Agents SDK v0.3.7: Workflows integration, synchronous state, and scheduleEvery()

The latest release of the Agents SDK brings first-class support for Cloudflare Workflows, synchronous state management, and new scheduling capabilities.

Cloudflare Workflows integration

Agents excel at real-time communication and state management. Workflows excel at durable execution. Together, they enable powerful patterns where Agents handle WebSocket connections while Workflows handle long-running tasks, retries, and human-in-the-loop flows.

Use the new AgentWorkflow class to define workflows with typed access to your Agent:

import { AgentWorkflow } from "agents/workflows"; export class ProcessingWorkflow extends AgentWorkflow { async run(event, step) { // Call Agent methods via RPC await this.agent.updateStatus(event.payload.taskId, "processing"); // Non-durable: progress reporting to clients await this.reportProgress({ step: "process", percent: 0.5 }); this.broadcastToClients({ type: "update", taskId: event.payload.taskId }); // Durable via step: idempotent, won't repeat on retry await step.mergeAgentState({ taskProgress: 0.5 }); const result = await step.do("process", async () => { return processData(event.payload.data); }); await step.reportComplete(result); return result; } }

import { AgentWorkflow } from "agents/workflows"; import type { AgentWorkflowEvent, AgentWorkflowStep } from "agents/workflows"; export class ProcessingWorkflow extends AgentWorkflow<MyAgent, TaskParams> { async run(event: AgentWorkflowEvent<TaskParams>, step: AgentWorkflowStep) { // Call Agent methods via RPC await this.agent.updateStatus(event.payload.taskId, "processing"); // Non-durable: progress reporting to clients await this.reportProgress({ step: "process", percent: 0.5 }); this.broadcastToClients({ type: "update", taskId: event.payload.taskId }); // Durable via step: idempotent, won't repeat on retry await step.mergeAgentState({ taskProgress: 0.5 }); const result = await step.do("process", async () => { return processData(event.payload.data); }); await step.reportComplete(result); return result; } }

Start workflows from your Agent with runWorkflow() and handle lifecycle events:

export class MyAgent extends Agent { async startTask(taskId, data) { const instanceId = await this.runWorkflow("PROCESSING_WORKFLOW", { taskId, data, }); return { instanceId }; } async onWorkflowProgress(workflowName, instanceId, progress) { this.broadcast(JSON.stringify({ type: "progress", progress })); } async onWorkflowComplete(workflowName, instanceId, result) { console.log(`Workflow ${instanceId} completed`); } async onWorkflowError(workflowName, instanceId, error) { console.error(`Workflow ${instanceId} failed:`, error); } }

export class MyAgent extends Agent { async startTask(taskId: string, data: string) { const instanceId = await this.runWorkflow("PROCESSING_WORKFLOW", { taskId, data, }); return { instanceId }; } async onWorkflowProgress( workflowName: string, instanceId: string, progress: unknown, ) { this.broadcast(JSON.stringify({ type: "progress", progress })); } async onWorkflowComplete( workflowName: string, instanceId: string, result?: unknown, ) { console.log(`Workflow ${instanceId} completed`); } async onWorkflowError( workflowName: string, instanceId: string, error: unknown, ) { console.error(`Workflow ${instanceId} failed:`, error); } }

Key workflow methods on your Agent:

• runWorkflow(workflowName, params, options?) — Start a workflow with optional metadata
• getWorkflow(workflowId) / getWorkflows(criteria?) — Query workflows with cursor-based pagination
• approveWorkflow(workflowId) / rejectWorkflow(workflowId) — Human-in-the-loop approval flows
• pauseWorkflow(), resumeWorkflow(), terminateWorkflow() — Workflow control

Synchronous setState()

State updates are now synchronous with a new validateStateChange() validation hook:

export class MyAgent extends Agent { validateStateChange(oldState, newState) { // Return false to reject the change if (newState.count < 0) return false; // Return modified state to transform return { ...newState, lastUpdated: Date.now() }; } }

export class MyAgent extends Agent<Env, State> { validateStateChange(oldState: State, newState: State): State | false { // Return false to reject the change if (newState.count < 0) return false; // Return modified state to transform return { ...newState, lastUpdated: Date.now() }; } }

scheduleEvery() for recurring tasks

The new scheduleEvery() method enables fixed-interval recurring tasks with built-in overlap prevention:

// Run every 5 minutes await this.scheduleEvery("syncData", 5 * 60 * 1000, { source: "api" });

// Run every 5 minutes await this.scheduleEvery("syncData", 5 * 60 * 1000, { source: "api" });

Callable system improvements

• Client-side RPC timeout — Set timeouts on callable method invocations
• StreamingResponse.error(message) — Graceful stream error signaling
• getCallableMethods() — Introspection API for discovering callable methods
• Connection close handling — Pending calls are automatically rejected on disconnect

await agent.call("method", [args], { timeout: 5000, stream: { onChunk, onDone, onError }, });

await agent.call("method", [args], { timeout: 5000, stream: { onChunk, onDone, onError }, });

Email and routing enhancements

Secure email reply routing — Email replies are now secured with HMAC-SHA256 signed headers, preventing unauthorized routing of emails to agent instances.

Routing improvements:

• basePath option to bypass default URL construction for custom routing
• Server-sent identity — Agents send name and agent type on connect
• New onIdentity and onIdentityChange callbacks on the client

const agent = useAgent({ basePath: "user", onIdentity: (name, agentType) => console.log(`Connected to ${name}`), });

const agent = useAgent({ basePath: "user", onIdentity: (name, agentType) => console.log(`Connected to ${name}`), });

Upgrade

To update to the latest version:

npm i agents@latest

For the complete Workflows API reference and patterns, see Run Workflows.