> ## Documentation Index > Fetch the complete documentation index at: https://docs.uselamina.ai/llms.txt > Use this file to discover all available pages before exploring further. # Handle Long-Running Executions > Recommended patterns for apps that take minutes to complete, especially image-heavy and video-heavy workflows. ## Why Lamina Uses Async Jobs Some Lamina apps complete in seconds. Others, especially multi-step image/video pipelines, may take much longer. Because of that, `POST /v1/apps/{appId}/runs` starts work and returns an execution handle immediately instead of blocking until the final output is ready. If you are integrating Lamina into a backend, queue system, merchant tool, or content platform, design around the execution lifecycle from the start. ## Two Delivery Patterns ### Option 1: Webhook (Recommended) Pass a webhook URL as a query parameter. When the execution completes, we POST the results to your URL. ```bash theme={null} POST /v1/apps/{appId}/runs?webhook=https://your-server.com/callback ``` Benefits: * No polling loop needed * Results arrive as soon as they're ready * Signed with ED25519 for security * Automatic retries (3 attempts with backoff) ### Option 2: Polling Poll `GET /v1/runs/{runId}` on an interval until `status` reaches `completed` or `failed`. Use different polling intervals depending on the workflow: * Short image jobs: every 3-5 seconds * Heavier multi-step jobs: every 5-10 seconds * Long-running video jobs: every 10-15 seconds Avoid polling every second in production. ## Recommended Backend Flow Call `POST /v1/apps/{appId}/runs?webhook=` and store the returned run ID. Save it in your job table, queue, or request state so you can resume later. Your webhook endpoint receives the completed results, or poll `GET /v1/runs/{runId}` as a fallback. ## What To Persist For every execution you start, store at least: * `runId` * `appId` * input payload * current status * started timestamp This makes retries, dashboards, and support much easier. ## Failure Handling If an execution fails: * inspect the top-level `errorMessage` * inspect each output's `error` * keep the original inputs for debugging or replay If your product has end users, show a user-friendly status while keeping the raw error for logs and support tooling. ## Webhook Verification When receiving webhook callbacks, verify the signature to ensure it's from Lamina: 1. Fetch the public key from `GET /v1/webhooks/signing-key` 2. Verify the ED25519 signature: `verify(signature, ".", publicKey)` 3. Reject timestamps older than 5 minutes (replay protection) See the [Webhook Signing Key](/api-reference/get-webhook-signing-key) reference for verification code examples.