Cloudflare Agents SDK

Cloudflare Agents SDK

Build persistent, stateful AI agents on Cloudflare Workers using the agents npm package.

FIRST: Verify Installation

npm install agents

Agents require a binding in wrangler.jsonc:

{
  "durable_objects": {
    // "class_name" must match your Agent class name exactly
    "bindings": [{ "name": "Counter", "class_name": "Counter" }]
  },
  "migrations": [
    // Required: list all Agent classes for SQLite storage
    { "tag": "v1", "new_sqlite_classes": ["Counter"] }
  ]
}

Choosing an Agent Type

Key Concepts

• Agent base class provides state, scheduling, RPC, MCP, and email capabilities
• AIChatAgent adds streaming chat with automatic message persistence and resumable streams
• Code Mode generates executable code instead of tool calls—reduces token usage significantly
• this.state / this.setState() - automatic persistence to SQLite, broadcasts to clients
• this.schedule() - schedule tasks at Date, delay (seconds), or cron expression