Overview

TanStack AI is a lightweight, type-safe SDK for building production-ready AI experiences. Its framework-agnostic core provides type-safe tool/function calling, streaming responses, and first-class React and Solid integrations, with adapters for multiple LLM providers — enabling predictable, composable, and testable AI features across any stack.

• ✅ Type-Safe - Full TypeScript support with Zod schema inference
• ✅ Streaming - Built-in streaming support for real-time responses
• ✅ Isomorphic Tools - Define once with toolDefinition(), implement with .server() or .client()
• ✅ Framework Agnostic - Core library works anywhere
• ✅ Multiple Providers - OpenRouter, OpenAI, Anthropic, Gemini, Ollama, and more
• ✅ Approval Flow - Built-in support for tool approval workflows
• ✅ Automatic Execution - Both server and client tools execute automatically

The framework-agnostic core of TanStack AI provides the building blocks for creating AI experiences in any environment, including:

• Next.js - API routes and App Router
• TanStack Start - React Start or Solid Start (recommended!)
• Express - Node.js server
• React Router v7 - Loaders and actions

TanStack AI lets you define a tool once and provide environment-specific implementations. Using toolDefinition() to declare the tool's input/output types and the server behavior with .server() (or a client implementation with .client()). These isomorphic tools can be invoked from the AI runtime regardless of framework.

import { chat } from '@tanstack/ai'
import { toolDefinition } from '@tanstack/ai'
import { openaiText } from '@tanstack/ai-openai'

// Define a tool
const getProductsDef = toolDefinition({
  name: 'getProducts',
  inputSchema: z.object({ query: z.string() }),
  outputSchema: z.array(z.object({ id: z.string(), name: z.string() })),
})

// Create server implementation
const getProducts = getProductsDef.server(async ({ query }) => {
  return await db.products.search(query)
})

// Use in AI chat
chat({
  adapter: openaiText('gpt-5.2'),
  messages: [{ role: 'user', content: 'Find products' }],
  tools: [getProducts]
})

The TanStack AI ecosystem consists of several packages:

The core AI library that provides:

• AI adapter interface for connecting to LLM providers
• Chat completion and streaming
• Isomorphic tool/function calling system
• Agent loop strategies
• Type-safe tool definitions with toolDefinition()
• Type-safe Model Options based on adapter & model selection
• Type-safe content modalities (text, image, audio, video, document) based on model capabilities

A framework-agnostic headless client for managing chat state:

• Message management with full type safety
• Streaming support
• Connection adapters (SSE, HTTP stream, custom)
• Automatic tool execution (server and client)
• Tool approval flow handling

React hooks for TanStack AI:

• useChat hook for chat interfaces
• Automatic state management
• Tool approval flow support
• Type-safe message handling with InferChatMessages

Solid hooks for TanStack AI:

• useChat hook for chat interfaces
• Automatic state management
• Tool approval flow support
• Type-safe message handling with InferChatMessages

With the help of adapters, TanStack AI can connect to various LLM providers. Available adapters include:

• @tanstack/ai-openrouter - OpenRouter (300+ models via a single API key — recommended)
• @tanstack/ai-openai - OpenAI (GPT series)
• @tanstack/ai-anthropic - Anthropic (Claude)
• @tanstack/ai-gemini - Google Gemini
• @tanstack/ai-ollama - Ollama (local models)
• @tanstack/ai-groq - Groq
• @tanstack/ai-grok - xAI Grok
• @tanstack/ai-fal - fal (image & video generation)

• Quick Start Guide - Get up and running in minutes
• Tools Guide - Learn about the isomorphic tool system
• API Reference - Explore the full API