FlowSpeech

FlowSpeech provides a context‑aware text‑to‑speech service that converts text into human‑like audio with emotion, pause control, and over 30 AI voices. The API supports asynchronous job creation and retrieval of generated audio files, secured via Bearer API‑key authentication.

FlowSpeech publishes 3 API contracts indexed on the APIs.io network: Quota API, Tts API, and Voices API. Tagged areas include Company, Text-to-Speech, Artificial Intelligence, Voice, and Asynchronous.

The FlowSpeech catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

FlowSpeech’s developer surface includes authentication, pricing, documentation, and 19 more developer resources.

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42.0/100 developing Agent 37/100 agent ready Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemium

1 published contract 1 Agent Skills

Company Text-to-Speech Artificial Intelligence Voice Asynchronous

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 42.0/100 · developing

Contract Quality 12.6 / 21

Developer Ergonomics 5.2 / 17

Access Clarity 8.7 / 17

Operational Transparency 0.0 / 11

Contract Governance 3.6 / 10

Discoverability 5.6 / 9

Regulatory Posture 2.6 / 15

Agent readiness — 37/100 · 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 0 / 7

Rate-Limit Signaling 7 / 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 5 / 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% 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 Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link Ask about this →
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →
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) Ask about this →
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks Ask about this →

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 30.4 — up to +13.9 composite points Ask about this →
Operational Transparency scores 0.0 — up to +13.0 composite points Ask about this →
Contract Quality scores 59.5 — up to +10.1 composite points Ask about this →

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.

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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/flowspeech/apis.yml: open an issue on github.com/api-evangelist/flowspeech 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.

FlowSpeech Quota API

The Quota API from FlowSpeech — 1 operation(s) for quota.

FlowSpeech Tts API

The Tts API from FlowSpeech — 3 operation(s) for tts.

FlowSpeech Voices API

The Voices API from FlowSpeech — 1 operation(s) for voices.

Agent Skills 1

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

flowspeech-create-and-retrieve-speech-job

AGENT SKILL

FlowSpeech API pricing

Prices published by FlowSpeech, read 2026-11-08 from flowspeech.io/pricing.

Plan	Price
Free	$0/ month
Basic	$19/ month
Pro	$59/ month
Scale	$189/ month

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

FlowSpeech Plans Pricing

4 plans

PLANS

Semantic Vocabularies 1

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

Flowspeech Context

5 classes · 23 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

FlowSpeech API Rules

45 rules · 43 error-severity 1 warn-severity 1 info-severity

SPECTRAL

JSON Schema 3

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

CreateJob

2 properties

JSON SCHEMA

Job

13 properties

JSON SCHEMA

Quota

5 properties

JSON SCHEMA

Security Posture 2

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

FlowSpeech Authentication

1 scheme

SECURITY

FlowSpeech Domain Security

TLSv1.3 · HSTS

SECURITY

Agentic Access (API Evangelist recommendations) 1

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

FlowSpeech Agentic Access

6 operations · 2 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

AgentSkill

AgentSkill

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

SDKs

SDKs

Packages

Packages

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: flowspeech
name: FlowSpeech
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-13'
  method: derived
image: https://flowspeech.io/logo.png
description: FlowSpeech provides a context‑aware text‑to‑speech service that converts text into human‑like audio with emotion,
  pause control, and over 30 AI voices. The API supports asynchronous job creation and retrieval of generated audio files,
  secured via Bearer API‑key authentication.
url: https://artifacts.apis.io/flowspeech/apis.yml
x-type: company
x-source: harvest:new-submission
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-08 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-08'
modified: '2026-11-08'
tags:
- Company
- Text-to-Speech
- Artificial Intelligence
- Voice
- Asynchronous
tags_raw:
- Company
- Text-to-Speech
- AI
- Voice
- Asynchronous
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/flowspeech-agentic-access.yml
- type: Plans
  url: plans/flowspeech-plans-pricing.yml
- type: Spectral
  url: rules/flowspeech-rules.yml
- type: JSONLD
  url: json-ld/flowspeech-context.jsonld
- type: Vocabulary
  url: vocabulary/flowspeech-vocabulary.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DataModel
  url: data-model/flowspeech-data-model.yml
- type: Idempotency
  url: conventions/flowspeech-conventions.yml
- type: Conventions
  url: conventions/flowspeech-conventions.yml
- type: Authentication
  url: authentication/flowspeech-authentication.yml
- type: ErrorCatalog
  url: errors/flowspeech-problem-types.yml
- type: Conformance
  url: conformance/flowspeech-conformance.yml
- type: Hosts
  url: hosts/flowspeech-hosts.yml
- type: Vendors
  url: vendors/flowspeech-vendors.yml
- type: SDKs
  url: packages/flowspeech-packages.yml
- type: Packages
  url: packages/flowspeech-packages.yml
- type: TermsOfService
  url: https://flowspeech.io/terms-of-service
- type: PrivacyPolicy
  url: https://flowspeech.io/privacy-policy
- type: Pricing
  url: https://flowspeech.io/pricing
- type: DomainSecurity
  url: security/flowspeech-domain-security.yml
- type: Website
  url: https://flowspeech.io/
- type: Documentation
  url: https://flowspeech.io/docs/public-api
apis:
- aid: flowspeech:flowspeech-quota-api
  name: FlowSpeech Quota API
  description: The Quota API from FlowSpeech — 1 operation(s) for quota.
  humanURL: https://flowspeech.io/docs/public-api
  baseURL: https://flowspeech.io
  tags:
  - Quota
  properties:
  - type: OpenAPI
    url: openapi/flowspeech-quota-api-openapi.yml
  - type: JSONSchema
    url: json-schema/flowspeech-quota-schema.json
- aid: flowspeech:flowspeech-tts-api
  name: FlowSpeech Tts API
  description: The Tts API from FlowSpeech — 3 operation(s) for tts.
  humanURL: https://flowspeech.io/docs/public-api
  baseURL: https://flowspeech.io
  tags:
  - Text-to-Speech
  tags_raw:
  - Tts
  properties:
  - type: OpenAPI
    url: openapi/flowspeech-tts-api-openapi.yml
  - type: JSONSchema
    url: json-schema/flowspeech-job-schema.json
  - type: JSONSchema
    url: json-schema/flowspeech-create-job-schema.json
  - type: JSONSchema
    url: json-schema/flowspeech-quota-schema.json
- aid: flowspeech:flowspeech-voices-api
  name: FlowSpeech Voices API
  description: The Voices API from FlowSpeech — 1 operation(s) for voices.
  humanURL: https://flowspeech.io/docs/public-api
  baseURL: https://flowspeech.io
  tags:
  - Voice
  tags_raw:
  - Voices
  properties:
  - type: OpenAPI
    url: openapi/flowspeech-voices-api-openapi.yml
x-submission-notes: 'I represent FlowSpeech and am submitting its text-to-speech API for your catalog. It is a server-side
  REST API with Bearer API-key authentication. Generation is asynchronous: POST /api/v1/tts/jobs creates a job, and GET /api/v1/tts/jobs/{id}
  returns its status and, on success, an audio download URL.'
x-submission-probe: 2026-11-07 200 https://flowspeech.io/ ctl=404
x-enrichment:
  date: '2026-11-08'
  status: enriched
  artifacts_added: 23
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

FlowSpeech API — frequently asked questions

Does FlowSpeech have an API?

Yes. APIs.io lists 3 APIs from FlowSpeech, including FlowSpeech Quota API, FlowSpeech Tts API and FlowSpeech Voices API.

Is there an OpenAPI specification for the FlowSpeech API?

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

How do I authenticate with the FlowSpeech API?

FlowSpeech uses bearer-token authentication (1 scheme). The details are profiled on APIs.io as FlowSpeech Authentication.

How much does the FlowSpeech API cost?

FlowSpeech publishes its prices; its Free plan is $0/ month as of 2026-11-08. APIs.io lists 4 pricing plans for FlowSpeech, with each plan's price, limits and inclusions under Pricing on this page.

Is the FlowSpeech API ready for AI agents?

FlowSpeech has a Kin Score of 42.0 out of 100 (developing) and an Agent Readiness score of 36.8 (agent-ready), scored by API Evangelist on 2026-11-13.

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