Justin Beckwith ed0cc1a4ab Serialize Responses routing fields before large inputs (#49675) ...

## Why

Gateways that inspect request bodies incrementally need routing fields before potentially multi-megabyte prompts so they can route requests without buffering the input first.

## What changed

Serialize `model`, `stream`, and optional `service_tier` before `input` in both HTTP Responses requests and WebSocket `response.create` messages. Preserve field values and omission of unset `service_tier`.

## Testing

Add an HTTP regression test with a 2 MiB input that checks routing field order and unchanged JSON contents. Extend WebSocket serialization coverage to assert the routing fields appear first, and check that HTTP requests omit unset `service_tier`.

GitOrigin-RevId: dbc174e1fe7ca30d0c00f075bc37dd5f97b27b37

2026-09-30 16:57:01 +00:00

..

clients.rs

Serialize Responses routing fields before large inputs (#49675)

2026-09-30 16:57:01 +00:00

models_integration.rs

Support explicit provider model catalog URLs (#46561)

2026-09-19 01:36:53 +00:00

realtime_websocket_e2e.rs

Enforce network policy throughout HTTP and WebSocket requests (#47389)

2026-09-22 23:37:39 +00:00

realtime_websocket_tls.rs

Honor configured proxies for realtime WebSocket connections (#47101)

2026-09-21 20:05:21 +00:00

sse_end_to_end.rs

Preserve raw response usage metadata (#41980)

2026-09-01 05:17:11 +00:00