Security. Defense in depth.

Plooi leans on Postgres RLS, per-row encryption, strict secret handling, and server-side validation. No single layer is the wall — every layer is.

What protects what

• Row Level Security (RLS) on every table — auth.uid() = user_id enforced on SELECT, INSERT, UPDATE, DELETE, with a WITH CHECK on every mutation.
• BYOK key encryption — AES-256-GCM with a per-row salt and nonce, key material derived per-row via HKDF-SHA256 from a master key kept in Supabase Function secrets (a separate store from Postgres).
• Bcrypt hashing for public-link passwords.
• Security headers — CSP, HSTS, X-Frame-Options, referrer policy.
• Stripe webhook signing and atomic idempotency at the database layer.
• Audit logs for every admin action, key save/delete, and deletion request.
• Granular admin roles scoped by capability rather than blanket access.

How BYOK keys are stored

• Cipher: AES-256-GCM, per-row 16-byte salt + 12-byte nonce.
• Key derivation: HKDF-SHA256 against a master key held in Supabase Function secrets — not in Postgres, not in env vars shipped to the browser.
• Writes: browser → store-api-key edge function → encrypt → store. Plaintext exists for one network hop.
• Reads from the browser: only through the user_api_keys_public view, which projects id, service_name, key_hint (last four chars), and key_version. The ciphertext column is REVOKEd from authenticated entirely.
• Decrypts: only inside ai-proxy, in memory, for one provider call. Plaintext is discarded on response.
• Never written to application logs, audit logs, Sentry, analytics, or database backups.

Errors that bubble up from providers are sanitized server-side. Patterns like sk-ant-*, sk-proj-*, AIzaSy*, ?key=*, and Bearer * are stripped before they reach the browser, Sentry, or any log line.

See Bring your own key for the canonical version.

Secrets and keys

• Frontend variables only ever via VITE_* — these end up in the browser, so they cannot hold anything sensitive.
• Server-side secrets only via Supabase Secrets — Stripe webhook key, Service Role key, master encryption key, cron secrets.
• The Service Role key is never used in the frontend. If you find a reference, it’s a bug.

Ongoing practice

• MFA for admins (planned).
• Dependabot for dependency updates.
• Monitoring on unusual auth events and on the rate of store-api-key / delete-api-key calls per user.