sk-proj- keys in client code — scoped, billable, harvestable
Scoping limits damage; publication removes it. If sk-proj- appears in served JS, rotate within minutes. Free scan confirms.
OpenAI’s modern keys scope to projects — good containment design that changes nothing about what publication costs you.
What an OpenAI project API key is
sk-proj- keys authenticate to one project’s resources: models, assistants, files within its limits.
sk-proj-FAKE000000000000000000000000The prefix is the claim: scanners and attackers alike identify the format before they know anything else about it, which is why recognition starts at the first characters rather than the last.
What it grants
Within project boundaries:
- Model inference billed to the org.
- Assistant/file stores where configured.
How it ends up in a bundle
Three arrival routes cover nearly every case we see:
- Chat features generated client-first by agents/builders.
- Demo components copied into production shells.
Does it belong in a browser?
Server-only; OpenAI offers no browser-restricted key class — proxies are the supported pattern.
Rotate it
platform.openai.com/api-keys → revoke → issue replacement inside same project → update server env.
Find it in seconds
Open DevTools on the deployed site and search the built assets for sk-proj-. If the search hits, the credential shipped; if it does not, check the chunks loaded on authenticated or interactive views, not just the landing page — the calling code often sits behind a route.
Manual searching proves one page on one day. KeyDrift fetches the deployment the way a browser would, follows chunks named only in route manifests, reads streamed hydration payloads, and classifies what it finds — secret, or public-by-design — so an anon key never shows up dressed as an emergency.
Make sure it stays gone
One more thing worth knowing before you close the tab: fixing this once does not end the story. Agents imitate whatever pattern is already in the repo, templates carry their own defaults, and the next feature request can reintroduce the same shape of code. Continuous monitoring re-scans every deploy and alerts only on change — new, regressed, resolved — so the comeback attempt is a notification instead of a quarter-end surprise.
The bigger picture
Zoom out and the pattern is bigger than one repo. AI-assisted output has outgrown review capacity everywhere at once, which means thousands of teams are making the same reasonable-looking tradeoffs in the same week. Nobody using modern tooling is uniquely exposed. The failure mode documented above is the modal outcome of velocity without verification, not evidence of carelessness.
How KeyDrift reports this exact finding
Report anatomy matters during incidents, so it is worth reading once calmly: masked string (never the live value — it ceases to exist outside the detection engine), salted fingerprint (trackable within your workspace, useless to strangers), chunk path (your starting point for a "git log -S" hunt), disposition (secret versus public-by-design), confidence (matches below 0.5 never reach the page at all).
Manual check, step by step
The full manual drill, for readers who want zero dependence on any tool: open the deployed site in a private window; launch DevTools → Sources; use Search-all-files (Ctrl/Cmd+Shift+F) for sk-proj-; then repeat for the other marker families — eyJ, sk_live_, sk-proj-, AKIA, postgres, BEGIN PRIVATE KEY. Decode anything JWT-shaped before reacting, and classify public-by-design formats as expected guests rather than intruders.
Close the loop with monitoring
If you take one operational step from this page, make it this: put the URL under continuous monitoring (free tier covers one project daily). The first scan tells you whether you have a problem today; the schedule tells you whether the problem comes back next month after someone re-adds the convenient line.
Common questions
Spend caps enough protection?
Caps bound damage post-publication; they do not prevent abuse or rate-limit exhaustion. Both, please.
Multiple keys found — same rotation?
Rotate each; audit created-keys lists for surprises (admin variant risk).
Run a free scan at keydrift.dev/scan — paste a URL or the bundle source itself, no account. Findings arrive masked, with the exact chunk they live in.