Fix/relax schema validation (#232)

* fix: relax zod schemas with passthrough to allow unexpected fields

Add .passthrough() to all zod object schemas to prevent validation failures
when the API returns extra fields that aren't in our schema definitions.

This ensures the provider is forward-compatible with API changes and
doesn't break when new fields are added to responses.

Changes:
- Add .passthrough() to all object schemas in chat/schemas.ts
- Add .passthrough() to all object schemas in completion/schemas.ts
- Add .passthrough() to provider-metadata, image, and reasoning-details schemas
- Add type assertions for error handling to fix TypeScript errors from passthrough

Evidence: All 74 unit tests pass, 10/11 e2e tests pass (1 unrelated failure)

* test: add file parser annotation schema test

Add test to verify FileParser annotations with content arrays parse correctly.
Update error schema tests to expect passthrough fields in output.

Evidence: Test passes with file annotations containing content arrays

* chore: add changeset for schema relaxation

* Add FileParserPlugin with Mistral OCR to PDF test

* Format long lines in file-parser-schema.test.ts

* Replace provider name with generic example in tests

* Replace type cast with ts-expect-error

Author: subtleGradient

.changeset/relax-schemas.md

@@ -0,0 +1,7 @@
+---
+"@openrouter/ai-sdk-provider": patch
+---
+
+Relax zod schemas with passthrough to allow unexpected API fields
+
+Add `.passthrough()` to all zod object schemas to prevent validation failures when the API returns extra fields not in our schema definitions. This ensures forward compatibility with API changes and prevents breaking when new fields are added to responses.

e2e/pdf-blob/index.test.ts

@@ -72,6 +72,14 @@ test('sending large pdf base64 blob with FileParserPlugin', async () => {
   });
 
   const model = openrouter('anthropic/claude-3.5-sonnet', {
+    plugins: [
+      {
+        id: 'file-parser',
+        pdf: {
+          engine: 'mistral-ocr',
+        },
+      },
+    ],
     usage: {
       include: true,
     },

src/chat/file-parser-schema.test.ts

@@ -0,0 +1,112 @@
+import { describe, expect, it } from 'vitest';
+import { OpenRouterNonStreamChatCompletionResponseSchema } from './schemas';
+
+describe('FileParser annotation schema', () => {
+  it('should parse response with all real API fields', () => {
+    // This is based on actual API response structure (anonymized)
+    const response = {
+      id: 'gen-xxx',
+      provider: 'Amazon Bedrock',
+      model: 'anthropic/claude-3.5-sonnet',
+      object: 'chat.completion',
+      created: 1763157299,
+      choices: [
+        {
+          logprobs: null,
+          finish_reason: 'stop',
+          native_finish_reason: 'stop',
+          index: 0,
+          message: {
+            role: 'assistant' as const,
+            content: 'Test response content',
+            refusal: null,
+            reasoning: null,
+            annotations: [
+              {
+                type: 'file' as const,
+                file: {
+                  hash: 'abc123',
+                  name: '',
+                  content: [
+                    {
+                      type: 'text',
+                      text: '<file name="">',
+                    },
+                  ],
+                },
+              },
+            ],
+          },
+        },
+      ],
+      usage: {
+        prompt_tokens: 100,
+        completion_tokens: 50,
+        total_tokens: 150,
+      },
+    };
+
+    const result =
+      OpenRouterNonStreamChatCompletionResponseSchema.parse(response);
+    expect(result).toBeDefined();
+  });
+
+  it('should parse file annotation with content array and extra fields', () => {
+    const response = {
+      id: 'gen-test',
+      provider: 'Amazon Bedrock',
+      model: 'anthropic/claude-3.5-sonnet',
+      object: 'chat.completion',
+      created: 1763157061,
+      choices: [
+        {
+          logprobs: null,
+          finish_reason: 'stop',
+          native_finish_reason: 'stop', // Extra field from API
+          index: 0,
+          message: {
+            role: 'assistant' as const,
+            content: 'Test response',
+            refusal: null, // Extra field from API
+            reasoning: null,
+            annotations: [
+              {
+                type: 'file' as const,
+                file: {
+                  hash: '85bd49b97b7ff5be002d9f654776119f253c1cae333b49ba8f4a53da346284ba',
+                  name: '',
+                  content: [
+                    {
+                      type: 'text',
+                      text: '<file name="">',
+                    },
+                    {
+                      type: 'text',
+                      text: 'Some file content',
+                    },
+                  ],
+                },
+              },
+            ],
+          },
+        },
+      ],
+      usage: {
+        prompt_tokens: 100,
+        completion_tokens: 50,
+        total_tokens: 150,
+      },
+    };
+
+    const result =
+      OpenRouterNonStreamChatCompletionResponseSchema.parse(response);
+
+    // Check that parsing succeeded
+    expect(result).toBeDefined();
+    // The schema uses passthrough so we can't strictly type check, but we can verify structure
+    // @ts-expect-error test intentionally inspects passthrough data
+    const firstChoice = result.choices?.[0];
+    expect(firstChoice?.message.annotations).toBeDefined();
+    expect(firstChoice?.message.annotations?.[0]?.type).toBe('file');
+  });
+});

src/chat/index.ts

@@ -234,16 +234,20 @@ export class OpenRouterChatLanguageModel implements LanguageModelV2 {
 
     // Check if response is an error (HTTP 200 with error payload)
     if ('error' in responseValue) {
+      const errorData = responseValue.error as {
+        message: string;
+        code?: string;
+      };
       throw new APICallError({
-        message: responseValue.error.message,
+        message: errorData.message,
         url: this.config.url({
           path: '/chat/completions',
           modelId: this.modelId,
         }),
         requestBodyValues: args,
         statusCode: 200,
         responseHeaders,
-        data: responseValue.error,
+        data: errorData,
       });
     }