SLNG

SLNG is a compliance-first speech AI gateway that gives developers a single, unified API for speech-to-text, text-to-speech, and LLM-driven voice agents across 30+ models from providers like Deepgram, Rime, Cartesia, ElevenLabs, and OpenAI Whisper. The platform acts as an execution layer between an orchestrator and the models, routing each request to in-region compute across 60+ regions and 11 sovereign hubs for low latency and local data residency (GDPR), with ISO 27001 certification and HIPAA compliance. Every model is reachable over HTTP or streaming WebSocket, with bring-your-own-key billing, batch transcription, pronunciation dictionaries, and per-minute pricing. Founded in Barcelona in 2025 and backed by a pre-seed round led by Earlybird.

SLNG publishes 15 APIs on the APIs.io network, including Account API, Agents API, Calls API, and 12 more. Tagged areas include Company, Speech, Voice, Speech to Text, and Text to Speech.

The SLNG catalog on APIs.io includes 3 event-driven AsyncAPI specifications.

SLNG’s developer surface includes documentation, API reference, getting-started guide, engineering blog, signup flow, pricing, support, and 26 more developer resources.

60.4/100 strong ▬ flat Agent 71/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
15 APIs 1 MCP Servers
CompanySpeechVoiceSpeech to TextText to SpeechVoice AIVoice AgentsTranscriptionSpeech RecognitionArtificial IntelligenceAPI Gateway

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 60.4/100 · strong
Contract Quality 18.2 / 25
Developer Ergonomics 17.4 / 20
Commercial Clarity 12.1 / 20
Operational Transparency 2.7 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 71/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/slng: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 15

Individual APIs this provider publishes, each with its own machine-readable definition.

SLNG Account API

Inspect the authenticated account and organization.

SLNG Agents API

Voice agent CRUD.

SLNG Calls API

Call dispatch and status.

SLNG Catalog API

Discover and inspect available models in the SLNG catalog.

SLNG Deepgram Aura 2 API

Deepgram Aura 2 for conversational voice agents.

SLNG Deepgram Nova 3 API

Deepgram Nova 3 with VAD and speaker diarization.

SLNG Inworld Max 1.5 API

Inworld Max 1.5 for multilingual, expressive synthesis.

SLNG Orpheus English API

Orpheus TTS with emotion control.

SLNG Pronunciation dictionaries API

Manage reusable pronunciation rewrite dictionaries for TTS.

SLNG Rime Arcana v2 API

Rime Arcana v2 TTS with multi-language support.

SLNG Rime Arcana v3 API

Rime Arcana v3 TTS with multilingual support (English, Hindi).

SLNG Rime Coda API

Rime Coda TTS for Bahasa Indonesian.

SLNG Sessions API

Web (non-telephony) sessions.

SLNG Speechmatics API

Create and manage asynchronous transcription jobs.

SLNG Whisper Large v3 API

Whisper Large v3 with 99+ language support.

Scroll for all 15

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

slng-mcp.yml

MCP SERVER

Event Specifications 3

AsyncAPI definitions for this provider's event-driven and streaming APIs.

SLNG Gateway API - SLNG (WebSocket)

SLNG Gateway API

ASYNCAPI

SLNG Gateway API - SLNG STT

SLNG Gateway API

ASYNCAPI

SLNG Gateway API - SLNG TTS

SLNG Gateway API

ASYNCAPI

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Slng Authentication

http · 1 scheme

SECURITY

Slng Domain Security

TLSv1.3 · DMARC

SECURITY

Slng Trust Center

ISO 27001, HIPAA, GDPR

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Slng Agentic Access

43 operations · 31 acting · 1 human-in-the-loop

43 operations · 31 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Build 4

SDKs, sample code, and the tooling you integrate with

Access & Security 4

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 1

The organization behind the API

Other 4

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: slng
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/slng.png
name: SLNG
description: SLNG is a compliance-first speech AI gateway that gives developers a single, unified API for speech-to-text,
  text-to-speech, and LLM-driven voice agents across 30+ models from providers like Deepgram, Rime, Cartesia, ElevenLabs,
  and OpenAI Whisper. The platform acts as an execution layer between an orchestrator and the models, routing each request
  to in-region compute across 60+ regions and 11 sovereign hubs for low latency and local data residency (GDPR), with ISO
  27001 certification and HIPAA compliance. Every model is reachable over HTTP or streaming WebSocket, with bring-your-own-key
  billing, batch transcription, pronunciation dictionaries, and per-minute pricing. Founded in Barcelona in 2025 and backed
  by a pre-seed round led by Earlybird.
url: https://raw.githubusercontent.com/api-evangelist/slng/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- earlybird
x-tier: producer
x-tier-reason: enriched-from-live-api
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- Speech
- Voice
- Speech to Text
- Text to Speech
- Voice AI
- Voice Agents
- Transcription
- Speech Recognition
- Artificial Intelligence
- API Gateway
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: slng:slng-account-api
  name: SLNG Account API
  description: Inspect the authenticated account and organization.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/slng-account-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-agents-api
  name: SLNG Agents API
  description: Voice agent CRUD.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Agents
  properties:
  - type: OpenAPI
    url: openapi/slng-agents-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-calls-api
  name: SLNG Calls API
  description: Call dispatch and status.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Calls
  properties:
  - type: OpenAPI
    url: openapi/slng-calls-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-catalog-api
  name: SLNG Catalog API
  description: Discover and inspect available models in the SLNG catalog.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Catalog
  properties:
  - type: OpenAPI
    url: openapi/slng-catalog-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-deepgram-aura-2-api
  name: SLNG Deepgram Aura 2 API
  description: Deepgram Aura 2 for conversational voice agents.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Deepgram Aura 2
  properties:
  - type: OpenAPI
    url: openapi/slng-deepgram-aura-2-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-deepgram-nova-3-api
  name: SLNG Deepgram Nova 3 API
  description: Deepgram Nova 3 with VAD and speaker diarization.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Deepgram Nova 3
  properties:
  - type: OpenAPI
    url: openapi/slng-deepgram-nova-3-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-inworld-max-1-5-api
  name: SLNG Inworld Max 1.5 API
  description: Inworld Max 1.5 for multilingual, expressive synthesis.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Inworld Max 1.5
  properties:
  - type: OpenAPI
    url: openapi/slng-inworld-max-1-5-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-orpheus-english-api
  name: SLNG Orpheus English API
  description: Orpheus TTS with emotion control.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Orpheus English
  properties:
  - type: OpenAPI
    url: openapi/slng-orpheus-english-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-pronunciation-dictionaries-api
  name: SLNG Pronunciation dictionaries API
  description: Manage reusable pronunciation rewrite dictionaries for TTS.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Pronunciation dictionaries
  properties:
  - type: OpenAPI
    url: openapi/slng-pronunciation-dictionaries-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-rime-arcana-v2-api
  name: SLNG Rime Arcana v2 API
  description: Rime Arcana v2 TTS with multi-language support.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Rime Arcana v2
  properties:
  - type: OpenAPI
    url: openapi/slng-rime-arcana-v2-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-rime-arcana-v3-api
  name: SLNG Rime Arcana v3 API
  description: Rime Arcana v3 TTS with multilingual support (English, Hindi).
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Rime Arcana v3
  properties:
  - type: OpenAPI
    url: openapi/slng-rime-arcana-v3-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-rime-coda-api
  name: SLNG Rime Coda API
  description: Rime Coda TTS for Bahasa Indonesian.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Rime Coda
  properties:
  - type: OpenAPI
    url: openapi/slng-rime-coda-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-sessions-api
  name: SLNG Sessions API
  description: Web (non-telephony) sessions.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Sessions
  properties:
  - type: OpenAPI
    url: openapi/slng-sessions-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-speechmatics-api
  name: SLNG Speechmatics API
  description: Create and manage asynchronous transcription jobs.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Speechmatics
  properties:
  - type: OpenAPI
    url: openapi/slng-speechmatics-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
- aid: slng:slng-whisper-large-v3-api
  name: SLNG Whisper Large v3 API
  description: Whisper Large v3 with 99+ language support.
  humanURL: https://docs.slng.ai
  baseURL: https://api.slng.ai
  tags:
  - Whisper Large v3
  properties:
  - type: OpenAPI
    url: openapi/slng-whisper-large-v3-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-stt-slng-asyncapi.yml
  - type: AsyncAPI
    url: asyncapi/slng-tts-slng-asyncapi.yml
common:
- type: DeveloperPortal
  url: https://docs.slng.ai
- type: Documentation
  url: https://docs.slng.ai
- type: APIReference
  url: https://docs.slng.ai/api-reference/overview
- type: GettingStarted
  url: https://docs.slng.ai/getting-started
- type: Blog
  url: https://slng.ai/blog
- type: GitHubOrganization
  url: https://github.com/slng-ai
- type: SignUp
  url: https://app.slng.ai
- type: Pricing
  url: https://slng.ai/pricing
- type: TermsOfService
  url: https://slng.ai/legal/terms-of-service
- type: PrivacyPolicy
  url: https://slng.ai/legal/privacy-policy
- type: Support
  url: mailto:support@slng.ai
- type: ChangeLog
  url: changelog/slng-changelog.yml
- type: TrustCenter
  url: https://trust.slng.ai
- type: Compliance
  url: security/slng-trust-center.yml
- type: Authentication
  url: authentication/slng-authentication.yml
- type: DomainSecurity
  url: security/slng-domain-security.yml
- type: AgenticAccess
  url: agentic-access/slng-agentic-access.yml
- type: Packages
  url: packages/slng-packages.yml
- type: SDKs
  url: packages/slng-packages.yml
- type: CLI
  url: cli/slng-cli.yml
- type: MCPServer
  url: mcp/slng-mcp.yml
- type: LLMsTxt
  url: llms/slng-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: Conventions
  url: conventions/slng-conventions.yml
- type: ErrorCatalog
  url: errors/slng-problem-types.yml
- type: Lifecycle
  url: lifecycle/slng-lifecycle.yml
- type: Sandbox
  url: sandbox/slng-sandbox.yml
- type: DataModel
  url: data-model/slng-data-model.yml
- type: Conformance
  url: conformance/slng-conformance.yml
- type: Overlay
  url: overlays/slng-stt-overlay.yaml
- type: Overlay
  url: overlays/slng-tts-overlay.yaml
- type: Overlay
  url: overlays/slng-agents-overlay.yaml
- type: Overlay
  url: overlays/slng-batch-overlay.yaml
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 38
  pass: local-v1