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 is listed with 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, Voice AI, Transcription, and Diarization.

The Reson8 catalog on APIs.io includes 1 Spectral governance ruleset.

Reson8’s developer surface includes documentation, API reference, getting-started guide, engineering blog, signup flow, pricing, authentication, and 22 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

40.3/100 developing ▬ flat Agent 28/100 agent aware Front door AI 3/6 light Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

3 APIs 2 Agent Skills

Speech Recognition Speech-to-Text Voice AI TranscriptionDiarizationMachine Learning Developers

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 40.3/100 · developing

Contract Quality 2.7 / 19

Developer Ergonomics 7.8 / 15

Access Clarity 9.9 / 15

Operational Transparency 1.8 / 10

Contract Governance 1.6 / 9

Discoverability 5.9 / 8

Regulatory Posture 4.1 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 28/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 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

Pagination 0 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the AI & Biometrics regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)

8 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 14.6 — up to +21.4 composite points
Operational Transparency scores 18.4 — up to +10.6 composite points
Contract Governance scores 18.2 — up to +9.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/reson8/apis.yml: open an issue on github.com/api-evangelist/reson8 to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

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.

Open Collections 3

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

Reson8 Speech-to-Text Auth API

OPEN COLLECTION

Reson8 Speech-to-Text Auth Custom Models API

OPEN COLLECTION

Reson8 Speech-to-Text Auth Speech to Text API

OPEN COLLECTION

Agent Skills 2

Packaged agent skills for driving this provider's APIs from an AI assistant.

Create and maintain a custom model

AGENT SKILL

Transcribe a prerecorded audio file

AGENT SKILL

Reson8 API pricing

Prices published by Reson8, read 2026-10-07 from www.reson8.dev/#pricing.

Plan	Price
Free	€0 Includes: 600 credits / month (10 h prerecorded), 1 concurrent connection, Basic support
Pro	€20/ mo Includes: 6,000 credits / month (100 h prerecorded), 20 concurrent connections, Standard support
Growth	€100/ mo Includes: 30,000 credits / month (500 h prerecorded), 100 concurrent connections, Priority support
Enterprise	Custom credit volume & pricing Includes: Custom concurrency, Dedicated support, On-prem / VPC deployment

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

Reson8 Plans Pricing

4 plans

PLANS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Reson8

SLA

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Reson8 API Rules

62 rules · 58 errors 1 warnings 3 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Reson8 Openapi Overlay

3 actions · update · reson8-openapi.yml

DERIVED

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

X-MCPServerCandidate

LLMsTxt

WellKnown

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conventions

Idempotency

ErrorCatalog

Lifecycle

Conformance

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 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

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)

aid: reson8
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: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  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: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Speech Recognition
- Speech-to-Text
- Voice AI
- Transcription
- Diarization
- Machine Learning
- Developers
tags_raw:
- Speech Recognition
- Speech-to-Text
- ASR
- Voice AI
- Transcription
- Diarization
- Machine Learning
- Developers
- Machine-Learning
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:
  - Authentication
  tags_raw:
  - 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
  tags_raw:
  - 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: Plans
  url: plans/reson8-plans-pricing.yml
- 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: X-MCPServerCandidate
  url: mcp/reson8-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/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

Reson8 API — frequently asked questions

Does Reson8 have an API?

Yes. APIs.io lists 3 APIs from Reson8, including Reson8 Auth API, Reson8 Custom Models API and Reson8 Speech to Text API.

Is there an OpenAPI specification for the Reson8 API?

Yes. APIs.io indexes 3 OpenAPI specifications for Reson8, each linked for download from this page.

How do I authenticate with the Reson8 API?

Reson8 uses bearer-token authentication (apiKey/http-bearer · 3 schemes). The details are profiled on APIs.io as Reson8 Authentication.

How much does the Reson8 API cost?

Reson8 publishes its prices; its Free plan is €0 as of 2026-10-07. APIs.io lists 4 pricing plans for Reson8, with each plan's price, limits and inclusions under Pricing on this page.

Is the Reson8 API ready for AI agents?

Reson8 has a Kin Score of 40.3 out of 100 (developing) and an Agent Readiness score of 28.1 (agent-aware), scored by API Evangelist on 2026-11-06.

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