The First Hour After a Suspected API Key Compromise

The moment a credential is suspected of being compromised, revoke it immediately, before you've fully confirmed the suspicion. The cost of a false alarm, a legitimate integration briefly disrupted while you reissue a credential, is far smaller than the cost of leaving a genuinely compromised credential active while you investigate.

Have the revocation mechanism ready before you need it: know exactly which button to click or which command to run, tested in advance, not something to figure out for the first time during the incident itself. Assign this step to a specific on-call role, not "whoever notices first," since an incident discovered at an odd hour needs a clear owner who can act immediately rather than a diffusion of responsibility that delays the one step that matters most in the first few minutes of the whole response.

Once the immediate credential is revoked, check what else that identity had access to and whether any of it shows signs of misuse: unusual data access patterns, actions outside the caller's normal behavior, requests from unfamiliar locations. Contain anything showing active misuse, additional key revocations, session invalidation, before moving to the slower work of figuring out how the credential was exposed in the first place.

Resist the urge to fully root-cause before containing. It's tempting to understand the whole story first, but containment is time-sensitive in a way root-causing generally isn't, and a partial containment done quickly beats a complete, well-understood response that arrives after more damage has already happened.

For example, suppose a contractor's API key shows up in a public code repository at an odd hour. The on-call owner revokes it within minutes, before anyone has confirmed whether it was used. A teammate then reviews that key's recent activity while a third person drafts the initial customer notice from the template. Nothing here requires knowing the root cause yet. Each person has one job, and the order matters more than the detail. The common mistake is letting the discussion turn into a debate about how the key leaked, which delays the one action that limits damage. If you catch yourself asking why before the key is revoked, stop and revoke.

Decide in advance who needs to know and how fast: engineering leadership immediately, affected customers or partners within a defined window if their data or access was involved, and legal counsel early if there's any chance of a regulatory notification obligation. Waiting to notify until you have a complete picture usually means notifying too late.

A short, honest initial notice, here's what we know, here's what we're doing, more details to follow, is better than delaying notification until every detail is confirmed. Keep a template for this initial notice drafted in advance, since writing careful, accurate communication under time pressure during a real incident is exactly when mistakes in tone or unintentionally overstated claims creep in, and having a starting point to edit is faster than composing something from scratch while the rest of the response is still underway.

A postmortem that only identifies the technical root cause, a key committed to a public repo, a credential left in an old config file, misses the second question: why did detection take as long as it did, and did the runbook actually work as written. Both questions matter equally for reducing the next incident's impact.

Update the runbook itself based on what the postmortem finds. A runbook that never changes after an incident either means it was already perfect, which is unlikely, or that the postmortem's findings aren't feeding back into the process that's supposed to use them. Schedule the runbook update as a specific task with an owner and a deadline coming out of the postmortem meeting, rather than a general action item that tends to quietly drop off everyone's list once the immediate pressure of the incident has passed.

The first-hour sequence, in order:

1. Revoke the suspect credential immediately, before the suspicion is confirmed, using a revocation step that a named on-call owner has already tested.
2. Check what else that identity could reach, and contain any sign of misuse with further key revocations or session invalidation before you root-cause.
3. Tell engineering leadership right away, send affected customers a short honest initial notice within your defined window, and involve legal counsel early if a regulatory duty is possible.
4. Hold a postmortem that asks both how the credential was exposed and why detection took as long as it did.
5. Turn the findings into a runbook update with a named owner and a deadline.