Chat SDK

Chat SDK is an open-source TypeScript library from Vercel for building chat bots and agents that run on multiple messaging platforms from one codebase. Developers write handlers once and connect them to platforms through adapters. It is distributed on npm as chat and released under the MIT license.

What It Is

Chat SDK is a unified chat layer that hides the differences between platform APIs, webhook formats and message formats behind adapters. A Chat instance coordinates adapters and routes incoming events to typed handlers. A pluggable state layer persists thread subscriptions and distributed locks. Redis, Postgres and in-memory state are mentioned on the homepage.

Handlers cover mentions, messages, reactions, button clicks, slash commands and modals. Cards, buttons and modals are written in JSX and rendered natively on each platform, for example as Block Kit, Adaptive Cards or Google Chat Cards.

Adapters and Platforms

The adapter catalog lists official adapters for Slack, Teams, Google Chat, Gmail, Discord, WhatsApp, Twilio, Messenger, Instagram, X, Twitch, GitHub, GitLab, Linear, Notion and Telegram. Vendor-official and community adapters are also supported, and the docs explain how to build a new adapter. A dependency-free @chat-adapter/catalog package lists adapters with their capabilities, peer dependencies and environment variables.

Building AI Agents

The SDK can stream LLM responses into a thread, using native Slack streaming, Telegram private chat draft previews, or a post-and-edit fallback. It ships AI utilities, including agent tools, and works with Vercel's AI SDK, AI Gateway, Sandbox and Workflows. Guides cover authenticating a Slack bot with Vercel Connect, a knowledge agent template and an eve integration.

Setup Path

Install with npm i chat plus the adapters you need. Alternatively, run npx create-chat-sdk@latest to scaffold a Next.js bot app with a Chat configuration, webhook route and .env.example. Adapter credentials are read from environment variables. For AI coding agents, a Chat SDK skill can be installed with npx skills add vercel/chat, and the docs are available as llms.txt.