fix: improve error handling (#28)

* fix(error-handling): improve error message extraction from runpod api responses

- create centralized error handler following fal/replicate/elevenlabs patterns
- extract actual error messages instead of generic fallbacks
- parse nested json in image api errors for cleaner messages
- prefer message field over error field when available
- export runpodimageerrordata type for users

* chore: add changeset for error handling improvements

Author: TimPietruskyRunPod

.changeset/improve-error-handling.md

@@ -0,0 +1,6 @@
+---
+"@runpod/ai-sdk-provider": patch
+---
+
+Improve error message extraction from Runpod API responses. Users now see actual error messages from the API instead of generic fallbacks like "Unknown error". The error handler extracts nested JSON messages from image API errors and properly surfaces all error details.
+

src/index.ts

@@ -4,3 +4,4 @@ export type { RunpodChatModelId } from './runpod-chat-options';
 export type { RunpodCompletionModelId } from './runpod-completion-options';
 export type { RunpodImageModelId } from './runpod-image-options';
 export type { OpenAICompatibleErrorData as RunpodErrorData } from '@ai-sdk/openai-compatible';
+export type { RunpodImageErrorData } from './runpod-error';

src/runpod-error.ts

@@ -0,0 +1,44 @@
+import { z } from 'zod';
+import { createJsonErrorResponseHandler } from '@ai-sdk/provider-utils';
+
+// Runpod image API error schema (supports both error formats)
+export const runpodImageErrorSchema = z.object({
+  error: z.string().optional(),
+  message: z.string().optional(),
+});
+
+export type RunpodImageErrorData = z.infer<typeof runpodImageErrorSchema>;
+
+export const runpodImageFailedResponseHandler = createJsonErrorResponseHandler({
+  errorSchema: runpodImageErrorSchema as any,
+  errorToMessage: (data: RunpodImageErrorData) => {
+    // Prefer message if available (more descriptive)
+    if (data.message) {
+      return data.message;
+    }
+    
+    // If error field exists, try to extract nested JSON message
+    if (data.error) {
+      // Runpod sometimes returns nested JSON in the error field like:
+      // "Error submitting task: 400, {\"code\":400,\"message\":\"...\"}"
+      // Try to extract the inner message for cleaner error messages
+      // Find the last occurrence of { which likely starts the JSON object
+      const lastBraceIndex = data.error.lastIndexOf('{');
+      if (lastBraceIndex !== -1) {
+        try {
+          const jsonStr = data.error.substring(lastBraceIndex);
+          const nestedError = JSON.parse(jsonStr);
+          if (nestedError.message && typeof nestedError.message === 'string') {
+            return nestedError.message;
+          }
+        } catch {
+          // If parsing fails, fall back to the original error string
+        }
+      }
+      return data.error;
+    }
+    
+    return 'Unknown Runpod error';
+  },
+});
+

src/runpod-image-model.ts

@@ -2,14 +2,14 @@ import { ImageModelV2, ImageModelV2CallWarning } from '@ai-sdk/provider';
 import {
   combineHeaders,
   createJsonResponseHandler,
-  createJsonErrorResponseHandler,
   createBinaryResponseHandler,
   FetchFunction,
   postJsonToApi,
   getFromApi,
 } from '@ai-sdk/provider-utils';
 import { InvalidArgumentError } from '@ai-sdk/provider';
 import { z } from 'zod';
+import { runpodImageFailedResponseHandler } from './runpod-error';
 
 /* eslint-disable @typescript-eslint/no-explicit-any */
 interface RunpodImageModelConfig {
@@ -136,10 +136,8 @@ export class RunpodImageModel implements ImageModelV2 {
       headers: combineHeaders(this.config.headers(), headers),
       body: {
         input: inputPayload,
-      },      failedResponseHandler: createJsonErrorResponseHandler({
-        errorSchema: runpodImageErrorSchema as any,
-        errorToMessage: (data: any) => data.error ?? 'Unknown error',
-      }),
+      },
+      failedResponseHandler: runpodImageFailedResponseHandler,
       successfulResponseHandler: createJsonResponseHandler(
         runpodImageResponseSchema as any
       ),
@@ -226,10 +224,7 @@ export class RunpodImageModel implements ImageModelV2 {
     const { value: imageData } = await getFromApi({
       url: imageUrl,
       successfulResponseHandler: createBinaryResponseHandler(),
-      failedResponseHandler: createJsonErrorResponseHandler({
-        errorSchema: runpodImageErrorSchema as any,
-        errorToMessage: (data: any) => data.error ?? 'Failed to download image',
-      }),
+      failedResponseHandler: runpodImageFailedResponseHandler,
       abortSignal,
       fetch: this.config.fetch,
     });
@@ -255,11 +250,7 @@ export class RunpodImageModel implements ImageModelV2 {
         successfulResponseHandler: createJsonResponseHandler(
           runpodImageStatusSchema as any
         ),
-        failedResponseHandler: createJsonErrorResponseHandler({
-          errorSchema: runpodImageErrorSchema as any,
-          errorToMessage: (data: any) =>
-            data.error ?? 'Failed to check job status',
-        }),
+        failedResponseHandler: runpodImageFailedResponseHandler,
         abortSignal,
         fetch: this.config.fetch,
       });
@@ -377,9 +368,3 @@ const runpodImageStatusSchema = z.object({
     .optional(),
   error: z.string().optional(), // Error message if FAILED
 });
-
-// Runpod image API error schema
-const runpodImageErrorSchema = z.object({
-  error: z.string(),
-  message: z.string().optional(),
-});