Chat SDK is an open-source TypeScript framework designed to help developers build chatbots and conversational agents that can operate across multiple messaging platforms using a unified codebase. It abstracts away the differences between platforms such as Slack, Microsoft Teams, Google Chat, Discord, Telegram, GitHub, and others, allowing developers to write bot logic once and deploy it everywhere.

The SDK is built around an event-driven architecture, where developers define handlers for events like mentions, messages, reactions, and interactions. These handlers are triggered consistently regardless of the underlying platform, simplifying cross-platform bot development.

Chat SDK introduces three main concepts: a central Chat controller that routes events, platform-specific adapters that handle integrations, and a pluggable state layer for persistence and thread management. This structure enables scalable, serverless-ready chatbot systems with support for distributed state and multi-turn conversations.

A key strength of the SDK is its multi-platform support, enabling bots to run on services like Slack, Discord, and Teams without rewriting integrations. It also includes features such as AI streaming support, JSX-based UI components (cards, buttons, modals), and type-safe APIs for improved developer experience.

The platform is particularly useful for building AI-powered assistants, support bots, internal tools, and automation workflows that need to operate across different communication channels. By unifying APIs and event handling, Chat SDK reduces complexity and accelerates development of cross-platform conversational applications.

Key features include:

• Unified API for building chatbots across multiple platforms
• Event-driven architecture for handling messages, mentions, and reactions
• Type-safe TypeScript support with adapters and handlers
• AI streaming support for real-time LLM responses
• Pluggable state management for persistence and multi-turn conversations

Common use cases include:

• Building AI assistants
• Customer support bots
• Internal automation tools
• Developer bots for GitHub or Slack
• Cross-platform messaging workflows.

Chat SDK is developed by Vercel as part of its broader ecosystem for building AI-powered and event-driven applications.