Async & Polling

┌──────────────┐                         ┌──────────────┐
│  AI client   │                         │  MCP server  │
└──────┬───────┘                         └──────┬───────┘
       │                                        │
       │── generate(tool, input) ─────────────▶│
       │                                        │  enqueue job
       │◀── { job_id, status: "pending" } ─────│  (returns in ~1s)
       │                                        │
       │── check_generation(job_id) ──────────▶│
       │◀── { status: "processing", done:false} │
       │                                        │
       │      ...wait poll_after_seconds...     │
       │                                        │
       │── check_generation(job_id) ──────────▶│
       │◀── { status: "success", output, done:true }
       │                                        │

{
  "job_id": "...",
  "status": "pending",
  "eta_seconds": 120,
  "poll_after_seconds": 10
}

const { job_id, poll_after_seconds } = await mcp.call('generate', { tool, input });

let result = { done: false };
let interval = poll_after_seconds;

while (!result.done) {
  await sleep(interval * 1000);
  result = await mcp.call('check_generation', { generation_id: job_id });
  interval = result.poll_after_seconds ?? interval;
}

if (result.status === 'success') {
  console.log(result.output);
} else {
  console.error(result.error);
}