Product and documentation updates for SimZ clients

Use this changelog to track notable SimZ documentation and client-facing API updates.

June 16, 2026

June 16, 2026

Lead Receive credit preflight check

The Lead Receive Service now verifies the company’s available credit balance before creating or queueing a lead batch.

  • If the account has zero or negative credits, the request returns 402 Payment Required with code: "INSUFFICIENT_CREDITS". The batch is not created and no leads are queued. Add credits, then resubmit.
  • If the credit balance cannot be verified, the request fails closed and returns 503 Service Unavailable with code: "BILLING_CHECK_FAILED". No leads are queued — retry shortly.

See Errors and Rate Limits for the full response shapes and retry guidance.