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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.

agent native

Solid contracts, transparent operations, and an easy start — typically complete on four or five facets with one clear soft spot.

Kin Score

API Evangelist profiles SLNG the way a machine reads it — 23 machine-readable artifacts across 15 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — SLNG scores 60.4/100 (strong), with a separate agent-readiness read of 71/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

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

How we profile SLNG

Each block below is one kind of artifact we hold for SLNG. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 15

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

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 within the panel for all 15 ·

MCP Servers 1

Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.

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

slng-mcp.yml

MCP SERVER

Event Specifications 3

Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.

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 — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

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

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

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

Every other property we hold for SLNG — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Build 4

SDKs, sample code, and the tooling you integrate with

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

← All providers · Data indexed from github.com/api-evangelist/slng · machine-readable index on apis.io