How do I receive external webhooks and kick off a workflow?

To receive an external webhook and kick off a workflow, the usual pattern is:

1. Create an HTTP endpoint that external services can call.
2. Validate the request for authenticity and structure.
3. Translate the payload into a workflow trigger event.
4. Start the workflow asynchronously so the webhook responds quickly.

Typical flow

1) Expose a webhook URL

Set up an endpoint like:

POST /webhooks/provider-x

External systems send JSON to this URL.

2) Verify the request

Check one or more of:

• shared secret / HMAC signature
• API key/header token
• timestamp to prevent replay
• allowed IPs, if applicable

This is important before triggering anything.

3) Parse and normalize the payload

Convert the incoming event into your internal format, for example:

{
  "event_type": "order.created",
  "source": "stripe",
  "data": { ... }
}

4) Trigger the workflow

Depending on your stack, this could mean:

• enqueue a job
• publish to a message queue/topic
• call a workflow engine API
• dispatch an internal event

5) Return a fast response

Respond with 200 OK or 202 Accepted quickly so the webhook sender doesn’t time out.

---

Example architecture

Webhook provider → API endpoint → auth/validation → queue/event bus → workflow worker/orchestrator

This is preferred over running the workflow directly in the webhook request because it’s:

• more reliable
• easier to retry
• less prone to timeout
• safer under traffic spikes

---

Example in pseudocode

@app.post("/webhooks/provider-x")
def handle_webhook(request):
    verify_signature(request.headers, request.body)

    event = parse_payload(request.json)

    workflow_queue.enqueue({
        "workflow": "process_order",
        "payload": event
    })

    return {"status": "accepted"}, 202

---

If you’re using a workflow engine

Many workflow platforms support direct webhook triggers or an API to start runs:

• Temporal: start a workflow via API/service worker
• Airflow: trigger DAG runs
• Step Functions: start execution via AWS API
• n8n / Zapier / Make: webhook trigger nodes
• Prefect: trigger deployments/runs

---

Best practices

• Make webhook processing idempotent using event IDs.
• Store the raw payload for debugging/auditing.
• Retry failed workflow starts safely.
• Acknowledge the webhook before doing heavy work.
• Secure the endpoint with signatures or tokens.

If you tell me your stack (e.g. Node.js, Python, AWS, Temporal, Airflow, n8n, etc.), I can give you a concrete implementation example.