Complete the symmetry left by #3214: ChannelManager._resolve_transcription_base
already resolves providers.openai.api_base, but BaseChannel.transcribe_audio
instantiated OpenAITranscriptionProvider without forwarding it, and the provider
__init__ did not accept the parameter. Self-hosted OpenAI-compatible Whisper
endpoints (LiteLLM, vLLM, etc.) configured via config.json were therefore
ignored for the OpenAI backend.
- OpenAITranscriptionProvider.__init__ now accepts api_base with env fallback
(OPENAI_TRANSCRIPTION_BASE_URL) matching the Groq pattern.
- BaseChannel.transcribe_audio forwards self.transcription_api_base to OpenAI.
- Tests mirror the existing Groq coverage: manager propagation for provider
"openai", BaseChannel-to-provider argument passing, and provider default vs
override for api_url.
Fully backward-compatible: when api_base is None and the env var is unset,
the default https://api.openai.com/v1/audio/transcriptions is used.
Refs #3213, follow-up to #3214.
get_definitions() sorts tools on every LLM iteration for prompt cache
stability. Cache the sorted result and invalidate on register/unregister
so the sort only runs when the tool set actually changes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Three fixes in the API upload handling:
1. Multipart uploads now prefix filenames with a UUID to prevent
overwrites when two requests upload files with the same name.
2. JSON image_url content blocks with remote HTTPS URLs now return
a 400 error instead of silently dropping the image.
3. Model validation runs for both JSON and multipart requests,
fixing an inconsistency where multipart bypassed the check.