Line-oriented upstream executors can emit `event:` and `data:` as
separate chunks, but the Responses handler had started terminating
each incoming chunk as a full SSE event. That split `response.created`
into an empty event plus a later data block, which broke downstream
clients like OpenClaw.
This keeps the fix in the handler layer: a small stateful framer now
buffers standalone `event:` lines until the matching `data:` arrives,
preserves already-framed events, and ignores delimiter-only leftovers.
The regression suite now covers split event/data framing, full-event
passthrough, terminal errors, and the bootstrap path that forwards
line-oriented openai-response streams from non-Codex executors too.
Constraint: Keep the fix localized to Responses handler framing instead of patching every executor
Rejected: Revert to v6.9.7 chunk writing | would reintroduce data-only framing regressions
Rejected: Patch each line-oriented executor separately | duplicates fragile SSE assembly logic
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Do not assume incoming Responses stream chunks are already complete SSE events; preserve handler-layer reassembly for split `event:`/`data:` inputs
Tested: /tmp/go1.26.1/go/bin/go test ./sdk/api/handlers/openai -count=1
Tested: /tmp/go1.26.1/go/bin/go test ./sdk/api/handlers -count=1
Tested: /tmp/go1.26.1/go test ./sdk/api/handlers/... -count=1
Tested: /tmp/go1.26.1/go/bin/go vet ./sdk/api/handlers/...
Tested: Temporary patched server on 127.0.0.1:18317 -> /v1/models 200, /v1/responses non-stream 200, /v1/responses stream emitted combined `event:` + `data:` frames
Not-tested: Full repository test suite outside sdk/api/handlers packages
Guard the openai-response streaming path against truncated/invalid SSE data payloads by validating data: JSON before forwarding; surface a 502 terminal error instead of letting clients crash with JSON parse errors.
- Introduced `passthrough-headers` option in configuration to control forwarding of upstream response headers.
- Updated handlers to respect the passthrough headers setting.
- Added tests to verify behavior when passthrough is enabled or disabled.
- Introduced unit tests for request logging middleware to enhance coverage.
- Added WebSocket-based Codex executor to support Responses API upgrade.
- Updated middleware logic to selectively capture request bodies for memory efficiency.
- Enhanced Codex configuration handling with new WebSocket attributes.
Introduce `TestExecuteStreamWithAuthManager_DoesNotRetryAfterFirstByte` to validate that stream executions do not retry after receiving partial responses. Implement `payloadThenErrorStreamExecutor` for test coverage of this behavior.
zilianpn