Fix guide · critical · klaviyo_private_key

Klaviyo API key in your client bundle

Why it matters

Read/write your Klaviyo lists, subscriber data, campaigns, flows. Automated scrapers harvest these keys from public bundles within hours; assume the key is compromised the moment it shipped.

How to fix it

1. Revoke the key immediately at https://www.klaviyo.com/account#api-keys-tab.
2. Move the new key to server-only env vars. Never use a name with the NEXT_PUBLIC_, VITE_, or PUBLIC_ prefix.
3. Pattern your calls as client → your API → Klaviyo. Never client → Klaviyo directly.
4. Set a spend or rate limit in the Klaviyo console as a safety net.
5. Add a CI gate to fail any future deploy that includes the key pattern: vibecheck https://your-deploy.com --exit-on critical.

Did vibecheck flag this on your app?

If you reached this page from a vibecheck inspection report, the redacted match in your scan output is the exact string we found in your bundle. After applying the fix above, run the inspection again — the finding should clear.