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 27 more developer resources.

🌐 Visit website 📡 Source on GitHub

54.4/100 strong ▬ flat Agent 30/100 agent ready saas Full breakdown ↓
scored 2026-09-06 · rubric v0.19.0

7 APIs

Company Speech Voice Speech-to-Text Text-to-Speech Voice AI Voice Agents Transcription Speech Recognition Artificial Intelligence API Gateway

Kin Score

Kin Score How this is scored →
scored 2026-09-06 · rubric v0.19.0

Composite quality — 54.4/100 · strong

Contract Quality 17.6 / 25

Developer Ergonomics 16.3 / 20

Access Clarity 9.5 / 20

Operational Transparency 2.4 / 13

Contract Governance 0.5 / 12

Discoverability 8.2 / 10

Agent readiness — 30/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 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

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. 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. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 15

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

Open Collections 16

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions

ErrorCatalog

Lifecycle

DataModel

Conformance

Build 5

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace

PostmanWorkspace

GitHubOrganization

Packages

SDKs

CLI

Access & Security 4

Authentication, authorization, and security posture

TrustCenter

Compliance

Authentication

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

Support

Support

ChangeLog

ChangeLog

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 1

The organization behind the API

Blog

Blog

Other 4

Properties that don't map to a standard resource type

Overlay

Overlay

Overlay

Overlay

Source (apis.yml)

aid: slng
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  - sandbox
  generated: '2026-09-03'
  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: '0.23'
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
tags_raw:
- 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
  tags_raw:
  - 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: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/slng/overview
- 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: X-MCPServerCandidate
  url: mcp/slng-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- 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

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SLNG

APIs 15

Postman Collections 15

Open Collections 16

Event Specifications 3

Security Posture 3

Agentic Access 1

Get Started 4

Documentation 2

Agent Surfaces 4

Design & Contract 5

Build 5

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