Bad Gateway (502)

Only the sandbox simulators return it, all seven of them under /sandbox/simulate/: the simulated provider notice did not reach Roster's webhook receiver in time. The detail reads webhook edge unreachable — retry later. This is a failure on our side, not a problem with your request.

A 502 does not prove that nothing happened: the notice can reach Roster after the simulator stopped waiting for it.

What to do

• Wait a moment, then read the state before you send the simulation again: GET /v1/enrollments/{id} for a payroll or identity simulation, and GET /v1/financial_events for a deposit, a returned transfer or an account closure.
• A deposit (/sandbox/simulate/deposit): the simulated bank may already hold the credit. Retry later with the same Idempotency-Key and body: the retry resends the same notice and never credits twice.
• A payroll or identity simulation whose notice did arrive can refuse the retry: once the enrollment moved on, or the identity outcome is recorded, the retry answers 400 naming what it found. Treat that as done.
• If it keeps failing, contact support with the request_id.