Debug the failed webhook signature

About Signature Forensics

Signature Forensics shows you a realistic webhook scenario — body, headers, secret, and provider — and asks you to identify why HMAC signature verification keeps failing. Every day everyone gets the same challenge so you can compare results. Topics include Stripe, GitHub, Slack, Shopify, and generic HMAC webhooks.

Why it helps

• Build intuition for the most common webhook verification failure modes before a real incident.
• Learn why the raw body must be captured before any middleware parses or re-serializes it.
• Understand timestamp tolerance, encoding differences, and secret whitespace pitfalls.
• Use the related Webhook Signature Verifier to test signatures interactively.

Runs locally in your browser. Progress is stored only in this browser.

What this challenge teaches

Debug the failed webhook signature is a short drill for webhook signature debugging. A webhook signature check failed and you need to identify whether the timestamp, raw body, algorithm, encoding, or shared secret is wrong.

Example reasoning path

• Read the prompt and identify the artifact type before looking at the answer choices.
• Compare the expected target with each candidate result and eliminate options that are only formatting changes.
• Signature verification usually requires the exact raw body bytes; re-serializing JSON can change the signed payload.

After you solve it

Open Webhook Signature Verifier to apply the same skill to your own data. For a broader practice loop, return to Skill Challenges or open Workflow Gallery when the task needs multiple tools.

Challenge state stays local to this browser. Do not paste production secrets into practice prompts.

Practice notes for real projects

Use this page as a warm-up before touching real project data. Read the prompt, write down the signal you are looking for, and only then compare answer choices. That habit carries over to production debugging, where the first visible error is often a symptom rather than the root cause.

After the challenge, recreate the same pattern in the linked tool with a harmless sample. For example, replace real tokens, user identifiers, hostnames, and request bodies with safe values, then verify that the same reasoning still works. This keeps practice useful without exposing private data.

• Save time by checking the smallest artifact that reproduces the issue.
• Write one sentence explaining why the wrong answers fail; that explanation is the skill to reuse later.
• If the challenge involves security, treat decoded or inspected data as untrusted until a separate verification step confirms it.