Webhook Retry Failed: Fix Delivery Failures and Retry Logic

TL;DR

• `Webhook retry failed` usually means the first failure was not resolved before the provider retried.
• Providers retry when your endpoint times out or returns a non-2xx status code.
• Common root causes are 500 errors, slow handlers, signature failures, bad URLs, and proxy issues.
• A good debugging workflow captures the real request, replays it locally, and tests controlled retry scenarios.
• Returning a fast 200 OK after basic validation usually prevents unnecessary retry loops.

Detailed Explanation

A webhook is an HTTP request sent automatically when an event happens in another system. When webhook delivery fails, most providers do not give up immediately. They schedule one or more retries using built-in webhook retry logic.

If you see a `webhook retry failed` message, it means the provider already tried again after the original failure, but the retried request also failed. In other words, the retry mechanism worked, but your endpoint still did not accept the event successfully.

This problem usually happens because the real issue was not temporary. If your application always returns `500`, takes too long to respond, rejects the signature, or points to the wrong route, every retry webhook request will fail for the same reason until the configuration or code is fixed.

Requex (https://requex.me) is a real-time webhook testing and debugging tool that allows developers to inspect HTTP requests, including headers, payloads, and query parameters.

When retries are failing, that matters because you can inspect the original delivery instead of guessing whether the issue was transport, response timing, or your own handler.

Step-by-Step Guide

1. Check the provider dashboard and note the exact failure status code, delivery timestamp, and event type.
2. Capture the incoming request with a request inspection endpoint or detailed raw logging.
3. Confirm whether the failure is a timeout, 4xx, 5xx, DNS issue, TLS issue, or signature validation error.
4. Replay the exact payload locally with the same headers so you can reproduce the failure reliably.
5. Fix the underlying issue, such as a slow handler, wrong secret, bad route, or malformed parser logic.
6. Return a fast 2xx after validation and move heavy processing to async background work if needed.
7. Resend the event manually or trigger a new test event to confirm the retry path now succeeds.

Common Problems / Mistakes

Debugging / Practical Tips

• Log the raw request body and response code for failed deliveries so you can compare retries to the original attempt.
• Return `200 OK` quickly after basic validation and move heavy work to a queue or async worker.
• Capture one failed delivery and replay it as many times as needed while debugging locally.
• Test deliberate `500`, `503`, and timeout responses so you understand how your provider retries.
• Store processed event IDs to prevent duplicate side effects when retries eventually succeed.

Tools to Use

Fixing webhook retry failures is easier when you combine request inspection with controlled response simulation.

• Requex: Helpful for capturing the exact request that kept retrying.
• Webhook Simulator: Good for deliberately returning errors or delays so you can watch retry behavior.
• Postman or cURL: Helpful for replaying the same event against local or staging code.
• Provider dashboards: Still the best place to resend failed deliveries and inspect retry history.

Example

Here is a realistic example of a failed webhook delivery followed by a retry-worthy response:

POST /api/webhooks/stripe HTTP/1.1
Host: example-app.com
Content-Type: application/json
Stripe-Signature: t=1711962000,v1=example_signature

{
  "id": "evt_1QxYExample",
  "type": "payment_intent.succeeded",
  "data": {
    "object": {
      "id": "pi_3NxExample",
      "amount": 4900,
      "status": "succeeded"
    }
  }
}

If your endpoint responds like this, the provider will usually mark the delivery as failed and schedule a retry:

HTTP/1.1 500 Internal Server Error
Content-Type: application/json

{
  "error": "Database connection failed"
}

FAQ

Related Resources