Take the resolver and its timeout as parameters of the bounded helper and
bind the vertex one once at module level, so the timeout tests drive an
injected fake instead of patching a shared singleton.
A /v1/realtime connection to a Vertex AI Live model accepted the WebSocket
upgrade and then went silent: a stalled Google OAuth token fetch blocked the
handler before any session event, and the eventual failure closed the socket
with a bare 1011 and no error event, so callers saw an open socket, no frames,
and no reason.
Bound the pre-session token fetch with
REALTIME_CREDENTIAL_RESOLUTION_TIMEOUT_SECONDS (20s default) and, on any
realtime failure, send an OpenAI-style error event before closing with a reason
that names the failure. Close reasons are truncated by bytes, not characters,
since an over-long reason makes the close frame itself fail.
_with_resolved_session_model was overwriting the nested
input_audio_transcription.model and audio.input.transcription.model with the
realtime conversation model, silently replacing a caller's transcription model
(e.g. whisper-1) since those are a different model than the realtime deployment.
It now only resolves the top-level session model.
Also restores session.model taking precedence over the top-level model in
acreate_realtime_client_secret, matching the proxy's own
_prepare_client_secret_session ordering and avoiding a backwards-incompatible flip.
Adds routing coverage for arealtime_calls (api_base resolution) and
acreate_realtime_transcription_session (api_key resolution) so all three realtime
HTTP endpoints have router credential-resolution tests, plus regression tests for
the two fixes above.
Co-authored-by: Cursor <cursoragent@cursor.com>
