Update chat API routes and add morph chat endpoint

Author: Gerome-Elassaad

app/api/chat/morph-chat/route.ts

@@ -0,0 +1,110 @@
+import { handleAPIError, createRateLimitResponse } from '@/lib/api-errors'
+import { Duration } from '@/lib/duration'
+import { getModelClient, LLMModel, LLMModelConfig } from '@/lib/models'
+import { applyPatch } from '@/lib/morph'
+import ratelimit from '@/lib/ratelimit'
+import { FragmentSchema, morphEditSchema, MorphEditSchema } from '@/lib/schema'
+import { generateObject, LanguageModel, CoreMessage } from 'ai'
+
+export const maxDuration = 300
+
+const rateLimitMaxRequests = process.env.RATE_LIMIT_MAX_REQUESTS
+  ? parseInt(process.env.RATE_LIMIT_MAX_REQUESTS)
+  : 10
+const ratelimitWindow = process.env.RATE_LIMIT_WINDOW
+  ? (process.env.RATE_LIMIT_WINDOW as Duration)
+  : '1d'
+
+
+export async function POST(req: Request) {
+  const {
+    messages,
+    model,
+    config,
+    currentFragment,
+  }: {
+    messages: CoreMessage[]
+    model: LLMModel
+    config: LLMModelConfig
+    currentFragment: FragmentSchema
+  } = await req.json()
+
+  // Rate limiting (same as chat route)
+  const limit = !config.apiKey
+    ? await ratelimit(
+        req.headers.get('x-forwarded-for'),
+        rateLimitMaxRequests,
+        ratelimitWindow,
+      )
+    : false
+
+  if (limit) {
+    return createRateLimitResponse(limit)
+  }
+
+  const { model: modelNameString, apiKey: modelApiKey, ...modelParams } = config
+  const modelClient = getModelClient(model, config)
+
+  try {
+    const contextualSystemPrompt = `You are a code editor. Generate a JSON response with exactly these fields:
+
+{
+  "commentary": "Explain what changes you are making",
+  "instruction": "One line description of the change", 
+  "edit": "The code changes with // ... existing code ... for unchanged parts",
+  "file_path": "${currentFragment.file_path}"
+}
+
+Current file: ${currentFragment.file_path}
+Current code:
+\`\`\`
+${currentFragment.code}
+\`\`\`
+
+`
+
+    const result = await generateObject({
+      model: modelClient as LanguageModel,
+      system: contextualSystemPrompt,
+      messages,
+      schema: morphEditSchema,
+      maxRetries: 0,
+      ...modelParams,
+    })
+
+    const editInstructions = result.object
+
+    // Apply edits using Morph
+    const morphResult = await applyPatch({
+      targetFile: currentFragment.file_path,
+      instructions: editInstructions.instruction,
+      initialCode: currentFragment.code,
+      codeEdit: editInstructions.edit,
+    })
+
+    // Return updated fragment in standard format
+    const updatedFragment: FragmentSchema = {
+      ...currentFragment,
+      code: morphResult.code,
+      commentary: editInstructions.commentary,
+    }
+
+    // Create a streaming response that matches the AI SDK format
+    const encoder = new TextEncoder()
+    const stream = new ReadableStream({
+      start(controller) {
+        const json = JSON.stringify(updatedFragment)
+        controller.enqueue(encoder.encode(json))
+        controller.close()
+      },
+    })
+
+    return new Response(stream, {
+      headers: {
+        'Content-Type': 'text/plain; charset=utf-8',
+      },
+    })
+  } catch (error: any) {
+    return handleAPIError(error, { hasOwnApiKey: !!config.apiKey })
+  }
+}

app/api/chat/route.ts

@@ -1,18 +1,13 @@
+import { handleAPIError, createRateLimitResponse } from '@/lib/api-errors'
 import { Duration } from '@/lib/duration'
-import {
-  getModelClient,
-  LLMModel,
-  LLMModelConfig,
-} from '@/lib/models'
+import { getModelClient, LLMModel, LLMModelConfig } from '@/lib/models'
 import { toPrompt } from '@/lib/prompt'
 import ratelimit from '@/lib/ratelimit'
 import { fragmentSchema as schema } from '@/lib/schema'
 import { Templates } from '@/lib/templates'
 import { streamObject, LanguageModel, CoreMessage } from 'ai'
 
 export const maxDuration = 300
-export const runtime = 'nodejs'
-export const dynamic = 'force-dynamic'
 
 const rateLimitMaxRequests = process.env.RATE_LIMIT_MAX_REQUESTS
   ? parseInt(process.env.RATE_LIMIT_MAX_REQUESTS)
@@ -47,21 +42,14 @@ export async function POST(req: Request) {
     : false
 
   if (limit) {
-    return new Response('You have reached your request limit for the day.', {
-      status: 429,
-      headers: {
-        'X-RateLimit-Limit': limit.amount.toString(),
-        'X-RateLimit-Remaining': limit.remaining.toString(),
-        'X-RateLimit-Reset': limit.reset.toString(),
-      },
-    })
+    return createRateLimitResponse(limit)
   }
 
   console.log('userID', userID)
   console.log('teamID', teamID)
-  console.log('template', template)
+  // console.log('template', template)
   console.log('model', model)
-  console.log('config', config)
+  // console.log('config', config)
 
   const { model: modelNameString, apiKey: modelApiKey, ...modelParams } = config
   const modelClient = getModelClient(model, config)
@@ -72,53 +60,12 @@ export async function POST(req: Request) {
       schema,
       system: toPrompt(template),
       messages,
-      maxRetries: 2,
+      maxRetries: 0, // do not retry on errors
       ...modelParams,
     })
 
     return stream.toTextStreamResponse()
   } catch (error: any) {
-    const isRateLimitError =
-      error && (error.statusCode === 429 || error.message.includes('limit'))
-    const isOverloadedError =
-      error && (error.statusCode === 529 || error.statusCode === 503)
-    const isAccessDeniedError =
-      error && (error.statusCode === 403 || error.statusCode === 401)
-
-    if (isRateLimitError) {
-      return new Response(
-        'The provider is currently unavailable due to request limit. Try using your own API key.',
-        {
-          status: 429,
-        },
-      )
-    }
-
-    if (isOverloadedError) {
-      return new Response(
-        'The provider is currently unavailable. Please try again later.',
-        {
-          status: 529,
-        },
-      )
-    }
-
-    if (isAccessDeniedError) {
-      return new Response(
-        'Access denied. Please make sure your API key is valid.',
-        {
-          status: 403,
-        },
-      )
-    }
-
-    console.error('Error:', error)
-
-    return new Response(
-      'An unexpected error has occurred. Please try again later.',
-      {
-        status: 500,
-      },
-    )
+    return handleAPIError(error, { hasOwnApiKey: !!config.apiKey })
   }
-}
+}