Reson8

Reson8 (Resonate Labs B.V.) is a Balderton Capital-backed speech-recognition company offering an infrastructure-grade automatic speech recognition (ASR) API. Its differentiator is text-based, hyper-custom domain adaptation: feed up to ~1M tokens of domain vocabulary and a custom model adapts in under 60 seconds with no audio datasets or fine-tuning, cutting word error rate versus generic engines. The v1 API at api.reson8.dev provides realtime WebSocket streaming, turn-level events for conversational voice agents, prerecorded file transcription, speaker diarization, and custom-model phrase management across ten European languages, on EU-hosted infrastructure with zero audio retention.

Reson8 publishes 3 APIs on the APIs.io network: Auth API, Custom Models API, and Speech to Text API. Tagged areas include Speech Recognition, Speech-to-Text, ASR, Voice AI, and Transcription.

Reson8’s developer surface includes documentation, API reference, getting-started guide, engineering blog, signup flow, pricing, authentication, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub
52.7/100 developing ▬ flat Agent 64/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
3 APIs 1 MCP Servers
Speech RecognitionSpeech-to-TextASRVoice AITranscriptionDiarizationMachine LearningDevelopers

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 52.7/100 · developing
Contract Quality 15.6 / 25
Developer Ergonomics 13.9 / 20
Commercial Clarity 10.5 / 20
Operational Transparency 2.7 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 64/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 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/reson8: 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 3

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

Reson8 Auth API

Exchange an API key for a short-lived access token.

Reson8 Custom Models API

Domain adaptation via custom phrase models.

Reson8 Speech to Text API

Realtime, turn-level, and prerecorded transcription.

MCP Servers 1

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

reson8-mcp.yml

MCP SERVER

Security Posture 3

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

Reson8 Authentication

apiKey/http-bearer · 3 schemes

SECURITY

Reson8 Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Reson8 Trust Center

trust center published

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 SignUp
SignUp

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer
MCPServer
 LLMsTxt
LLMsTxt
 WellKnown
WellKnown
 AgentSkill
AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 Idempotency
Idempotency
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 Conformance
Conformance
 DataModel
DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages
 SDKs
SDKs

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 TrustCenter
TrustCenter
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

StatusPage
StatusPage

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

Overlay
Overlay

Source (apis.yml)

apis.yml Raw ↑ 
aid: reson8
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/reson8.png
name: Reson8
description: 'Reson8 (Resonate Labs B.V.) is a Balderton Capital-backed speech-recognition company offering an infrastructure-grade
  automatic speech recognition (ASR) API. Its differentiator is text-based, hyper-custom domain adaptation: feed up to ~1M
  tokens of domain vocabulary and a custom model adapts in under 60 seconds with no audio datasets or fine-tuning, cutting
  word error rate versus generic engines. The v1 API at api.reson8.dev provides realtime WebSocket streaming, turn-level events
  for conversational voice agents, prerecorded file transcription, speaker diarization, and custom-model phrase management
  across ten European languages, on EU-hosted infrastructure with zero audio retention.'
url: https://raw.githubusercontent.com/api-evangelist/reson8/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- balderton-capital
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Speech Recognition
- Speech-to-Text
- ASR
- Voice AI
- Transcription
- Diarization
- Machine Learning
- Developers
apis:
- aid: reson8:reson8-auth-api
  name: Reson8 Auth API
  description: Exchange an API key for a short-lived access token.
  humanURL: https://docs.reson8.dev/
  baseURL: https://api.reson8.dev/v1
  tags:
  - Auth
  properties:
  - type: OpenAPI
    url: openapi/reson8-auth-api-openapi.yml
  - type: APIReference
    url: https://docs.reson8.dev/api/
  - type: Documentation
    url: https://docs.reson8.dev/
  - type: GettingStarted
    url: https://docs.reson8.dev/
  - type: Authentication
    url: authentication/reson8-authentication.yml
- aid: reson8:reson8-custom-models-api
  name: Reson8 Custom Models API
  description: Domain adaptation via custom phrase models.
  humanURL: https://docs.reson8.dev/
  baseURL: https://api.reson8.dev/v1
  tags:
  - Custom Models
  properties:
  - type: OpenAPI
    url: openapi/reson8-custom-models-api-openapi.yml
  - type: APIReference
    url: https://docs.reson8.dev/api/
  - type: Documentation
    url: https://docs.reson8.dev/
  - type: GettingStarted
    url: https://docs.reson8.dev/
  - type: Authentication
    url: authentication/reson8-authentication.yml
- aid: reson8:reson8-speech-to-text-api
  name: Reson8 Speech to Text API
  description: Realtime, turn-level, and prerecorded transcription.
  humanURL: https://docs.reson8.dev/
  baseURL: https://api.reson8.dev/v1
  tags:
  - Speech to Text
  properties:
  - type: OpenAPI
    url: openapi/reson8-speech-to-text-api-openapi.yml
  - type: APIReference
    url: https://docs.reson8.dev/api/
  - type: Documentation
    url: https://docs.reson8.dev/
  - type: GettingStarted
    url: https://docs.reson8.dev/
  - type: Authentication
    url: authentication/reson8-authentication.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/reson8-domain-security.yml
- type: Website
  url: https://www.reson8.dev/
- type: DeveloperPortal
  url: https://console.reson8.dev/
- type: Documentation
  url: https://docs.reson8.dev/
- type: APIReference
  url: https://docs.reson8.dev/api/
- type: GettingStarted
  url: https://docs.reson8.dev/
- type: Blog
  url: https://www.reson8.dev/blog
- type: GitHubOrganization
  url: https://github.com/reson8labs
- type: SignUp
  url: https://console.reson8.dev/
- type: Pricing
  url: https://www.reson8.dev/#pricing
- type: TermsOfService
  url: https://www.reson8.dev/terms
- type: PrivacyPolicy
  url: https://www.reson8.dev/privacy-policy
- type: StatusPage
  url: https://status.reson8.dev
- type: TrustCenter
  url: https://trust.reson8.dev/
- type: Authentication
  url: authentication/reson8-authentication.yml
- type: Conventions
  url: conventions/reson8-conventions.yml
- type: Idempotency
  url: conventions/reson8-conventions.yml
- type: ErrorCatalog
  url: errors/reson8-error-codes.yml
- type: Lifecycle
  url: lifecycle/reson8-lifecycle.yml
- type: Packages
  url: packages/reson8-packages.yml
- type: SDKs
  url: packages/reson8-packages.yml
- type: MCPServer
  url: mcp/reson8-mcp.yml
- type: LLMsTxt
  url: llms/reson8-llms.txt
- type: Overlay
  url: overlays/reson8-openapi-overlay.yaml
- type: Conformance
  url: conformance/reson8-conformance.yml
- type: DataModel
  url: data-model/reson8-data-model.yml
- type: WellKnown
  url: well-known/reson8-well-known.yml
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 17
  pass: local-v1