Podcastle

Podcastle is an AI audio and podcast creation platform whose developer engine, Async, exposes a low-latency Voice API for human-like text-to-speech, a browsable voice library, and instant voice cloning from a short audio sample. The API is served from https://api.async.com and authenticated with an x-api-key header plus a version header. Transcription is a Podcastle platform feature; no standalone transcription endpoint is documented in the public Voice API.

Podcastle publishes 3 API contracts indexed on the APIs.io network, including Text to Speech API, Voices API, and 1 more. Tagged areas include Artificial Intelligence, Audio, Text-to-Speech, Voice Cloning, and Podcasts.

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

Podcastle’s developer surface includes authentication, engineering blog, documentation, and 7 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

28.2/100 thin ▬ flat Agent 20/100 agent aware Front door AI 6/6 dominant Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serveFree trial⚡ Free to try

1 published contract

Artificial Intelligence Audio Text-to-Speech Voice Cloning Podcasts

Kin Score

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

Composite quality — 28.2/100 · thin

Contract Quality 9.8 / 19

Developer Ergonomics 4.7 / 15

Access Clarity 1.2 / 15

Operational Transparency 0.8 / 10

Contract Governance 1.2 / 9

Discoverability 5.0 / 8

Regulatory Posture 1.6 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 20/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 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 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
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document

9 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 7.9 — up to +18.4 composite points
Developer Ergonomics scores 31.0 — up to +13.8 composite points
Operational Transparency scores 7.9 — up to +12.0 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/podcastle/apis.yml: open an issue on github.com/api-evangelist/podcastle 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 →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Podcasting 2.0 (open podcast namespace, measurement, hosting)	undeclared	-	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

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.

Podcastle Transcription

Transcription and speech-to-text are Podcastle platform features (multi-language transcription with speaker identification) available in the product, console, and credit-based p...

Podcastle Text to Speech API

Synthesize speech from text in batch, streaming, or with word timestamps.

Podcastle Voices API

Browse the voice library and create instant voice clones.

Open Collections 3

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

Async (Podcastle) Voice Text to Speech API

OPEN COLLECTION

Async (Podcastle) Voice Text to Speech Voices API

OPEN COLLECTION

Async (Podcastle) Voice API

OPEN COLLECTION

Podcastle API pricing

Not yet checked against Podcastle's own pricing page. Compiled by API Evangelist on 2026-06-21 from async.com/pricing; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free free	Free
Essentials subscription	—
Pro subscription	—
Teams subscription	—
Async Voice API (Pay-as-you-go) usage	—
Business enterprise	—

Plan details, limits and sources →

Rate limits

Requests Per Account: see provider documentation requests
AI Credits: per subscription tier (10 lifetime free, 450/1200/3000 monthly) credits
Transcription Hours: per subscription tier (1 lifetime free, 10/25 monthly) hours

Compiled by API Evangelist, not yet checked against Podcastle's documentation. Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Podcastle Plans Pricing

6 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Podcastle Rate Limits

3 limits

RATE LIMITS

Service Levels 1

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

Podcastle

SLA

FinOps 1

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

Podcastle Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Podcastle API Rules

58 rules · 56 errors 1 warnings 1 info

SPECTRAL

Security Posture 2

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

Podcastle Authentication

apiKey · 1 scheme

SECURITY

Podcastle Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Podcastle Agentic Access

5 operations · 4 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

Blog

Blog

LinkedIn

Website

Website

Source (apis.yml)

aid: podcastle
url: https://raw.githubusercontent.com/api-evangelist/podcastle/refs/heads/main/apis.yml
name: Podcastle
kind: company
description: Podcastle is an AI audio and podcast creation platform whose developer engine, Async, exposes a low-latency Voice
  API for human-like text-to-speech, a browsable voice library, and instant voice cloning from a short audio sample. The API
  is served from https://api.async.com and authenticated with an x-api-key header plus a version header. Transcription is
  a Podcastle platform feature; no standalone transcription endpoint is documented in the public Voice API.
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: true
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium (free trial) · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  - url: https://podcastle.ai
    status: 308
    note: declared website redirects to https://async.com/ — a different registrable domain (podcastle.ai -> async.com), possible
      rename or acquisition (probed 2026-09-03, roadmap#169)
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/podcastle.png
x-docs-platform: redoc
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
tags:
- Artificial Intelligence
- Audio
- Text-to-Speech
- Voice Cloning
- Podcasts
tags_raw:
- AI
- Audio
- Text to Speech
- Voice Cloning
- Podcasting
created: '2026-06-21'
modified: '2026-06-21'
specificationVersion: '0.23'
apis:
- aid: podcastle:transcription
  name: Podcastle Transcription
  tags:
  - Transcription
  - Speech-to-Text
  - Captions
  tags_raw:
  - Transcription
  - Speech to Text
  - Captions
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://help.podcastle.ai/en/articles/9903954-generating-and-converting-text-to-speech
  baseURL: https://api.async.com
  properties:
  - url: https://async.com/
    type: Documentation
  description: Transcription and speech-to-text are Podcastle platform features (multi-language transcription with speaker
    identification) available in the product, console, and credit-based plans. A standalone transcription endpoint is not
    documented in the public Async Voice API as of the catalog date; this entry is documented as accurately as the public
    material allows.
- aid: podcastle:podcastle-text-to-speech-api
  name: Podcastle Text to Speech API
  description: Synthesize speech from text in batch, streaming, or with word timestamps.
  humanURL: https://docs.async.com/welcome-to-async-voice-api-990330m0
  baseURL: https://api.async.com
  tags:
  - Text-to-Speech
  tags_raw:
  - Text to Speech
  properties:
  - type: OpenAPI
    url: openapi/podcastle-text-to-speech-api-openapi.yml
  - type: Documentation
    url: https://docs.async.com/text-to-speech-18760785e0
  - type: APIReference
    url: https://docs.async.com/welcome-to-async-voice-api-990330m0
  - type: Documentation
    url: https://docs.async.com/list-voices-16699698e0
  - type: Documentation
    url: https://docs.async.com/clone-voice-16699697e0
- aid: podcastle:podcastle-voices-api
  name: Podcastle Voices API
  description: Browse the voice library and create instant voice clones.
  humanURL: https://docs.async.com/welcome-to-async-voice-api-990330m0
  baseURL: https://api.async.com
  tags:
  - Voice
  tags_raw:
  - Voices
  properties:
  - type: OpenAPI
    url: openapi/podcastle-voices-api-openapi.yml
  - type: Documentation
    url: https://docs.async.com/text-to-speech-18760785e0
  - type: APIReference
    url: https://docs.async.com/welcome-to-async-voice-api-990330m0
  - type: Documentation
    url: https://docs.async.com/list-voices-16699698e0
  - type: Documentation
    url: https://docs.async.com/clone-voice-16699697e0
common:
- type: AgenticAccess
  url: agentic-access/podcastle-agentic-access.yml
- type: DomainSecurity
  url: security/podcastle-domain-security.yml
- type: Authentication
  url: authentication/podcastle-authentication.yml
- url: https://podcastle.ai/blog/feed/
  type: Blog
- type: LinkedIn
  url: https://www.linkedin.com/company/podcastle-ai
- type: Website
  url: https://podcastle.ai
- type: Documentation
  url: https://docs.async.com
- type: Plans
  url: plans/podcastle-plans-pricing.yml
- type: RateLimits
  url: rate-limits/podcastle-rate-limits.yml
- type: FinOps
  url: finops/podcastle-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Podcastle API — frequently asked questions

Does Podcastle have an API?

Yes. APIs.io lists 3 APIs from Podcastle, including Podcastle Transcription, Podcastle Text to Speech API and Podcastle Voices API.

Is there an OpenAPI specification for the Podcastle API?

Yes. APIs.io indexes 2 OpenAPI specifications for Podcastle, each linked for download from this page.

How do I authenticate with the Podcastle API?

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

How much does the Podcastle API cost?

APIs.io lists 6 pricing plans for Podcastle, with each plan's price, limits and inclusions under Pricing on this page.

Is the Podcastle API ready for AI agents?

Podcastle has a Kin Score of 28.2 out of 100 (thin) and an Agent Readiness score of 19.6 (agent-aware), scored by API Evangelist on 2026-11-06.

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