Outpay Production Checklist for USDC Checkout Integrations

Credentials and access

• API keys are stored in a secret manager and scoped minimally.
• Test and live credentials, merchants, wallets, databases, and webhooks are kept separate.
• Key rotation and revocation have been rehearsed.
• Dashboard and admin access are least-privilege and reviewed regularly.

Payment correctness

• The displayed recipient is the verified merchant payout wallet.
• Customer instructions state Base, native USDC, and the exact amount.
• The server fulfils only after a verified checkout.paid event or an operator-approved paid status.
• Pending, failed, expired, underpaid, and overpaid paths are all observable.
• Transaction hashes, checkout IDs, and request IDs are retained for reconciliation.

Webhooks and reliability

• Raw-body HMAC verification and timestamp validation are covered by tests.
• Delivery IDs and order transitions are unique and idempotent.
• Retries, manual retry, and endpoint disablement are monitored.
• HTTPS, rate limits, structured logs, alerting, and incident contacts are configured.

Beta gate

• The current payment-verification audit is closed by the responsible operator.
• Database backup and restore have been verified for the deployed environment.
• Known gaps in reorg handling and mismatch remediation have an accepted risk decision.
• The deployed API and webhook payload are pinned to a reviewed version.

Related documentation

• Deployment — the operator-facing release checklist.
• System status — the current capability and readiness matrix.
• Changelog — what changed since your last integration review.