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Overview

Instead of polling GET /jobs/{id} repeatedly, you can provide a webhook URL to receive a POST request when your job completes. This is more efficient and reduces unnecessary API calls.

Using Webhooks

Add the X-Webhook-URL header to any generation request. When the job reaches a terminal state (completed, failed, or cancelled), the API will send a POST request to your URL with the full job data.
// npm install @krea-ai/sdk
import { Krea } from "@krea-ai/sdk";

const krea = new Krea({ apiKey: process.env.KREA_API_KEY });

const job = await krea.image(
  "bfl/flux-1-dev",
  {
    prompt: "a serene mountain landscape at sunset",
    width: 1024,
    height: 576
  },
  { webhookUrl: "https://your-server.com/webhook" }
);

console.log(`Job ID: ${job.job_id}`);
// Your webhook will receive the results when complete

Webhook Payload

When the job completes, your webhook URL receives a POST request with the job data:
{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "completed",
  "created_at": "2025-01-15T10:30:00.000Z",
  "completed_at": "2025-01-15T10:30:05.000Z",
  "result": {
    "urls": ["https://..."]
  }
}

Best Practices

Respond quickly - Return a 2xx status code promptly. Process the webhook data asynchronously if needed.
Validate the payload - Verify the job_id matches a job you initiated before processing results.
  • Use HTTPS endpoints for security
  • Implement idempotency in case of duplicate deliveries
  • Log webhook receipts for debugging

Webhooks vs Polling

ApproachProsCons
WebhooksReal-time notifications, fewer API callsRequires a public endpoint
PollingWorks anywhere, no server neededMore API calls, slight delay
Use webhooks when you have a server that can receive HTTP requests. Use polling for client-side applications or when you can’t expose a public endpoint.

Next Steps

Job Lifecycle

Learn about job states and status polling

Code Examples

See complete examples with webhook handling