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Everything that goes wrong with webhooks, and why
Five guides, written in the order the problems actually arrive: what a webhook is, how to verify the signature, what to do when the delivery log says it failed, how to survive duplicates, and when polling is the better choice after all.
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What is a webhook?
A webhook is an HTTP request a service sends you when something happens. What that means, how it differs from an API call, and what a working endpoint needs.
How to verify a webhook signature
Why HMAC signature verification fails and how to fix it: raw bytes, the signed string each provider builds, timing-safe comparison, and the timestamp window.
6 stepsDebugging webhook 400 and 401 errors
Your provider says the delivery failed. What 400, 401, 403, 404, 405, 415, 429, 500 and timeout responses each mean, and how to confirm the cause.
6 stepsWebhook retries and idempotency
Deliveries arrive twice, out of order, or after you gave up. How each provider retries, why exactly-once does not exist, and how to make a handler idempotent.
5 stepsWebhooks vs polling
When webhooks beat polling, when polling is the better engineering choice, and why most mature integrations end up running both.
Also here
When you would rather try it than read it
Provider guides
What Stripe, GitHub, Shopify, Razorpay and eleven others actually send — the real headers, the real payload, and the failure modes specific to each.
Signature verifier
Paste a raw body, a signature header and a secret, and see the signed string that gets built and the digest it produces. Runs entirely in your browser.
One click
Get a URL and send it something.
No account, no email, no limit on how many you create. The URL is live the moment it exists.
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