/agents-sdk

name: agents-sdk
description: Build, debug, or review Cloudflare Agents SDK applications using the agents package.

Cloudflare Agents SDK

Your knowledge of the Agents SDK may be outdated. **Prefer retrieval over pre-training** for any Agents SDK task.

Retrieval Sources

Cloudflare docs: https://developers.cloudflare.com/agents/

| Topic | Docs URL | Use for | |-------|----------|---------| | Getting started | [Quick start](https://developers.cloudflare.com/agents/getting-started/quick-start/) | First agent, project setup | | Adding to existing project | [Add to existing project](https://developers.cloudflare.com/agents/getting-started/add-to-existing-project/) | Install into existing Workers app | | Configuration | [Configuration](https://developers.cloudflare.com/agents/api-reference/configuration/) | `wrangler.jsonc`, bindings, assets, deployment | | Agent class | [Agents API](https://developers.cloudflare.com/agents/api-reference/agents-api/) | Agent lifecycle, patterns, pitfalls | | State | [Store and sync state](https://developers.cloudflare.com/agents/api-reference/store-and-sync-state/) | `setState`, `validateStateChange`, persistence | | Routing | [Routing](https://developers.cloudflare.com/agents/api-reference/routing/) | URL patterns, `routeAgentRequest` | | Callable methods | [Callable methods](https://developers.cloudflare.com/agents/api-reference/callable-methods/) | `@callable`, RPC, streaming, timeouts | | Scheduling | [Schedule tasks](https://developers.cloudflare.com/agents/api-reference/schedule-tasks/) | `schedule()`, `scheduleEvery()`, cron | | Workflows | [Run workflows](https://developers.cloudflare.com/agents/api-reference/run-workflows/) | `AgentWorkflow`, durable multi-step tasks | | HTTP/WebSockets | [WebSockets](https://developers.cloudflare.com/agents/api-reference/websockets/) | Lifecycle hooks, hibernation | | Chat agents | [Chat agents](https://developers.cloudflare.com/agents/communication-channels/chat/chat-agents/) | `AIChatAgent`, streaming, tools, persistence | | Client SDK | [Client SDK](https://developers.cloudflare.com/agents/communication-channels/chat/client-sdk/) | `useAgent`, `AgentClient`, state, RPC, HTTP | | Client tools | [Client tools](https://developers.cloudflare.com/agents/harnesses/think/client-tools/) | Client-side tools, `autoContinueAfterToolResult` | | Server-driven messages | [Autonomous responses](https://developers.cloudflare.com/agents/communication-channels/chat/autonomous-responses/) | `saveMessages`, `waitUntilStable`, server-initiated turns | | Resumable streaming | [Chat agents](https://developers.cloudflare.com/agents/communication-channels/chat/chat-agents/#resumable-streaming) | Stream recovery on disconnect | | Email | [Email](https://developers.cloudflare.com/agents/api-reference/email/) | Email routing, secure reply resolver | | MCP client | [MCP client](https://developers.cloudflare.com/agents/model-context-protocol/apis/client-api/) | Connecting to MCP servers | | MCP server | [MCP server](https://developers.cloudflare.com/agents/model-context-protocol/apis/handler-api/) | Building MCP servers with `createMcpHandler` | | MCP transports | [MCP transports](https://developers.cloudflare.com/agents/model-context-protocol/protocol/transport/) | Streamable HTTP, SSE, RPC transport options | | Securing MCP servers | [Securing MCP](https://developers.cloudflare.com/agents/model-context-protocol/guides/securing-mcp-server/) | OAuth, proxy MCP, hardening | | Human-in-the-loop | [Human-in-the-loop](https://developers.cloudflare.com/agents/concepts/agentic-patterns/human-in-the-loop/) | Workflow approvals, elicitation, timeout handling | | Durable execution | [Durable execution](https://developers.cloudflare.com/agents/api-reference/durable-execution/) | `runFiber()`, `stash()`, surviving DO eviction | | Queue | [Queue](https://developers.cloudflare.com/agents/api-reference/queue-tasks/) | Built-in FIFO queue, `queue()` | | Retries | [Retries](https://developers.cloudflare.com/agents/api-reference/retries/) | `this.retry()`, backoff/jitter | | Observability | [Observability](https://developers.cloudflare.com/agents/api-reference/observability/) | Diagnostics-channel events | | Push notifications | [Push notifications](https://developers.cloudflare.com/agents/communication-channels/webhooks/push-notifications/) | Web Push + VAPID from agents | | Webhooks | [Webhooks](https://developers.cloudflare.com/agents/communication-channels/webhooks/) | Receiving external webhooks | | Cross-domain auth | [Cross-domain auth](https://developers.cloudflare.com/agents/runtime/operations/cross-domain-authentication/) | WebSocket auth, tokens, CORS | | Readonly connections | [Readonly](https://developers.cloudflare.com/agents/api-reference/readonly-connections/) | `shouldConnectionBeReadonly` | | Voice | [Voice](https://developers.cloudflare.com/agents/api-reference/voice/) | Experimental STT/TTS, `withVoice` | | Browse the web | [Browser tools](https://developers.cloudflare.com/agents/api-reference/browse-the-web/) | Experimental CDP browser automation | | Think | [Think](https://developers.cloudflare.com/agents/api-reference/think/) | Experimental higher-level chat agent class | | Migrations | [AI SDK v5](https://github.com/cloudflare/agents/blob/main/docs/agents/migration-to-ai-sdk-v5.md), [AI SDK v6](https://github.com/cloudflare/agents/blob/main/docs/agents/migration-to-ai-sdk-v6.md) | Upgrading `@cloudflare/ai-chat` |

Capabilities

The Agents SDK provides:

• **Persistent state** — SQLite-backed, auto-synced to clients via `setState`
• **Callable RPC** — `@callable()` methods invoked over WebSocket
• **Scheduling** — One-time, recurring (`scheduleEvery`), and cron tasks
• **Workflows** — Durable multi-step background processing via `AgentWorkflow`
• **Durable execution** — `runFiber()` / `stash()` for work that survives DO eviction
• **Queue** — Built-in FIFO queue with retries via `queue()`
• **Retries** — `this.retry()