Impersonation (X-On-Behalf-Of)

[derpixler]

API Reference: On Behalf Of

Two modes for API-level impersonation.

Block-based (preferred): $client->performOnBehalfOf($userId, fn() => ...) sets the X-On-Behalf-Of header before the callback and clears it in a finally block — guaranteed cleanup even if the callback throws. Use for single or batched operations where impersonation should be temporary.

Persistent: $client->setOnBehalfOfUser($id) sets the header globally — all subsequent requests carry it until unsetOnBehalfOfUser() is called. Use when an entire process runs as a specific user.

The header is injected by RequestHandler — if onBehalfOfUser is set, every request() call adds the header before sending.

Acceptance Criteria

• Testing: ZammadClientTest — performOnBehalfOf() sets X-On-Behalf-Of header during callback, clears header in finally (even on exception)
• Documentation in README: README — $client->performOnBehalfOf($id, fn) example

Depends on

• connect() Factory #117
• RequestHandler + Exception Mapping #87

Produces

• ZammadClient (onBehalfOf methods)
• RequestHandler (header injection)