Security

Protect keys, verify webhooks, and keep reputation healthy with account gates and Planet-managed limits.

API key rotation

Create a new key, update clients, then revoke the old key. Keys are stored hashed — plaintext is shown once at creation.

Scoped keys

emails:send — single and batch send
emails:read — retrieve message status
domains:read — list domains
webhooks:write — manage endpoints

IP allowlists

Optionally restrict API key usage to known egress IPs. Mobile clients should never use allowlisted live keys directly — proxy through your backend.

HMAC webhook verification

Always verify X-PSend-Signature (or Svix-compatible headers) before acting on events. Reject stale timestamps to prevent replay.

Rate limiting

Throughput caps are managed in Planet per account and pool. Exceeding them returns 429 with a Retry-After header. Bulk batch endpoints share the same budget as single sends.

Account gate thresholds

Bounce rate above 5% — progressive throttle, then hold for review
Complaint rate above 0.1% — immediate send pause until resolved

The gate protects shared and dedicated IP pools so one bad list cannot burn deliverability for everyone.

TLS

All API and webhook traffic requires TLS 1.2+. Plain HTTP is rejected.