Speechmatics launches Agent STT, powered by its Linden model, for voice agents
Confirmed
The takeaway
On 2026-09-17 Speechmatics launched Agent STT, a speech-to-text API built for production voice agents and powered by its new Linden 1 model.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- 2 of 5
- Last verified
- 29 September 2026
Your AI and this story
- GPT-6 Astra140 days after its cutoff
- Claude Opus 5.579 days after its cutoff
- Gemini 4 Hydrogen170 days after its cutoff
- Grok 4.7109 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 79 days before it.
Key facts
- Model: linden-1, served on a new /v2/agent endpoint; 55+ languages; segments finalized in under 350 ms
- Pipecat STT benchmark (vendor-cited): 1.05% pooled semantic error rate, 369 ms median finalization, on the speed/accuracy Pareto frontier of 23 streaming models
- Pricing: $0.30/hour at launch, $0.16/hour with volume discount
- Custom vocabulary up to 1,000 terms, live diarization and speaker ID; available via API, Pipecat and LiveKit
- Follows Melia 1 (2026-06-17), Speechmatics’ code-switching multilingual batch model across 55+ languages
What happened
Speechmatics, the UK speech-recognition company, shipped a separate STT product for LLM voice agents. Its Linden 1 model is tuned for the errors that break calls: a changed digit in an account number, a missed negation, a dropped one-word confirmation. Output comes as speaker-attributed segments with turn messages, ready to hand to an LLM.
Why it matters
Voice-agent STT is now a separate product category (Deepgram Flux, AssemblyAI Universal-3.x Pro Realtime, Cartesia Ink-2, Speechmatics Agent STT). Vendors compete on turn detection, semantic errors and finalization latency, not only average WER. The benchmark numbers are Speechmatics’ reading of Pipecat’s public benchmark, not an independent audit.
Sources
5 sources from 4 sites. Numbers match the chips in the text.
5 sources: 4 primary, 1 press
Primary
- Speechmatics press release (GlobeNewswire): Agent STTglobenewswire.com, official
- Speechmatics Agent STT product pagespeechmatics.com, official
- Speechmatics docs: models (Linden 1, Melia 1)docs.speechmatics.com, docs
- Speechmatics: Introducing Meliaspeechmatics.com, official
Press
- HackerNoon: Pipecat benchmarked 23 real-time STT modelshackernoon.com, press
Changes
- Filed