agents-sdk

# Cloudflare Agents SDK Your knowledge of the Agents SDK may be outdated. **Prefer retrieval over pre-training** for any Agents SDK task. ## Retrieval Sources Fetch current docs from `https://github.com/cloudflare/agents/tree/main/docs` before implementing. | Topic | Doc | Use for | |-------|-----|---------| | Getting started | `docs/getting-started.md` | First agent, project setup | | State | `docs/state.md` | `setState`, `validateStateChange`, persistence | | Routing | `docs/routing.md` | URL patterns, `routeAgentRequest`, `basePath` | | Callable methods | `docs/callable-methods.md` | `@callable`, RPC, streaming, timeouts | | Scheduling | `docs/scheduling.md` | `schedule()`, `scheduleEvery()`, cron | | Workflows | `docs/workflows.md` | `AgentWorkflow`, durable multi-step tasks | | HTTP/WebSockets | `docs/http-websockets.md` | Lifecycle hooks, hibernation | | Email | `docs/email.md` | Email routing, secure reply resolver | | MCP client | `docs/mcp-client.md` | Connecting to MCP servers | | MCP server | `docs/mcp-servers.md` | Building MCP servers with `McpAgent` | | Client SDK | `docs/client-sdk.md` | `useAgent`, `useAgentChat`, React hooks | | Human-in-the-loop | `docs/human-in-the-loop.md` | Approval flows, pausing workflows | | Resumable streaming | `docs/resumable-streaming.md` | Stream recovery on disconnect | Cloudflare docs: https://developers.cloudflare.com/agents/ ## Capabilities The Agents SDK provides: - **Persistent state** - SQLite-backed, auto-synced to clients - **Callable RPC** - `@callable()` methods invoked over WebSocket - **Scheduling** - One-time, recurring (`scheduleEvery`), and cron tasks - **Workflows** - Durable multi-step background processing via `AgentWorkflow` - **MCP integration** - Connect to MCP servers or build your own with `McpAgent` - **Email handling** - Receive and reply to emails with secure routing - **Streaming chat** - `AIChatAgent` with resumable streams - **React hooks** - `useAgent`, `useAgentChat` for client apps ## FIRST: Verify Installation ```bash npm ls agents # Should show agents package ``` If not installed: ```bash npm install agents ``` ## Wrangler Configuration ```jsonc { "durable_objects": { "bindings": [{ "name": "MyAgent", "class_name": "MyAgent" }] }, "migrations": [{ "tag": "v1", "new_sqlite_classes": ["MyAgent"] }] } ``` ## Agent Class ```typescript import { Agent, routeAgentRequest, callable } from "agents"; type State = { count: number }; export class Counter extends Agent<Env, State> { initialState = { count: 0 }; // Validation hook - runs before state persists (sync, throwing rejects the update) validateStateChange(nextState: State, source: Connection | "server") { if (nextState.count < 0) throw new Error("Count cannot be negative"); } // Notification hook - runs after state persists (async, non-blocking) onStateUpdate(state: State, source: Connection | "server") { console.log("State updated:", state); } @callable() increment() { this.setState({ count: this.state.count + 1 }); return this.state.count; } } export default { fetch: (req, env) => routeAgentRequest(req, env) ?? new Response("Not found", { status: 404 }) }; ``` ## Routing Requests route to `/agents/{agent-name}/{instance-name}`: | Class | URL | |-------|-----| | `Counter` | `/agents/counter/user-123` | | `ChatRoom` | `/agents/chat-room/lobby` | Client: `useAgent({ agent: "Counter", name: "user-123" })` ## Core APIs | Task | API | |------|-----| | Read state | `this.state.count` | | Write state | `this.setState({ count: 1 })` | | SQL query | `` this.sql`SELECT * FROM users WHERE id = ${id}` `` | | Schedule (delay) | `await this.schedule(60, "task", payload)` | | Schedule (cron) | `await this.schedule("0 * * * *", "task", payload)` | | Schedule (interval) | `await this.scheduleEvery(30, "poll")` | | RPC method | `@callable() myMethod() { ... }` | | Streaming RPC | `@callable({ streaming: true }) stream(res) { ... }` | | Start workflow | `await this.runWorkflow("ProcessingWorkflow", params)` | ## React Client ```tsx import { useAgent } from "agents/react"; function App() { const [state, setLocalState] = useState({ count: 0 }); const agent = useAgent({ agent: "Counter", name: "my-instance", onStateUpdate: (newState) => setLocalState(newState), onIdentity: (name, agentType) => console.log(`Connected to ${name}`) }); return ( <button onClick={() => agent.setState({ count: state.count + 1 })}> Count: {state.count} </button> ); } ``` ## References - **[references/workflows.md](references/workflows.md)** - Durable Workflows integration - **[references/callable.md](references/callable.md)** - RPC methods, streaming, timeouts - **[references/state-scheduling.md](references/state-scheduling.md)** - State persistence, scheduling - **[references/streaming-chat.md](references/streaming-chat.md)** - AIChatAgent, resumable streams - **[references/mcp.md](references/mcp.md)** - MCP server integration - **[references/email.md](references/email.md)** - Email routing and handling - **[references/codemode.md](references/codemode.md)** - Code Mode (experimental)