OpenRouter Provider for Vercel AI SDK

The OpenRouter provider for the Vercel AI SDK gives access to over 300 large language models on the OpenRouter chat and completion APIs.

Setup for AI SDK v5

# For pnpm
pnpm add @openrouter/ai-sdk-provider

# For npm
npm install @openrouter/ai-sdk-provider

# For yarn
yarn add @openrouter/ai-sdk-provider

(LEGACY) Setup for AI SDK v4

# For pnpm
pnpm add @openrouter/ai-sdk-provider@ai-sdk-v4

# For npm
npm install @openrouter/ai-sdk-provider@ai-sdk-v4

# For yarn
yarn add @openrouter/ai-sdk-provider@ai-sdk-v4

Provider Instance

You can import the default provider instance openrouter from @openrouter/ai-sdk-provider:

import { openrouter } from '@openrouter/ai-sdk-provider';

Example

import { openrouter } from '@openrouter/ai-sdk-provider';
import { generateText } from 'ai';

const { text } = await generateText({
  model: openrouter('openai/gpt-4o'),
  prompt: 'Write a vegetarian lasagna recipe for 4 people.',
});

Supported models

This list is not a definitive list of models supported by OpenRouter, as it constantly changes as we add new models (and deprecate old ones) to our system. You can find the latest list of models supported by OpenRouter here.

You can find the latest list of tool-supported models supported by OpenRouter here. (Note: This list may contain models that are not compatible with the AI SDK.)

Passing Extra Body to OpenRouter

There are 3 ways to pass extra body to OpenRouter:

1. Via the providerOptions.openrouter property:

   import { createOpenRouter } from '@openrouter/ai-sdk-provider';
   import { streamText } from 'ai';
   
   const openrouter = createOpenRouter({ apiKey: 'your-api-key' });
   const model = openrouter('anthropic/claude-3.7-sonnet:thinking');
   await streamText({
     model,
     messages: [{ role: 'user', content: 'Hello' }],
     providerOptions: {
       openrouter: {
         reasoning: {
           max_tokens: 10,
         },
       },
     },
   });

2. Via the extraBody property in the model settings:

   import { createOpenRouter } from '@openrouter/ai-sdk-provider';
   import { streamText } from 'ai';
   
   const openrouter = createOpenRouter({ apiKey: 'your-api-key' });
   const model = openrouter('anthropic/claude-3.7-sonnet:thinking', {
     extraBody: {
       reasoning: {
         max_tokens: 10,
       },
     },
   });
   await streamText({
     model,
     messages: [{ role: 'user', content: 'Hello' }],
   });

3. Via the extraBody property in the model factory.

   import { createOpenRouter } from '@openrouter/ai-sdk-provider';
   import { streamText } from 'ai';
   
   const openrouter = createOpenRouter({
     apiKey: 'your-api-key',
     extraBody: {
       reasoning: {
         max_tokens: 10,
       },
     },
   });
   const model = openrouter('anthropic/claude-3.7-sonnet:thinking');
   await streamText({
     model,
     messages: [{ role: 'user', content: 'Hello' }],
   });

Anthropic Prompt Caching

You can include Anthropic-specific options directly in your messages when using functions like streamText. The OpenRouter provider will automatically convert these messages to the correct format internally.

Basic Usage

import { createOpenRouter } from '@openrouter/ai-sdk-provider';
import { streamText } from 'ai';

const openrouter = createOpenRouter({ apiKey: 'your-api-key' });
const model = openrouter('anthropic/<supported-caching-model>');

await streamText({
  model,
  messages: [
    {
      role: 'system',
      content:
        'You are a podcast summary assistant. You are detail-oriented and critical about the content.',
    },
    {
      role: 'user',
      content: [
        {
          type: 'text',
          text: 'Given the text body below:',
        },
        {
          type: 'text',
          text: `<LARGE BODY OF TEXT>`,
          providerOptions: {
            openrouter: {
              cacheControl: { type: 'ephemeral' },
            },
          },
        },
        {
          type: 'text',
          text: 'List the speakers?',
        },
      ],
    },
  ],
});

Anthropic Beta Features

You can enable Anthropic beta features by passing custom headers through the OpenRouter SDK.

Fine-grained Tool Streaming

Fine-grained tool streaming allows streaming tool parameters without buffering, reducing latency for large schemas. This is particularly useful when working with large nested JSON structures.

Important: This is a beta feature from Anthropic. Make sure to evaluate responses before using in production.

Basic Usage

import { createOpenRouter } from '@openrouter/ai-sdk-provider';
import { streamObject } from 'ai';

const provider = createOpenRouter({
  apiKey: process.env.OPENROUTER_API_KEY,
  headers: {
    'anthropic-beta': 'fine-grained-tool-streaming-2025-05-14',
  },
});

const model = provider.chat('anthropic/claude-sonnet-4');

const result = await streamObject({
  model,
  schema: yourLargeSchema,
  prompt: 'Generate a complex object...',
});

for await (const partialObject of result.partialObjectStream) {
  console.log(partialObject);
}

You can also pass the header at the request level:

import { createOpenRouter } from '@openrouter/ai-sdk-provider';
import { generateText } from 'ai';

const provider = createOpenRouter({
  apiKey: process.env.OPENROUTER_API_KEY,
});

const model = provider.chat('anthropic/claude-sonnet-4');

await generateText({
  model,
  prompt: 'Hello',
  headers: {
    'anthropic-beta': 'fine-grained-tool-streaming-2025-05-14',
  },
});

Note: Fine-grained tool streaming is specific to Anthropic models. When using models from other providers, the header will be ignored.

Use Case: Large Component Generation

This feature is particularly beneficial when streaming large, nested JSON structures like UI component trees:

import { createOpenRouter } from '@openrouter/ai-sdk-provider';
import { streamObject } from 'ai';
import { z } from 'zod';

const componentSchema = z.object({
  type: z.string(),
  props: z.record(z.any()),
  children: z.array(z.lazy(() => componentSchema)).optional(),
});

const provider = createOpenRouter({
  apiKey: process.env.OPENROUTER_API_KEY,
  headers: {
    'anthropic-beta': 'fine-grained-tool-streaming-2025-05-14',
  },
});

const model = provider.chat('anthropic/claude-sonnet-4');

const result = await streamObject({
  model,
  schema: componentSchema,
  prompt: 'Create a responsive dashboard layout',
});

for await (const partialComponent of result.partialObjectStream) {
  console.log('Partial component:', partialComponent);
}

Use Cases

Debugging API Requests

The provider supports a debug mode that echoes back the request body sent to the upstream provider. This is useful for troubleshooting and understanding how your requests are being processed. Note that debug mode only works with streaming requests.

import { createOpenRouter } from '@openrouter/ai-sdk-provider';
import { streamText } from 'ai';

const openrouter = createOpenRouter({ apiKey: 'your-api-key' });
const model = openrouter('anthropic/claude-3.5-sonnet', {
  debug: {
    echo_upstream_body: true,
  },
});

const result = await streamText({
  model,
  prompt: 'Hello, how are you?',
});

// The debug data is available in the stream's first chunk
// and in the final response's providerMetadata
for await (const chunk of result.fullStream) {
  // Debug chunks have empty choices and contain debug.echo_upstream_body
  console.log(chunk);
}

The debug response will include the request body that was sent to the upstream provider, with sensitive data redacted (user IDs, base64 content, etc.). This helps you understand how OpenRouter transforms your request before sending it to the model provider.

Usage Accounting

The provider supports OpenRouter usage accounting, which allows you to track token usage details directly in your API responses, without making additional API calls.

// Enable usage accounting
const model = openrouter('openai/gpt-3.5-turbo', {
  usage: {
    include: true,
  },
});

// Access usage accounting data
const result = await generateText({
  model,
  prompt: 'Hello, how are you today?',
});

// Provider-specific usage details (available in providerMetadata)
if (result.providerMetadata?.openrouter?.usage) {
  console.log('Cost:', result.providerMetadata.openrouter.usage.cost);
  console.log(
    'Total Tokens:',
    result.providerMetadata.openrouter.usage.totalTokens,
  );
}

It also supports BYOK (Bring Your Own Key) usage accounting, which allows you to track passthrough costs when you are using a provider's own API key in your OpenRouter account.

// Assuming you have set an OpenAI API key in https://openrouter.ai/settings/integrations

// Enable usage accounting
const model = openrouter('openai/gpt-3.5-turbo', {
  usage: {
    include: true,
  },
});

// Access usage accounting data
const result = await generateText({
  model,
  prompt: 'Hello, how are you today?',
});

// Provider-specific BYOK usage details (available in providerMetadata)
if (result.providerMetadata?.openrouter?.usage) {
  const costDetails = result.providerMetadata.openrouter.usage.costDetails;
  if (costDetails) {
    console.log('BYOK cost:', costDetails.upstreamInferenceCost);
  }
  console.log('OpenRouter credits cost:', result.providerMetadata.openrouter.usage.cost);
  console.log(
    'Total Tokens:',
    result.providerMetadata.openrouter.usage.totalTokens,
  );
}