AssemblyAI

Streaming turn model built for voice agents, plus strong async models.

All prices are the vendor’s public list price — 0% markup. Extra provider knobs pass through untouched via provider_params.

Model	Modes	List price	Diarization	Word timings
`assemblyai/universal-3-5-pro`	streaming	$0.45/session-hr	✓	✓
`assemblyai/universal-streaming-english`	streaming	$0.15012/session-hr	✓	✓
`assemblyai/universal-streaming-multilingual`	streaming	$0.15012/session-hr	✓	✓
`assemblyai/universal-2`	batch	$0.20988/hr	✓	✓

Provider options

Reach past the unified surface with provider_params — forwarded streaming → WebSocket query parameters; batch → job fields. Typed in the SDKs as {provider}Params interfaces (providerParams option / provider_params= kwarg).

Param	Type	Default	Applies to	What it does
`end_of_turn_confidence_threshold`	number	`0.4`	streaming	Confidence needed to declare end of turn
`min_turn_silence`	integer	—	streaming	Minimum silence (ms) before a turn can end
`max_turn_silence`	integer	—	streaming	Silence (ms) that forces end of turn
`vad_threshold`	number	—	streaming	Voice-activity detection sensitivity
`continuous_partials`	boolean	`false`	streaming	Emit partials continuously instead of on change
`max_speakers`	integer	—	streaming	Cap for streaming diarization
`language_detection`	boolean	`false`	streaming · batch	Auto-detect the spoken language
`domain`	`medical-v1`	—	streaming	Domain-tuned recognition
`prompt`	string	—	streaming	Free-text context to bias recognition
`redact_pii`	boolean	`false`	streaming · batch	Redact personally identifiable information
`inactivity_timeout`	integer	—	streaming	Close the vendor session after this many silent seconds
`mode`	`max_accuracy` · `balanced` · `min_latency`	—	streaming	universal-3-5-pro: latency/accuracy preset

Try it

curl -s https://api.speechrouter.ai/v1/audio/transcriptions \
  -H "Authorization: Bearer $SPEECHROUTER_API_KEY" \
  -F model=assemblyai/universal-2 \
  -F file=@audio.wav

_{Generated from the gateway catalog — the billing engine’s own source of truth.}