durable stream for files

Author: icecrasher321

apps/sim/app/api/copilot/chat/queries.ts

@@ -3,13 +3,17 @@ import { copilotChats } from '@sim/db/schema'
 import { createLogger } from '@sim/logger'
 import { and, desc, eq } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
+import { getLatestRunForStream } from '@/lib/copilot/async-runs/repository'
 import { getAccessibleCopilotChat } from '@/lib/copilot/chat/lifecycle'
 import {
   authenticateCopilotRequestSessionOnly,
   createBadRequestResponse,
   createInternalServerErrorResponse,
   createUnauthorizedResponse,
 } from '@/lib/copilot/request/http'
+import { readFilePreviewSessions } from '@/lib/copilot/request/session'
+import { readEvents } from '@/lib/copilot/request/session/buffer'
+import { toStreamBatchEvent } from '@/lib/copilot/request/session/types'
 import { authorizeWorkflowByWorkspacePermission } from '@/lib/workflows/utils'
 import { assertActiveWorkspaceAccess } from '@/lib/workspaces/permissions/utils'
 
@@ -63,8 +67,60 @@ export async function GET(req: NextRequest) {
         return NextResponse.json({ success: false, error: 'Chat not found' }, { status: 404 })
       }
 
+      let streamSnapshot: {
+        events: ReturnType<typeof toStreamBatchEvent>[]
+        previewSessions: Awaited<ReturnType<typeof readFilePreviewSessions>>
+        status: string
+      } | null = null
+      if (chat.conversationId) {
+        try {
+          const [events, previewSessions, run] = await Promise.all([
+            readEvents(chat.conversationId, '0'),
+            readFilePreviewSessions(chat.conversationId).catch((error) => {
+              logger.warn('Failed to read preview sessions for copilot chat', {
+                chatId,
+                conversationId: chat.conversationId,
+                error: error instanceof Error ? error.message : String(error),
+              })
+              return []
+            }),
+            getLatestRunForStream(chat.conversationId, authenticatedUserId).catch((error) => {
+              logger.warn('Failed to fetch latest run for copilot chat snapshot', {
+                chatId,
+                conversationId: chat.conversationId,
+                error: error instanceof Error ? error.message : String(error),
+              })
+              return null
+            }),
+          ])
+
+          streamSnapshot = {
+            events: events.map(toStreamBatchEvent),
+            previewSessions,
+            status:
+              typeof run?.status === 'string'
+                ? run.status
+                : events.length > 0
+                  ? 'active'
+                  : 'unknown',
+          }
+        } catch (error) {
+          logger.warn('Failed to load copilot chat stream snapshot', {
+            chatId,
+            conversationId: chat.conversationId,
+            error: error instanceof Error ? error.message : String(error),
+          })
+        }
+      }
+
       logger.info(`Retrieved chat ${chatId}`)
-      return NextResponse.json({ success: true, chat: transformChat(chat) })
+      return NextResponse.json({
+        success: true,
+        chat: {
+          ...transformChat(chat),
+          ...(streamSnapshot ? { streamSnapshot } : {}),
+        },
+      })
     }
 
     if (!workflowId && !workspaceId) {

apps/sim/app/api/copilot/chat/stream/route.test.ts

@@ -12,11 +12,13 @@ import {
 const {
   getLatestRunForStream,
   readEvents,
+  readFilePreviewSessions,
   checkForReplayGap,
   authenticateCopilotRequestSessionOnly,
 } = vi.hoisted(() => ({
   getLatestRunForStream: vi.fn(),
   readEvents: vi.fn(),
+  readFilePreviewSessions: vi.fn(),
   checkForReplayGap: vi.fn(),
   authenticateCopilotRequestSessionOnly: vi.fn(),
 }))
@@ -27,6 +29,7 @@ vi.mock('@/lib/copilot/async-runs/repository', () => ({
 
 vi.mock('@/lib/copilot/request/session', () => ({
   readEvents,
+  readFilePreviewSessions,
   checkForReplayGap,
   createEvent: (event: Record<string, unknown>) => ({
     stream: {
@@ -74,9 +77,50 @@ describe('copilot chat stream replay route', () => {
       isAuthenticated: true,
     })
     readEvents.mockResolvedValue([])
+    readFilePreviewSessions.mockResolvedValue([])
     checkForReplayGap.mockResolvedValue(null)
   })
 
+  it('returns preview sessions in batch mode', async () => {
+    getLatestRunForStream.mockResolvedValue({
+      status: 'active',
+      executionId: 'exec-1',
+      id: 'run-1',
+    })
+    readFilePreviewSessions.mockResolvedValue([
+      {
+        schemaVersion: 1,
+        id: 'preview-1',
+        streamId: 'stream-1',
+        toolCallId: 'preview-1',
+        status: 'streaming',
+        fileName: 'draft.md',
+        previewText: 'hello',
+        previewVersion: 2,
+        updatedAt: '2026-04-10T00:00:00.000Z',
+      },
+    ])
+
+    const response = await GET(
+      new NextRequest(
+        'http://localhost:3000/api/copilot/chat/stream?streamId=stream-1&after=0&batch=true'
+      )
+    )
+
+    expect(response.status).toBe(200)
+    await expect(response.json()).resolves.toMatchObject({
+      success: true,
+      previewSessions: [
+        expect.objectContaining({
+          id: 'preview-1',
+          previewText: 'hello',
+          previewVersion: 2,
+        }),
+      ],
+      status: 'active',
+    })
+  })
+
   it('stops replay polling when run becomes cancelled', async () => {
     getLatestRunForStream
       .mockResolvedValueOnce({

apps/sim/app/api/copilot/chat/stream/route.ts

@@ -11,6 +11,7 @@ import {
   createEvent,
   encodeSSEEnvelope,
   readEvents,
+  readFilePreviewSessions,
   SSE_RESPONSE_HEADERS,
 } from '@/lib/copilot/request/session'
 import { toStreamBatchEvent } from '@/lib/copilot/request/session/types'
@@ -113,17 +114,28 @@ export async function GET(request: NextRequest) {
 
   if (batchMode) {
     const afterSeq = afterCursor || '0'
-    const events = await readEvents(streamId, afterSeq)
+    const [events, previewSessions] = await Promise.all([
+      readEvents(streamId, afterSeq),
+      readFilePreviewSessions(streamId).catch((error) => {
+        logger.warn('Failed to read preview sessions for stream batch', {
+          streamId,
+          error: error instanceof Error ? error.message : String(error),
+        })
+        return []
+      }),
+    ])
     const batchEvents = events.map(toStreamBatchEvent)
     logger.info('[Resume] Batch response', {
       streamId,
       afterCursor: afterSeq,
       eventCount: batchEvents.length,
+      previewSessionCount: previewSessions.length,
       runStatus: run.status,
     })
     return NextResponse.json({
       success: true,
       events: batchEvents,
+      previewSessions,
       status: run.status,
     })
   }

apps/sim/app/api/mothership/chats/[chatId]/route.ts

@@ -4,14 +4,17 @@ import { createLogger } from '@sim/logger'
 import { and, eq, sql } from 'drizzle-orm'
 import { type NextRequest, NextResponse } from 'next/server'
 import { z } from 'zod'
+import { getLatestRunForStream } from '@/lib/copilot/async-runs/repository'
 import { getAccessibleCopilotChat } from '@/lib/copilot/chat/lifecycle'
 import {
   authenticateCopilotRequestSessionOnly,
   createBadRequestResponse,
   createInternalServerErrorResponse,
   createUnauthorizedResponse,
 } from '@/lib/copilot/request/http'
+import type { FilePreviewSession } from '@/lib/copilot/request/session'
 import { readEvents } from '@/lib/copilot/request/session/buffer'
+import { readFilePreviewSessions } from '@/lib/copilot/request/session/file-preview-session'
 import { type StreamBatchEvent, toStreamBatchEvent } from '@/lib/copilot/request/session/types'
 import { taskPubSub } from '@/lib/copilot/tasks'
 import { captureServerEvent } from '@/lib/posthog/server'
@@ -49,16 +52,37 @@ export async function GET(
 
     let streamSnapshot: {
       events: StreamBatchEvent[]
+      previewSessions: FilePreviewSession[]
       status: string
     } | null = null
 
     if (chat.conversationId) {
       try {
-        const events = await readEvents(chat.conversationId, '0')
+        const [events, previewSessions] = await Promise.all([
+          readEvents(chat.conversationId, '0'),
+          readFilePreviewSessions(chat.conversationId).catch((error) => {
+            logger.warn('Failed to read preview sessions for mothership chat', {
+              chatId,
+              conversationId: chat.conversationId,
+              error: error instanceof Error ? error.message : String(error),
+            })
+            return []
+          }),
+        ])
+        const run = await getLatestRunForStream(chat.conversationId, userId).catch((error) => {
+          logger.warn('Failed to fetch latest run for mothership chat snapshot', {
+            chatId,
+            conversationId: chat.conversationId,
+            error: error instanceof Error ? error.message : String(error),
+          })
+          return null
+        })
 
         streamSnapshot = {
           events: events.map(toStreamBatchEvent),
-          status: events.length > 0 ? 'active' : 'unknown',
+          previewSessions,
+          status:
+            typeof run?.status === 'string' ? run.status : events.length > 0 ? 'active' : 'unknown',
         }
       } catch (error) {
         logger.warn('Failed to read stream snapshot for mothership chat', {

apps/sim/app/workspace/[workspaceId]/files/components/file-viewer/file-viewer.tsx

@@ -29,7 +29,6 @@ import {
   useWorkspaceFileContent,
 } from '@/hooks/queries/workspace-files'
 import { useAutosave } from '@/hooks/use-autosave'
-import { useStreamingText } from '@/hooks/use-streaming-text'
 import { DataTable } from './data-table'
 import { PreviewPanel, resolvePreviewType } from './preview-panel'
 
@@ -526,8 +525,7 @@ function TextEditor({
 
   const isStreaming = isStreamInteractionLocked
   const isEditorReadOnly = isStreamInteractionLocked || !canEdit
-  const revealedContent = useStreamingText(content, false)
-  const renderedContent = isStreaming ? revealedContent : content
+  const renderedContent = content
   const gutterWidthPx = useMemo(() => {
     const lineCount = renderedContent.split('\n').length
     return calculateGutterWidth(lineCount)
@@ -731,7 +729,7 @@ function TextEditor({
     const el = (shouldUseCodeRenderer ? codeScrollRef.current : textareaRef.current) ?? null
     if (!el) return
     el.scrollTop = el.scrollHeight
-  }, [isStreaming, revealedContent, shouldUseCodeRenderer])
+  }, [isStreaming, renderedContent, shouldUseCodeRenderer])
 
   if (streamingContent === undefined) {
     if (isLoading) return DOCUMENT_SKELETON