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.