fix(realtime): drop OpenAI-Beta header rejected by GA Realtime API

[key4ng]

Description

Problem

After #1504 bumped the realtime test to the GA model alias gpt-realtime, the openai-realtime job is still failing on main with the same 1005 (no status received) / ConnectionResetError pattern (run 26212745181).

Direct upstream reproduction (forcing HTTP/1.1 so the WS upgrade isn't masked by HTTP/2 framing) shows what's actually happening:

HTTP/1.1 101 Switching Protocols
…
{"type":"error","error":{
  "type":"invalid_request_error",
  "code":"beta_api_shape_disabled",
  "message":"The Realtime Beta API is no longer supported. Please use /v1/realtime for the GA API."
}}

OpenAI accepts the WebSocket upgrade (HTTP 101), then immediately sends an error event and closes the connection because the request carries OpenAI-Beta: realtime=v1. SMG forwards that error frame, the upstream tears down, the upgrade closure ends, and the already-upgraded client socket gets dropped → client sees 1005 / TCP RST.

Repeating the same handshake without the beta header succeeds and returns a proper GA session.created:

{"type":"session.created","session":{"id":"sess_…","model":"gpt-realtime","object":"realtime.session", …}}

So bumping the model in #1504 was necessary (the old preview snapshot 404s) but not sufficient (SMG's hardcoded beta header still triggers GA-shape rejection).

Solution

Drop the hardcoded OpenAI-Beta: realtime=v1 header from SMG's upstream WebSocket request. The GA Realtime API doesn't want it; the beta API that did want it has been retired.

Changes

• model_gateway/src/routers/openai/realtime/proxy.rs — remove the .insert("OpenAI-Beta", "realtime=v1") on the upstream tokio_tungstenite request. Leave a short comment documenting why, so nobody re-adds it.
• e2e_test/realtime/test_realtime_ws.py — drop OpenAI-Beta from the test's ws_headers fixture for cleanliness (the test sends it client→SMG, but SMG never proxies client headers upstream, so it was already inert).

Test Plan

• CI openai-realtime job goes green.
• Before/after: the 10 previously-failing tests pass; the 2 always-passing tests (test_missing_model_returns_error, test_missing_auth_returns_error) remain passing.

Direct verification with the upstream (already done locally):

• With OpenAI-Beta: realtime=v1 → code: beta_api_shape_disabled, then close.
• Without it → session.created frame with the full GA session object (model gpt-realtime, output_modalities ["audio"], server_vad turn detection, etc.).

Checklist

• cargo +nightly fmt --all -- --check passes
• cargo check -p smg passes
• cargo clippy --all-targets --all-features -- -D warnings (relying on CI)
• (Optional) Documentation updated
• (Optional) Please join us on Slack #sig-smg to discuss, review, and merge PRs

Summary by CodeRabbit

• Bug Fixes

  • Removed the incompatible realtime header from WebSocket requests and fixtures to ensure compatibility with GA Realtime endpoints.

• Tests

  • Updated end-to-end realtime WebSocket tests to match revised event and payload schemas: streaming now uses response.output_text.delta, session and response use output_modalities/text typing, response.done requires output_text content.type, conversation.item.added replaces conversation.item.created, and related assertions/logging adjusted.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 2049644c-2ba0-4698-a225-66057d209a0f

📥 Commits

Reviewing files that changed from the base of the PR and between 5694628 and cab68e7.

📒 Files selected for processing (2)

• e2e_test/realtime/test_realtime_ws.py
• model_gateway/src/routers/openai/realtime/proxy.rs

---

📝 Walkthrough

Walkthrough

The upstream WebSocket proxy no longer sends the OpenAI-Beta: realtime=v1 header. E2E realtime tests are updated to the GA event/payload schema: output_modalities, response.output_text.delta, session.audio.*, and content.type == "output_text" are validated across session, response, streaming, and cancellation flows.

Changes

Realtime WebSocket tests & proxy updates

Layer / File(s)	Summary
Remove OpenAI-Beta header from proxy and test fixture model_gateway/src/routers/openai/realtime/proxy.rs, e2e_test/realtime/test_realtime_ws.py	Proxy upstream request and test fixture both remove the OpenAI-Beta: realtime=v1 header; only the Authorization bearer token is forwarded to upstream.
Session setup and schema assertions e2e_test/realtime/test_realtime_ws.py	Session setup messages use type: "realtime" and output_modalities: ["text"]; session.created/session.updated assertions validate session.audio.input and session.audio.output fields and expect output_modalities.
response.create and response.done checks e2e_test/realtime/test_realtime_ws.py	All response.create payloads use output_modalities; response.done assertions expect output content items with content.type == "output_text".
Streaming deltas and cancellation sync e2e_test/realtime/test_realtime_ws.py	Streaming collection and schema validation now target response.output_text.delta; tests wait for deltas to start streaming before issuing response.cancel and assert delta counts and logs for the new delta type.
Multi-turn conversation event update e2e_test/realtime/test_realtime_ws.py	Multi-turn conversation test uses response.create with output_modalities and now asserts conversation.item.added events instead of conversation.item.created.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• lightseekorg/smg#660: Both PRs are centered on the Realtime WebSocket E2E test/proxy behavior—main PR adjusts e2e_test/realtime/test_realtime_ws.py to the GA WebSocket event/payload schema and removes the OpenAI-Beta: realtime=v1 header in proxy.rs, aligning with the integration test added in PR #660.
• lightseekorg/smg#725: The main PR changes the websocket proxy behavior by removing the OpenAI-Beta: realtime=v1 header inside proxy::run_ws_proxy, while the retrieved PR refactors the WS handler to wrap that proxy call and record worker outcomes—both touch the realtime WS proxy execution path.

Suggested reviewers

• slin1237
• XinyueZhang369

Poem

🐰 I hopped through headers, clipped the trace,
Deltas now dance in a GA-shaped place.
Sessions sing with audio aligned,
Output_text blooms where text once chimed,
Tests and proxy snug in pace.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 70.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and clearly summarizes the main change: removing the OpenAI-Beta header that was causing GA Realtime API to reject connections. It aligns perfectly with the primary objective of fixing the realtime WebSocket connection issue.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/realtime-drop-beta-header

---

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[claude]

Looks good — clean removal of the beta header from both the proxy and e2e test, with a clear comment explaining the upstream API change. No remaining references to OpenAI-Beta in the codebase.

[gemini-code-assist]

Code Review

This pull request removes the "OpenAI-Beta: realtime=v1" header from the WebSocket connection headers in both the end-to-end tests and the proxy implementation. This change is necessary because OpenAI's GA Realtime API now rejects the beta header with a "beta_api_shape_disabled" error. I have no feedback to provide as there were no review comments.

[claude]

🟡 Nit: Unlike audio.output (where the isinstance(voice, str) assertion catches a missing key), a missing audio.input passes silently here — None or {} gives {}, then {}.get("turn_detection") is None, and isinstance(None, (dict, type(None))) is True.

Consider asserting input exists as a dict, mirroring the audio assertion on line 300:

Suggested change

	input_cfg = audio.get("input") or {}
	assert isinstance(input_cfg.get("turn_detection"), (dict, type(None)))
	input_cfg = audio.get("input") or {}
	assert isinstance(input_cfg, dict) and input_cfg, f"Expected session.audio.input dict, got: {input_cfg!r}"
	assert isinstance(input_cfg.get("turn_detection"), (dict, type(None)))

[claude]

🟡 Nit: Method name still says text_delta but the event migrated to output_text.delta. Consider renaming for grep-ability:

Suggested change

	def test_response_text_delta_format(self, ws_url, ws_headers):
	def test_response_output_text_delta_format(self, ws_url, ws_headers):

[key4ng]

https://github.com/lightseekorg/smg/actions/runs/26249385768/job/77256411786?pr=1516
realtime api test passed