TonePerfect (Pronunciation Assessment API)

TonePerfect offers an AI‑powered pronunciation assessment API for language learning applications. It supports ten languages and provides a single endpoint that returns a detailed score (0‑100) for the whole sentence, each word, and individual sounds, including tone information for Mandarin. The service includes free tier credits, transparent pricing, and robust error handling, making it suitable for developers integrating speech evaluation into apps.

TonePerfect (Pronunciation Assessment API) publishes 3 API contracts indexed on the APIs.io network: Assessment API, Capabilities API, and Utilities API. Tagged areas include Company, Artificial Intelligence, Speech, Language Learning, and Pronunciation.

The TonePerfect (Pronunciation Assessment API) catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

TonePerfect (Pronunciation Assessment API)’s developer surface includes authentication, pricing, changelog, engineering blog, getting-started guide, documentation, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

45.4/100 developing ▼ -10.1 Agent 38/100 agent ready Heartbeat 100/100 alive Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

1 published contract

Company Artificial Intelligence Speech Language Learning Pronunciation

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

AI Model Services

AE-110

Assessment

POST /v1/assess

Kin Score

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

Composite quality — 45.4/100 · developing

Contract Quality 11.3 / 19

Developer Ergonomics 4.7 / 15

Access Clarity 9.3 / 15

Operational Transparency 2.1 / 10

Contract Governance 2.0 / 9

Discoverability 4.8 / 8

Regulatory Posture 2.9 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 38/100 · 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 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 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 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) 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
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
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)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

6 more unmet checks in the Agent Readiness table above.

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

Developer Ergonomics scores 31.0 — up to +13.8 composite points
Operational Transparency scores 21.1 — up to +10.3 composite points
Contract Quality scores 60.5 — up to +9.9 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/toneperfect/apis.yml: open an issue on github.com/api-evangelist/toneperfect 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.

TonePerfect (Pronunciation Assessment API) Assessment API

The Assessment API from TonePerfect (Pronunciation Assessment API) — 1 operation(s) for assessment.

TonePerfect (Pronunciation Assessment API) Capabilities API

The Capabilities API from TonePerfect (Pronunciation Assessment API) — 1 operation(s) for capabilities.

TonePerfect (Pronunciation Assessment API) Utilities API

The Utilities API from TonePerfect (Pronunciation Assessment API) — 3 operation(s) for utilities.

TonePerfect (Pronunciation Assessment API) pricing

Prices published by TonePerfect (Pronunciation Assessment API), read 2026-10-08 from api.toneperfect.app/pricing/.

Plan	Price
Starter	$10/ month
Builder	$50/ month
Scale	$150/ month

Plan details, limits and sources →

Billed by: seat · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Toneperfect Plans Pricing

3 plans

PLANS

Toneperfect Price Estimates

0 plans

PLANS

Service Levels 1

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

TonePerfect (Pronunciation Assessment API)

SLA

FinOps 1

Cost, billing, and metering signals for API financial operations.

Toneperfect Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Toneperfect Context

11 classes · 62 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

TonePerfect (Pronunciation Assessment API) API Rules

14 rules · 12 errors 1 warnings 1 info

SPECTRAL

JSON Schema 4

Standalone JSON Schema definitions for this provider's data models.

Assessment

19 properties

JSON SCHEMA

Capabilities

3 properties

JSON SCHEMA

CompactAssessment

11 properties

JSON SCHEMA

StatusWindow

6 properties

JSON SCHEMA

Security Posture 2

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

Toneperfect Authentication

1 scheme

SECURITY

Toneperfect Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Toneperfect Agentic Access

5 operations · 2 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Login

GettingStarted

GettingStarted

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

Design & Contract 8

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Idempotency

Conventions

ErrorCatalog

Conformance

Scroll for all 8

Build 2

SDKs, sample code, and the tooling you integrate with

Packages

Packages

SDKs

SDKs

Access & Security 3

Authentication, authorization, and security posture

Authentication

Authentication

Security

Security

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

StatusPage

StatusPage

ChangeLog

ChangeLog

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 2

The organization behind the API

Blog

Blog

Website

Website

Other 3

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: toneperfect
name: TonePerfect (Pronunciation Assessment API)
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://api.toneperfect.app/static/og-image.png
description: TonePerfect offers an AI‑powered pronunciation assessment API for language learning applications. It supports
  ten languages and provides a single endpoint that returns a detailed score (0‑100) for the whole sentence, each word, and
  individual sounds, including tone information for Mandarin. The service includes free tier credits, transparent pricing,
  and robust error handling, making it suitable for developers integrating speech evaluation into apps.
url: https://raw.githubusercontent.com/api-evangelist/toneperfect/refs/heads/main/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-08 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-08'
modified: '2026-10-08'
tags:
- Company
- Artificial Intelligence
- Speech
- Language Learning
- Pronunciation
tags_raw:
- Company
- AI
- Speech
- Language-Learning
- Pronunciation
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: CapabilityMap
  url: capabilities/toneperfect-capability-edges.yml
  name: TonePerfect (Pronunciation Assessment API) Business Capability Map
- type: AgenticAccess
  url: agentic-access/toneperfect-agentic-access.yml
- type: Plans
  url: plans/toneperfect-plans-pricing.yml
- type: Spectral
  url: rules/toneperfect-rules.yml
- type: JSONLD
  url: json-ld/toneperfect-context.jsonld
- type: Vocabulary
  url: vocabulary/toneperfect-vocabulary.yml
- type: DataModel
  url: data-model/toneperfect-data-model.yml
- type: Idempotency
  url: conventions/toneperfect-conventions.yml
- type: Conventions
  url: conventions/toneperfect-conventions.yml
- type: Authentication
  url: authentication/toneperfect-authentication.yml
- type: ErrorCatalog
  url: errors/toneperfect-problem-types.yml
- type: Conformance
  url: conformance/toneperfect-conformance.yml
- type: LLMsTxt
  url: llms/toneperfect-llms.txt
- type: Hosts
  url: hosts/toneperfect-hosts.yml
- type: Vendors
  url: vendors/toneperfect-vendors.yml
- type: Packages
  url: packages/toneperfect-packages.yml
- type: TermsOfService
  url: https://api.toneperfect.app/terms/
- type: StatusPage
  url: https://api.toneperfect.app/status/
- type: Security
  url: https://api.toneperfect.app/security/
- type: SDKs
  url: https://api.toneperfect.app/sdk/
- type: PrivacyPolicy
  url: https://api.toneperfect.app/privacy/
- type: Pricing
  url: https://api.toneperfect.app/pricing/
- type: Login
  url: https://api.toneperfect.app/login
- type: ChangeLog
  url: https://api.toneperfect.app/changelog/
- type: Blog
  url: https://api.toneperfect.app/blog/
- type: GettingStarted
  url: https://api.toneperfect.app/quickstart/
- type: DomainSecurity
  url: security/toneperfect-domain-security.yml
- type: Website
  url: https://api.toneperfect.app
- type: Documentation
  url: https://api.toneperfect.app/docs
apis:
- aid: toneperfect:toneperfect-assessment-api
  name: TonePerfect (Pronunciation Assessment API) Assessment API
  description: The Assessment API from TonePerfect (Pronunciation Assessment API) — 1 operation(s) for assessment.
  humanURL: https://api.toneperfect.app/docs
  tags:
  - Assessment
  properties:
  - type: OpenAPI
    url: openapi/toneperfect-assessment-api-openapi.yml
  - type: JSONSchema
    url: json-schema/toneperfect-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-capabilities-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-compact-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-status-window-schema.json
- aid: toneperfect:toneperfect-capabilities-api
  name: TonePerfect (Pronunciation Assessment API) Capabilities API
  description: The Capabilities API from TonePerfect (Pronunciation Assessment API) — 1 operation(s) for capabilities.
  humanURL: https://api.toneperfect.app/docs
  tags:
  - Capabilities
  properties:
  - type: OpenAPI
    url: openapi/toneperfect-capabilities-api-openapi.yml
  - type: JSONSchema
    url: json-schema/toneperfect-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-capabilities-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-compact-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-status-window-schema.json
- aid: toneperfect:toneperfect-utilities-api
  name: TonePerfect (Pronunciation Assessment API) Utilities API
  description: The Utilities API from TonePerfect (Pronunciation Assessment API) — 3 operation(s) for utilities.
  humanURL: https://api.toneperfect.app/docs
  tags:
  - Utilities
  properties:
  - type: OpenAPI
    url: openapi/toneperfect-utilities-api-openapi.yml
  - type: JSONSchema
    url: json-schema/toneperfect-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-capabilities-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-compact-assessment-schema.json
  - type: JSONSchema
    url: json-schema/toneperfect-status-window-schema.json
x-submission-notes: Solo founder, gmail contact. Domain toneperfect.app; submitter asks for one API only.
x-submission-probe: root/docs 200; openapi.json 200 (OpenAPI 3.1); llms.txt 200; soft-404 clean (404)
x-submitted-by: nicolas.maissouradze@gmail.com (apis.io/add, 2026-10-07T07:41:08.244Z)
x-enrichment:
  date: '2026-10-08'
  status: enriched
  artifacts_added: 19
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

TonePerfect (Pronunciation Assessment API) — frequently asked questions

Does TonePerfect (Pronunciation Assessment API) have an API?

Yes. APIs.io lists 3 APIs from TonePerfect (Pronunciation Assessment API), including TonePerfect (Pronunciation Assessment API) Assessment API, TonePerfect (Pronunciation Assessment API) Capabilities API and TonePerfect (Pronunciation Assessment API) Utilities API.

Is there an OpenAPI specification for the TonePerfect (Pronunciation Assessment API)?

Yes. APIs.io indexes 3 OpenAPI specifications for TonePerfect (Pronunciation Assessment API), each linked for download from this page.

How do I authenticate with the TonePerfect (Pronunciation Assessment API)?

TonePerfect (Pronunciation Assessment API) uses bearer-token authentication (1 scheme). The details are profiled on APIs.io as Toneperfect Authentication.

How much does the TonePerfect (Pronunciation Assessment API) cost?

TonePerfect (Pronunciation Assessment API) publishes its prices; its Starter plan is $10/ month as of 2026-10-08. APIs.io lists 3 pricing plans for TonePerfect (Pronunciation Assessment API), with each plan's price, limits and inclusions under Pricing on this page.

Is the TonePerfect (Pronunciation Assessment API) ready for AI agents?

TonePerfect (Pronunciation Assessment API) has a Kin Score of 45.4 out of 100 (developing) and an Agent Readiness score of 38.4 (agent-ready), scored by API Evangelist on 2026-11-06.

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