feat: better backend error handling

Author: NamesMT

apps/backend-convex/convex/http/ai.ts

@@ -11,6 +11,7 @@ import { cors } from 'hono/cors'
 import { throttle } from 'kontroll'
 import { z } from 'zod'
 import { getAgentModel } from '../../utils/agent'
+import { getErrorMessage, normalizePossibleSDKError } from '../../utils/error'
 import { buildAiSdkMessage, buildSystemPrompt } from '../../utils/message'
 import { api, components, internal } from '../_generated/api'
 
@@ -191,10 +192,7 @@ aiApp
               model: getAgentModel({ provider, model, apiKey }),
               system: buildSystemPrompt({ provider, model }),
               messages: messagesContext,
-              onError: (ev) => {
-                console.error(ev.error)
-                throw ev.error
-              },
+              onError: (ev) => { throw ev.error },
             })
 
             for await (const textDelta of aiStream.textStream) {
@@ -217,16 +215,18 @@ aiApp
             controller.enqueue(encoder.encode(`o: ${JSON.stringify({ done: true })}\n`))
             controller.close()
           }
-          catch (error: any) {
+          catch (err: any) {
+            const error = normalizePossibleSDKError(err)
+            const errorMessage = getErrorMessage(error) ?? ''
             console.error(error)
 
-            aiResponse += `\n\nError encountered, stream stopped`
+            aiResponse += `\n\nError encountered, stream stopped: ${error?.name ? `[${error.name}]: ` : ''}${errorMessage}`
 
             doSave()
             await waitForSave()
             await c.env.runMutation(internal.messages.finishStreaming, { streamId })
 
-            controller.enqueue(encoder.encode(`o: ${JSON.stringify({ error: error.message })}\n`))
+            controller.enqueue(encoder.encode(`o: ${JSON.stringify({ error: `\`\`\`\n${errorMessage}\n\`\`\`` })}\n`))
             controller.close()
           }
         },

apps/backend-convex/package.json

@@ -24,6 +24,7 @@
     "@openrouter/ai-sdk-provider": "^0.7.2",
     "ai": "^4.3.16",
     "convex-helpers": "^0.1.94",
+    "destr": "^2.0.5",
     "hono": "^4.7.11",
     "zod": "^3.25.64"
   },

apps/backend-convex/utils/error.ts

@@ -0,0 +1,22 @@
+import { destr } from 'destr'
+
+export function normalizePossibleSDKError(error: any) {
+  if (error.name === 'AI_APICallError') {
+    return {
+      name: 'AI_APICallError',
+      message: destr<any>(error.responseBody)?.error?.message ?? error.message,
+      cause: error.cause,
+    }
+  }
+
+  return error
+}
+
+import { ConvexError } from 'convex/values'
+
+export function getErrorMessage(error: Error | null) {
+  if (error instanceof ConvexError)
+    return error.data.msg ?? error.data.message ?? error.data.kind ?? error.data ?? error.name
+
+  return error?.message ?? error
+}

apps/frontend/app/utils/convex.ts

@@ -1,8 +1,3 @@
-import { ConvexError } from 'convex/values'
+import { getErrorMessage } from 'backend-convex/utils/error'
 
-export function getConvexErrorMessage(error: Error | null) {
-  if (error instanceof ConvexError)
-    return error.data.msg ?? error.data.message ?? error.data.kind ?? error.data ?? error.name
-
-  return error?.message ?? error
-}
+export { getErrorMessage as getConvexErrorMessage }