You can suspend/resume workflows in playground

Mastra workflows have suspend/resume functionality enabling to wait for humans in the loop. That works in playground now!

Here’s a demo:

We also shipped an API for automatically closing streams when a workflow suspends, allowing them to be resumed later

resumeStream

The default behavior of suspend() is to leave the stream open. We shipped a closeOnSuspend option to close a stream automatically when a workflow suspends.

Now, when you’re ready to resume, use resumeStream to pick up your stream exactly where the workflow left off.

As an example:

 1// 1. Initial execution with closeOnSuspend enabled
 2const run = await workflow.createRunAsync();
 3const output = run.stream({
 4  inputData: { task: 'approval_needed' },
 5  closeOnSuspend: true, // 🔑 Stream will close when workflow suspends
 6});
 7
 8// Stream events until suspension
 9for await (const chunk of stream.fullStream) {
10  console.log(chunk.type, chunk.payload);
11  // Stream automatically closes when workflow suspends
12}
13
14const result = await stream.result;
15console.log(result.status); // 'suspended'
16
17// --- Time passes, user provides input ---
18
19// 2. Resume and get a NEW stream for the continuation
20const resumedOutput = await run.resumeStream({
21  resumeData: { userInput: 'approved' },
22  step: 'approval-step', // Optional - auto-detected if omitted
23});
24
25// Stream remaining events from the new stream
26for await (const chunk of resumedStream.fullStream) {
27  console.log('Resumed:', chunk.type, chunk.payload);
28}
29
30const finalResult = await resumedStream.result;
31console.log(finalResult.status); // 'success' or 'failed'

We hope this helps you build more human-in-the-loop workflows in Mastra. Happy building! 🚀