Voice AI Infrastructure

Secure voice AI infrastructure.
One API. 30+ providers.

slng sits between your voice agent and every STT, TTS, and LLM provider. Audio in. Audio out. Model selection, regional routing, noise cancellation, and automatic failover — handled at the infrastructure layer.

Request access → Try the playground →
⚡

Model selection

Route each call to the best-fit STT, TTS, or LLM model based on latency, cost, accuracy, or language requirements — without changing your code.

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Regional routing

Pin processing to specific regions for data residency and regulatory compliance. HIPAA, GDPR, SOC 2, and ISO 27001 supported out of the box.

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Noise cancellation

Automatic audio preprocessing before transcription. Background noise, echo, and low-quality mic input cleaned up at the infrastructure layer.

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Automatic failover

If a provider goes down or rate-limits, slng reroutes instantly to the next best option. No downtime, no code changes, no incident at 3am.

API

One endpoint. Any provider.

TTS — any model, any region Regional compliance 
# Text-to-speech, any model, any region
curl -X POST https://api.slng.ai/v1/tts/slng/rime/arcana:3-en \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "text": "Hello from production", "speaker": "astra" }'
# Pin processing to a specific region for compliance
curl -X POST https://api.slng.ai/v1/tts/slng/rime/arcana:3-en \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "X-Region: eu-west-1" \
  -d '{ "text": "Hello from production", "speaker": "astra" }'
Your orchestrator, your LLM, your agent logic — none of it changes.
Providers

30+ providers. Zero lock-in.

STT
Deepgram OpenAI Whisper AssemblyAI Google STT Azure Speech AWS Transcribe ElevenLabs Scribe Grok STT Speechmatics + more
TTS
ElevenLabs Deepgram Aura OpenAI TTS Cartesia PlayHT AWS Polly Google TTS Azure Neural TTS Rime AI + more
LLM
OpenAI GPT Anthropic Claude Google Gemini Grok Groq Azure OpenAI AWS Bedrock Mistral + more

New providers added regularly. Your integration stays the same.

How it works

Drop in. Ship faster.

01

Point your agent at slng

Replace your provider endpoint with the slng API. Your orchestrator, LLM, and agent logic stay exactly as they are. One key, one endpoint.

02

We route to the best provider

slng selects the optimal STT, TTS, and LLM model per call — based on latency, cost, language, and your compliance constraints. Everything runs faster from your first call.

03

Failover and cleanup — automatic

Provider rate-limits? We reroute. Noisy audio? We clean it before transcription. Regional requirement? We pin it. None of this is your problem.

Compliance-ready
HIPAA GDPR SOC 2 ISO 27001

Deploy voice models in chosen global regions to meet data residency, latency, and regulatory requirements. Built for regulated industries.

Early access

Request access

slng is in private beta. Drop your email — we'll reach out to get you connected to the API and answer any infrastructure questions.