AssemblyAI streaming transcription names the model with the parameter AssemblyAI still accepts

Streaming transcription opened its socket with the retired singular speech_model parameter, which AssemblyAI refuses. It served no streaming transcription at all in the week to 2026-08-02: 37 attempts, 37 failures, 35 of them that one rejection. The parameter is now the plural speech_models, matching the batch path, which already sent the plural form and was unaffected.

The streaming socket query named the model with speech_model. AssemblyAI retired that spelling and answers that it is deprecated in favour of speech_models, refusing the connection before any audio is sent. Measured over the week to 2026-08-02, AssemblyAI streaming recorded 37 attempts and zero successful selections, and 35 of the 37 failures were that single response.

AssemblyAI was not unavailable during this period. The rejection was produced by the shape of the request the router sent, so it was invisible as provider health and presented instead as a quietly shorter failover chain: a caller whose key ranked AssemblyAI first was served by whichever candidate ranked behind it, with no error.

Batch transcription was never affected. It already sent the plural speech_models as a single-element array, so the streaming and batch paths now spell the same request the same way.

Action: No migration is required. Keys that rank AssemblyAI first for streaming transcription will begin reaching it instead of falling through to the next candidate, so the provider serving a given stream may change. Pin explicitly with X-Speko-Allow to keep a request on one vendor.