OpenClaw Webhook Signature Fix

Webhook signature failures are annoying because the payload often looks perfectly fine. The sender says the signature is bad, your handler says the body is bad, and everybody swears the secret is correct. The usual issue is that the raw request changed before verification or the wrong secret is being used in one environment.

Confirm the failure mode

Before changing code, confirm that the failure is truly signature-related. Look for requests arriving, being rejected early, and failing consistently even though the sender claims delivery. Compare environment secrets and verify whether the framework is giving you the untouched raw body.

openclaw gateway status
# inspect webhook handler logs
# check env source for the exact shared secret in each environment

# safe debug fields to log
request_id
signature_header_present
secret_version
body_length

If the raw body is parsed and reserialized before verification, you already found a prime suspect. JSON equivalence is not enough. Signature checks care about the exact bytes.

It is worth taking an extra minute here because many so-called fixes are just symptom suppression. If you misclassify the failure, you often make the system quieter without making it healthier.

Usual root causes

• Using parsed JSON instead of the raw request body for verification.
• Mismatched secrets across local, staging, and production environments.
• Proxy or middleware layers rewriting the body or headers before your handler sees them.
• Copy-paste mistakes during secret rotation that leave old values in one service.

That list covers most real incidents. Signature bugs are usually boring plumbing bugs, not cryptography mysteries.

At this stage I try to narrow the issue to one primary failure path instead of chasing every plausible theory at once. Most operational fixes get easier the moment the team stops debugging five ghosts simultaneously.

A repair sequence that holds up

1. Read the raw body exactly as received and verify before any parsing or mutation.
2. Confirm the active secret in the sender and receiver environments matches the intended version.
3. Add narrow logging around verification result, secret version, and request identifiers, not full sensitive payload dumps.
4. Replay a known-good webhook safely and confirm the handler now verifies and continues down the normal path.

The goal is not just making the error disappear. The goal is making the verification path inspectable enough that the next failure is obvious faster.

After the repair, run one controlled verification pass. A fix is only real when you can reproduce the old failure safely and see the system behave differently for the right reason.

Prevention after the fix

• Document secret ownership and rotation steps in the workflow runbook.
• Keep verification tests around raw body handling so framework upgrades do not silently break them.
• Log enough metadata to distinguish signature failures from auth or timeout failures.
• Avoid unnecessary middleware on sensitive webhook paths.

That prevention step matters because webhook signature bugs love to come back during infrastructure changes.

The preventive step is where a repair becomes operational maturity instead of a one-time hero move. It is worth doing even when everyone is tempted to move on.

Even a short runbook note, test case, or alert tweak can save the next operator a lot of guesswork when the same pressure comes back later.

That tiny investment is usually cheaper than one more incident call, one more duplicate customer message, or one more late-night debugging session.

Once raw-body verification and secret handling are clean, these failures usually disappear for good, and the webhook path gets a lot easier to trust.

After that, leave a breadcrumb for the next operator. The best repair is the one the team can understand and repeat under pressure.

I would also note what normal looks like after the fix, not just what was broken before it. Recovery is easier when the team can recognize healthy behavior quickly.

If you want the runbooks, guardrails, and operator habits that keep these failures from bouncing back a week later, The OpenClaw Playbook is the practical version.