Resend API Key Exposed
A Resend API key is public, letting anyone send email from your verified domain.
Why it matters
A Resend API key is public, letting anyone send email from your verified domain. Because the mail passes your own authentication records, phishing sent with this key is very hard for recipients to distinguish from your real email, and abuse can damage your domain's sending reputation.
How ShipReady detects it
Detects credentials that reached the browser. Scans the page HTML and every linked JavaScript bundle for the literal shapes real provider keys take — `sk_live_`, `AKIA`, `ghp_`, a JWT with a service_role claim — rather than guessing from entropy. High-entropy string detection finds build hashes, CSS class names and base64 images on almost every site; provider prefixes are unambiguous, which is why this check reports only what it can name. A match is evidence, not inference: the value was served to anyone who loaded the page. Evidence records the variable NAME and a ten-character prefix, never the key, because a report that quoted the secret would republish it. Bundles are fetched once per scan and shared across pages, so a key present in a chunk loaded on ten routes is reported once.
Detection is deterministic. ShipReady reports this only when it observes the condition directly, and prefers to miss a real problem over inventing one. Rule version 1.4.0.
How to fix it
This is the prompt ShipReady puts in your report — written to be pasted straight into Cursor, Claude Code, or whichever assistant built the app.
Revoke this key at resend.com/api-keys and issue a new one with sending-only permission. Send email from a server route handler or server action instead of the client. Then review your Resend logs for messages you did not send, since a leaked key allows mail from your verified domain.
Frequently asked questions
- What does "Resend API Key Exposed" mean?
- A Resend API key is public, letting anyone send email from your verified domain.
- How serious is it?
- ShipReady rates this critical. Fix before launch. On its own, this is enough to compromise the application.
- How do I fix it?
- Paste the fix prompt on this page into Cursor, Claude Code or your AI editor. It is the same prompt ShipReady puts in your report.
- Can I check my own site?
- Yes — ShipReady scans up to ten pages of any public site for free and reports this alongside every other check.
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