Payroll API

Authentication

Every request except the health check carries an Authorization: Bearer header with an API key from the console:

mpk_test_7hqk2m9vslgp4wz3c1yxfb0e
mpk_live_9k2pqxlt5m0wnzvcb1y47rghf

Authorization: Bearer mpk_test_7hqk2m9vslgp4wz3c1yxfb0e

The test/live segment picks the environment. Sandbox keys are free and unrestricted — since this API has no side effects, there’s no simulator to configure and nothing to keep isolated beyond metering: sandbox usage is simply never billed. See Sandbox.

Multi-employer keys

Accounting firms and vendors running payroll for more than one employer company send X-Company-Id on every request; a key scoped to a single employer can omit it.

Rotating a key

Create a new key in the console before revoking the old one — both work simultaneously so you can roll a deploy without downtime, then revoke the old key once the new one is confirmed live.