Idempotency key is also sent in JSON payloads

[saxon134]

VideosResource.create and TasksResource.create build the JSON body from the full params mapping while also converting params.get("idempotency_key") into the Idempotency-Key header. A call such as client.videos.create(model="m", prompt="p", idempotency_key="idem") sends both the header and a body field named idempotency_key. Since this is an SDK transport option, it should be removed from the request payload before calling _payload; otherwise APIs may reject the unexpected field or treat it as model input.

File: src/globalrouter/_resources.py

Line: 335

Severity: medium

Summary: idempotency key leaks into create payloads

[saxon134]

Coding Loop Plan

Refined Issue

VideosResource.create/create_async and TasksResource.create/create_async currently use idempotency_key both as an Idempotency-Key header source and as part of the JSON request payload. Treat idempotency_key as an SDK transport option for these create calls and exclude it from json_body while preserving the header behavior.

Implementation Plan

Implementation Plan

Limit the change to src/globalrouter/_resources.py and targeted request-shape regression tests. Add a small, non-mutating way to remove idempotency_key from the params passed to _payload for the create methods that send an Idempotency-Key header. Then add tests that inspect the actual outgoing JSON for both videos and tasks so the transport option cannot leak into request bodies again.

Development Tasks

1. Strip idempotency_key from create payload params
   In src/globalrouter/_resources.py, update VideosResource.create, VideosResource.create_async, TasksResource.create, and TasksResource.create_async so idempotency_key is still read from params for _idempotency_header(...) but is not included in the mapping passed to _payload. Use a small non-mutating helper or local filtered mapping; do not mutate params, do not change _payload behavior globally, and do not affect batch/list/get/update methods.
   Files: src/globalrouter/_resources.py
   Tests: python -m pytest tests/test_client.py -q

2. Add regression coverage for idempotency payload leak
   Extend tests/test_client.py so the mock transport asserts that video and task create requests include the Idempotency-Key header but their JSON bodies do not contain idempotency_key. Cover both /api/v1/videos and /v1/tasks create paths. Keep the tests focused on request shape and existing response handling.
   Files: tests/test_client.py
   Tests: python -m pytest tests/test_client.py -q, python -m pytest -q