import { internalOrchestrationErrorPolicy } from '@/lib/api/server/routes/internal-json-route'
+import { readMcpResultAsset } from '@/lib/mothership/chat/application/mcp-results'
+
+export const dynamic = 'force-dynamic'
+export const GET = defineInternalBinaryRoute({
+  contract: getMcpPresentationAssetContract,
+  auth: internalSessionAuth,
+  operation: readMcpResultAsset.operation,
+  rateLimit: internalRateLimits.none({
+    reason:
+      'Bounded private MCP result delivery requires current chat ownership and connection authorization for live resources.',
+  }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params }) => params,
+  useCase: readMcpResultAsset,
+  present: ({ buffer, contentType, disposition }) => ({
+    body: new Uint8Array(buffer),
+    contentType,
+    contentLength: buffer.length,
+    contentDisposition: disposition,
+    headers: {
+      'Cache-Control': 'private, no-store',
+      'X-Content-Type-Options': 'nosniff',
+      'Content-Security-Policy': "sandbox; default-src 'none'",
+    },
+  }),
+})
diff --git a/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/frame/route.ts b/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/frame/route.ts
@@ -0,0 +1,33 @@
+import { getMcpAppFrameContract } from '@/lib/api/contracts/mcp-presentations'
+import {
+  defineInternalBinaryRoute,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import { internalOrchestrationErrorPolicy } from '@/lib/api/server/routes/internal-json-route'
+import { readMcpAppFrame } from '@/lib/mothership/chat/application/mcp-results'
+
+export const dynamic = 'force-dynamic'
+export const GET = defineInternalBinaryRoute({
+  contract: getMcpAppFrameContract,
+  auth: internalSessionAuth,
+  operation: readMcpAppFrame.operation,
+  rateLimit: internalRateLimits.none({
+    reason:
+      'Bounded private MCP result delivery requires current chat ownership and connection authorization for live resources.',
+  }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params }) => params,
+  useCase: readMcpAppFrame,
+  present: ({ buffer, contentType, policy }) => ({
+    body: new Uint8Array(buffer),
+    contentType,
+    contentLength: buffer.length,
+    headers: {
+      'Content-Security-Policy': policy,
+      'Cache-Control': 'private, no-store',
+      'Referrer-Policy': 'no-referrer',
+      'X-Content-Type-Options': 'nosniff',
+    },
+  }),
+})
diff --git a/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/resources/route.ts b/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/resources/route.ts
@@ -0,0 +1,21 @@
+import { readMcpAppResourceContract } from '@/lib/api/contracts/mcp-presentations'
+import {
+  defineInternalJsonRoute,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import { internalOrchestrationErrorPolicy } from '@/lib/api/server/routes/internal-json-route'
+import { readMcpAppResource } from '@/lib/mothership/chat/application/mcp-results'
+
+export const dynamic = 'force-dynamic'
+export const POST = defineInternalJsonRoute({
+  contract: readMcpAppResourceContract,
+  auth: internalSessionAuth,
+  operation: readMcpAppResource.operation,
+  rateLimit: internalRateLimits.user({ bucketName: 'mcp-apps' }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params, body }, { request }) => ({ ...params, ...body, signal: request.signal }),
+  parseOptions: { maxBodyBytes: 256 * 1024 },
+  useCase: readMcpAppResource,
+  staticResponseHeaders: { 'Cache-Control': 'private, no-store' },
+})
diff --git a/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/route.ts b/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/route.ts
@@ -0,0 +1,20 @@
+import { getMcpPresentationContract } from '@/lib/api/contracts/mcp-presentations'
+import {
+  defineInternalJsonRoute,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import { internalOrchestrationErrorPolicy } from '@/lib/api/server/routes/internal-json-route'
+import { readMcpResult } from '@/lib/mothership/chat/application/mcp-results'
+
+export const dynamic = 'force-dynamic'
+export const GET = defineInternalJsonRoute({
+  contract: getMcpPresentationContract,
+  auth: internalSessionAuth,
+  operation: readMcpResult.operation,
+  rateLimit: internalRateLimits.user({ bucketName: 'mcp-apps' }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params }) => params,
+  useCase: readMcpResult,
+  staticResponseHeaders: { 'Cache-Control': 'private, no-store' },
+})
diff --git a/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/tools/route.ts b/apps/sim/app/api/mothership/chats/[chatId]/mcp-results/[id]/tools/route.ts
@@ -0,0 +1,21 @@
+import { callMcpAppToolContract } from '@/lib/api/contracts/mcp-presentations'
+import {
+  defineInternalJsonRoute,
+  internalRateLimits,
+  internalSessionAuth,
+} from '@/lib/api/server/routes'
+import { internalOrchestrationErrorPolicy } from '@/lib/api/server/routes/internal-json-route'
+import { callMcpAppTool } from '@/lib/mothership/chat/application/mcp-results'
+
+export const dynamic = 'force-dynamic'
+export const POST = defineInternalJsonRoute({
+  contract: callMcpAppToolContract,
+  auth: internalSessionAuth,
+  operation: callMcpAppTool.operation,
+  rateLimit: internalRateLimits.user({ bucketName: 'mcp-apps' }),
+  errorPolicy: internalOrchestrationErrorPolicy,
+  mapInput: ({ params, body }, { request }) => ({ ...params, ...body, signal: request.signal }),
+  parseOptions: { maxBodyBytes: 256 * 1024 },
+  useCase: callMcpAppTool,
+  staticResponseHeaders: { 'Cache-Control': 'private, no-store' },
+})
diff --git a/apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/use-doc-preview-binary.ts b/apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/use-doc-preview-binary.ts
@@ -3,6 +3,7 @@
 import { useRef } from 'react'
 import type { WorkspaceFileRecord } from '@/lib/uploads/contexts/workspace'
 import { useWorkspaceFileBinary } from '@/hooks/queries/workspace-files'
+import { useFileContentSource } from '@/hooks/use-file-content-source'
 
 export type DocPreviewState = 'empty' | 'loading' | 'ready' | 'stale'
 
@@ -127,8 +128,10 @@ export function stepDocPreviewBinary({
  * binary resolves for the new file, so one viewer never renders another file's content.
  */
 export function useDocPreviewBinary(workspaceId: string, file: DocPreviewFile): DocPreviewBinary {
+  const source = useFileContentSource()
+  const hasCommittedContent = source.hasCommittedContent ?? (file.size ?? 0) > 0
   const query = useWorkspaceFileBinary(workspaceId, file.id, file.key, {
-    enabled: (file.size ?? 0) > 0,
+    enabled: hasCommittedContent,
     version: Number(new Date(file.updatedAt)) || file.size,
   })
 
@@ -145,7 +148,7 @@ export function useDocPreviewBinary(workspaceId: string, file: DocPreviewFile):
     data: query.data,
     isPlaceholderData: query.isPlaceholderData,
     error: (query.error as Error | null) ?? null,
-    hasCommittedContent: (file.size ?? 0) > 0,
+    hasCommittedContent,
     prevHasResolvedForFile: hasResolvedForFileRef.current,
     prevLastGood: lastGoodRef.current,
   })

diff --git a/apps/sim/app/workspace/[workspaceId]/home/components/chat-resource-panel.tsx b/apps/sim/app/workspace/[workspaceId]/home/components/chat-resource-panel.tsx
@@ -70,22 +70,22 @@ export function ChatResourcePanel({
     [onSummarize, chat.sendMessage]
   )
   return (
-    <ChatPanelLayout
-      collapsed={isResourceCollapsed}
-      label='resource view'
-      activityCount={resourceActivityIds.size}
-      onToggle={isResourceCollapsed ? expandResource : collapseResource}
-      onResize={handleResourceResizePointerDown}
-      onResizeKeyDown={handleResourceResizeKeyDown}
-      onResizeFocus={handleResourceResizeFocus}
-      panel={
-        <MothershipResourcesProvider
-          selectResource={selectResourceFromUser}
-          addResource={addResourceFromUser}
-          removeResource={removeResource}
-          reorderResources={reorderResources}
-          collapseResource={collapseResource}
-        >
+    <MothershipResourcesProvider
+      selectResource={selectResourceFromUser}
+      addResource={addResourceFromUser}
+      removeResource={removeResource}
+      reorderResources={reorderResources}
+      collapseResource={collapseResource}
+    >
+      <ChatPanelLayout
+        collapsed={isResourceCollapsed}
+        label='resource view'
+        activityCount={resourceActivityIds.size}
+        onToggle={isResourceCollapsed ? expandResource : collapseResource}
+        onResize={handleResourceResizePointerDown}
+        onResizeKeyDown={handleResourceResizeKeyDown}
+        onResizeFocus={handleResourceResizeFocus}
+        panel={
           <Suspense fallback={null}>
             <MothershipView
               ref={mothershipRef}
@@ -106,10 +106,10 @@ export function ChatResourcePanel({
               className={skipResourceTransition ? 'transition-none!' : undefined}
             />
           </Suspense>
-        </MothershipResourcesProvider>
-      }
-    >
-      {children}
-    </ChatPanelLayout>
+        }
+      >
+        {children}
+      </ChatPanelLayout>
+    </MothershipResourcesProvider>
   )
 }
diff --git a/...ace/[workspaceId]/home/components/message-content/components/agent-group/lane-activity.ts b/...ace/[workspaceId]/home/components/message-content/components/agent-group/lane-activity.ts
@@ -1,3 +1,4 @@
+import { compactMcpPresentation } from '@/lib/mcp/presentation'
 import { RETIRED_BROWSER_REQUEST_TAKEOVER_ID } from '@/lib/mothership/tools/retired-tools'
 import {
   collectGroupTools,
@@ -17,6 +18,7 @@ function isStandaloneItem(item: AgentGroupItem): boolean {
   return (
     item.type !== 'tool' ||
     needsToolInput(item.data) ||
+    !!compactMcpPresentation(item.data.result?.output) ||
     item.data.toolName === RETIRED_BROWSER_REQUEST_TAKEOVER_ID
   )
 }

diff --git a/...e/[workspaceId]/home/components/message-content/components/agent-group/tool-call-item.tsx b/...e/[workspaceId]/home/components/message-content/components/agent-group/tool-call-item.tsx
@@ -1,6 +1,7 @@
 import { type ReactNode, useMemo } from 'react'
 import { isPlainRecord } from '@sim/utils/object'
 import { ActivityStatus, type ActivityStatusProps } from '@/components/ui/activity-status'
+import { compactMcpPresentation } from '@/lib/mcp/presentation'
 import {
   CallIntegrationTool,
   Read as ReadTool,
@@ -11,6 +12,7 @@ import { RETIRED_BROWSER_REQUEST_TAKEOVER_ID } from '@/lib/mothership/tools/reti
 import { extractStreamingStringArgument } from '@/lib/mothership/tools/streaming-args'
 import { useToolCallTitle } from '@/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/tool-call-title'
 import { ToolPermissionCard } from '@/app/workspace/[workspaceId]/home/components/message-content/components/agent-group/tool-permission-card'
+import { McpResult } from '@/app/workspace/[workspaceId]/home/components/message-content/components/mcp-result/mcp-result'
 import {
   BrowserTakeoverQuestion,
   CredentialDisplay,
@@ -181,5 +183,13 @@ export function ToolCallItem({
       <ToolIcon className='size-full' />
     ),
   }
+  const presentation = compactMcpPresentation(result?.output)
+  if (presentation && !renderStatus)
+    return (
+      <div>
+        <ActivityStatus {...activity} />
+        <McpResult receipt={presentation.mcpPresentation} />
+      </div>
+    )
   return renderStatus ? renderStatus(activity) : <ActivityStatus {...activity} />
 }