adk-llm-bridge

adk-llm-bridge

Use any LLM with Google ADK TypeScript in just a few lines of code.

Why?

Google ADK TypeScript comes with built-in Gemini support. This bridge extends it to work with any model from providers like Anthropic, OpenAI, Meta, and more—while keeping all ADK features like multi-agent orchestration, tool calling, and streaming.

Key Benefits

• Simple — 3 lines to integrate any model
• Battle-tested — Built on the official OpenAI and Anthropic SDKs
• Compatible — Works with any OpenAI-compatible API (AI Gateway, OpenRouter, etc.)

Supported Providers

Provider	Models	Features
Vercel AI Gateway	100+ models (Claude, GPT, Llama, Gemini, etc.)	Simple, fast
OpenRouter	100+ models	Provider routing, fallbacks, price optimization
OpenAI	GPT-4, o1, o3, etc.	Direct API access
Anthropic	Claude models	Direct API access
xAI	Grok models	Direct API access
Custom (OpenAI-compatible)	Any model	Ollama, vLLM, Azure OpenAI, LM Studio, etc.

Installation

bun add adk-llm-bridge @google/adk

pnpm add adk-llm-bridge @google/adk

npm install adk-llm-bridge @google/adk

Quick Start

import { LlmAgent } from '@google/adk';
import { AIGateway } from 'adk-llm-bridge';

const agent = new LlmAgent({
  name: 'assistant',
  model: AIGateway('anthropic/claude-sonnet-4'),
  instruction: 'You are a helpful assistant.',
});

That's it. All ADK features work: tools, streaming, multi-agent, etc.

Other Providers

import { OpenRouter, OpenAI, Anthropic, XAI, Custom } from 'adk-llm-bridge';

// OpenRouter - 100+ models with routing
model: OpenRouter('anthropic/claude-sonnet-4')

// OpenAI - Direct API
model: OpenAI('gpt-4.1')

// Anthropic - Direct API  
model: Anthropic('claude-sonnet-4-5')

// xAI - Direct API
model: XAI('grok-3-beta')

// Local models (LM Studio, Ollama, etc.)
model: Custom('your-model', { baseURL: 'http://localhost:1234/v1' })

See the examples directory for complete implementations.

Using LLMRegistry (Alternative)

You can also register providers with ADK's LLMRegistry to use string-based model names:

import { LlmAgent, LLMRegistry } from '@google/adk';
import { AnthropicLlm } from 'adk-llm-bridge';

LLMRegistry.register(AnthropicLlm);

const agent = new LlmAgent({
  name: 'assistant',
  model: 'claude-sonnet-4-5',  // String-based model name
  instruction: 'You are a helpful assistant.',
});

Configuration

Environment Variables

AI Gateway:

AI_GATEWAY_API_KEY=your-api-key
AI_GATEWAY_URL=https://ai-gateway.vercel.sh/v1  # optional

OpenRouter:

OPENROUTER_API_KEY=your-api-key
OPENROUTER_SITE_URL=https://your-site.com  # optional, for ranking
OPENROUTER_APP_NAME=Your App Name          # optional, for ranking

Direct Providers:

OPENAI_API_KEY=your-openai-key
ANTHROPIC_API_KEY=your-anthropic-key
XAI_API_KEY=your-xai-key

Programmatic Configuration

Pass options directly to the factory functions:

import { AIGateway, OpenRouter, Anthropic } from 'adk-llm-bridge';

// AI Gateway with custom URL
model: AIGateway('anthropic/claude-sonnet-4', {
  apiKey: process.env.MY_API_KEY,
  baseURL: 'https://my-gateway.example.com/v1',
})

// OpenRouter with site info
model: OpenRouter('anthropic/claude-sonnet-4', {
  apiKey: process.env.OPENROUTER_API_KEY,
  siteUrl: 'https://your-site.com',
  appName: 'Your App',
})

// Anthropic with custom max tokens
model: Anthropic('claude-sonnet-4-5', {
  apiKey: process.env.ANTHROPIC_API_KEY,
  maxTokens: 8192,
})

Model Format

Use the provider/model format:

anthropic/claude-sonnet-4
openai/gpt-5
google/gemini-3-flash
meta/llama-4-maverick
mistral/mistral-large-3
xai/grok-4.1
deepseek/deepseek-chat

Popular Models

Provider	Models
Anthropic	anthropic/claude-sonnet-4, anthropic/claude-opus-4.5
OpenAI	openai/gpt-5, openai/gpt-5-mini, openai/o3
Google	google/gemini-3-flash, google/gemini-3-pro, google/gemini-2.5-pro
Meta	meta/llama-4-maverick, meta/llama-4-scout, meta/llama-3.3-70b-instruct
Mistral	mistral/mistral-large-3, mistral/ministral-3-14b
xAI	xai/grok-4.1, xai/grok-4, xai/grok-3
DeepSeek	deepseek/deepseek-chat, deepseek/deepseek-reasoner

Browse all models:

• Vercel AI Gateway Models
• OpenRouter Models

Features

• Text generation - Simple prompt/response
• Streaming - Real-time token streaming
• Tool calling - Function calling with automatic conversion
• Multi-turn - Full conversation history support
• Multi-agent - Sub-agents and agent transfer
• Usage metadata - Token counts for monitoring

Tool Calling Example

import { FunctionTool, LlmAgent } from '@google/adk';
import { Anthropic } from 'adk-llm-bridge';
import { z } from 'zod';

const getWeather = new FunctionTool({
  name: 'get_weather',
  description: 'Get current weather for a city',
  parameters: z.object({
    city: z.string().describe('City name'),
  }),
  execute: ({ city }) => {
    return { status: 'success', weather: 'sunny', city };
  },
});

const agent = new LlmAgent({
  name: 'weather-assistant',
  model: Anthropic('claude-sonnet-4-5'),
  instruction: 'You help users check the weather.',
  tools: [getWeather],
});

API Reference

Factory Functions

Function	Description
AIGateway(model, options?)	Vercel AI Gateway (100+ models)
OpenRouter(model, options?)	OpenRouter (100+ models)
OpenAI(model, options?)	OpenAI direct API
Anthropic(model, options?)	Anthropic direct API
XAI(model, options?)	xAI direct API
Custom(model, options)	Any OpenAI-compatible API

Configuration Options

AIGateway:

Option	Type	Default	Description
apiKey	string	process.env.AI_GATEWAY_API_KEY	API key
baseURL	string	https://ai-gateway.vercel.sh/v1	Gateway URL
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

**OpenRouter:

Option	Type	Default	Description
apiKey	string	process.env.OPENROUTER_API_KEY	API key
baseURL	string	https://openrouter.ai/api/v1	API URL
siteUrl	string	process.env.OPENROUTER_SITE_URL	Your site URL (for ranking)
appName	string	process.env.OPENROUTER_APP_NAME	Your app name (for ranking)
provider	object	-	Provider routing preferences
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

**OpenAI:

Option	Type	Default	Description
apiKey	string	process.env.OPENAI_API_KEY	API key
organization	string	process.env.OPENAI_ORGANIZATION	Organization ID
project	string	process.env.OPENAI_PROJECT	Project ID
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

**Anthropic:

Option	Type	Default	Description
apiKey	string	process.env.ANTHROPIC_API_KEY	API key
maxTokens	number	4096	Max tokens in response
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

**XAI:

Option	Type	Default	Description
apiKey	string	process.env.XAI_API_KEY	API key
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

**Custom:

Option	Type	Default	Description
model	string	-	Model name (required)
baseURL	string	-	API base URL (required)
name	string	"custom"	Provider name for logs/errors
apiKey	string	-	API key for authentication
headers	Record<string, string>	-	Additional HTTP headers
queryParams	Record<string, string>	-	Query parameters for all requests
providerOptions	Record<string, unknown>	-	Additional options for request body
timeout	number	60000	Request timeout (ms)
maxRetries	number	2	Max retry attempts

Examples

See the examples directory:

• basic-agent-ai-gateway - Multi-agent HelpDesk with AI Gateway
• basic-agent-openrouter - Multi-agent HelpDesk with OpenRouter
• basic-agent-openai - Multi-agent HelpDesk with OpenAI
• basic-agent-anthropic - Multi-agent HelpDesk with Anthropic
• basic-agent-xai - Multi-agent HelpDesk with xAI
• basic-agent-lmstudio - Multi-agent HelpDesk with LM Studio
• express-server - Production HTTP API with sessions, streaming, tools

Requirements

• Node.js >= 18.0.0
• @google/adk >= 0.2.2

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

MIT