Kalpa Labs

Kalpa Labs is a San Francisco audio-research lab (Y Combinator Fall 2025) building generalist speech models that unify text-to-speech, multi-speaker conversation, voice cloning, and speech-in / speech-out reasoning behind one API — steerable with natural instructions and in-context learning the way a large language model is. Their Kalpa Speech API exposes stable public model ids over a clean REST interface: POST /v1/tts turns text into 24 kHz WAV audio, POST /v1/converse completes the open turn of a conversation (authored speech or contextual TTS), and a stateful WebSocket streams multi-speaker sessions. The developer surface ships a committed OpenAPI 3.1 contract, an AsyncAPI 3.0 WebSocket protocol, docs with a markdown twin per page, an llms.txt, and a browser Studio playground. Founded by Prashant Shishodia and Gautam Jha.

Kalpa Labs publishes 3 API contracts indexed on the APIs.io network: Meta API, Speech API, and Usage API. Tagged areas include Company, Speech, Text-to-Speech, Voice, and Audio.

The Kalpa Labs catalog on APIs.io includes 1 Spectral governance ruleset.

Kalpa Labs’ developer surface includes documentation, API reference, getting-started guide, sandbox, support, authentication, and 17 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

36.3/100 thin ▬ flat Agent 25/100 agent aware Front door AI 1/6 silent Heartbeat 100/100 alive Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 published contract 2 Agent Skills

Company Speech Text-to-Speech Voice Audio Conversational AI Machine Learning Artificial Intelligence Real-Time

Kin Score

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

Composite quality — 36.3/100 · thin

Contract Quality 10.0 / 19

Developer Ergonomics 10.6 / 15

Access Clarity 0.0 / 15

Operational Transparency 0.3 / 10

Contract Governance 1.6 / 9

Discoverability 5.5 / 8

Regulatory Posture 2.3 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 25/100 · 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 0 / 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 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/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/kalpa-labs/"><img src="https://apis.io/badge/kalpa-labs/card.svg" alt="Kalpa Labs on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

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
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)
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 0.0 — up to +20.0 composite points
Operational Transparency scores 2.6 — up to +12.7 composite points
Contract Quality scores 53.5 — up to +11.6 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/kalpa-labs/apis.yml: open an issue on github.com/api-evangelist/kalpa-labs 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
Hugging Face Hub Organisations	builds-on	17.2 (thin)	-	1

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.

Kalpa Labs Meta API

Health checks and capability discovery.

Kalpa Labs Speech API

Text-to-speech and conversational generation.

Kalpa Labs Usage API

Per-key usage and metering.

Open Collections 3

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

Kalpa Speech Meta API

OPEN COLLECTION

Kalpa Meta Speech API

OPEN COLLECTION

Kalpa Speech Meta Usage API

OPEN COLLECTION

Agent Skills 2

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

Kalpa conversation completion

AGENT SKILL

Kalpa text-to-speech

AGENT SKILL

Rate Limits 1

Documented rate limits and quota policies.

Kalpa Labs Rate Limits

0 limits

RATE LIMITS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Kalpa Labs API Rules

62 rules · 56 errors 1 warnings 5 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.

Kalpa Labs Openapi Overlay

2 actions · update · kalpa-labs-openapi-original.json

DERIVED

Security Posture 2

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

Kalpa Labs Authentication

apiKey · 1 scheme

SECURITY

Kalpa Labs Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Sandbox

Sandbox

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

AsyncAPI

AsyncAPI

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

ErrorCatalog

Conventions

Lifecycle

Conformance

DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

Support

Support

RateLimits

RateLimits

Company 1

The organization behind the API

Website

Website

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: kalpa-labs
name: Kalpa Labs
description: 'Kalpa Labs is a San Francisco audio-research lab (Y Combinator Fall 2025) building generalist speech models
  that unify text-to-speech, multi-speaker conversation, voice cloning, and speech-in / speech-out reasoning behind one API
  — steerable with natural instructions and in-context learning the way a large language model is. Their Kalpa Speech API
  exposes stable public model ids over a clean REST interface: POST /v1/tts turns text into 24 kHz WAV audio, POST /v1/converse
  completes the open turn of a conversation (authored speech or contextual TTS), and a stateful WebSocket streams multi-speaker
  sessions. The developer surface ships a committed OpenAPI 3.1 contract, an AsyncAPI 3.0 WebSocket protocol, docs with a
  markdown twin per page, an llms.txt, and a browser Studio playground. Founded by Prashant Shishodia and Gautam Jha.'
url: https://raw.githubusercontent.com/api-evangelist/kalpa-labs/refs/heads/main/apis.yml
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - rate-limits
  - security
  generated: '2026-11-06'
  method: derived
image: https://kalpalabs.ai/og.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- y-combinator
- nexus-venture-partners
- n1
x-tier: active
x-tier-reason: enriched
x-location: San Francisco, CA
x-yc-batch: F25
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Speech
- Text-to-Speech
- Voice
- Audio
- Conversational AI
- Machine Learning
- Artificial Intelligence
- Real-Time
tags_raw:
- Company
- Speech
- Text to Speech
- Voice
- Audio
- Conversational AI
- Machine Learning
- Artificial Intelligence
- Machine-Learning
- Real-Time
apis:
- aid: kalpa-labs:kalpa-labs-meta-api
  name: Kalpa Labs Meta API
  description: Health checks and capability discovery.
  humanURL: https://docs.kalpalabs.ai
  baseURL: https://api.kalpalabs.ai
  tags:
  - Meta
  properties:
  - type: OpenAPI
    url: openapi/kalpa-labs-meta-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/kalpa-labs-converse-stream-asyncapi.json
- aid: kalpa-labs:kalpa-labs-speech-api
  name: Kalpa Labs Speech API
  description: Text-to-speech and conversational generation.
  humanURL: https://docs.kalpalabs.ai
  baseURL: https://api.kalpalabs.ai
  tags:
  - Speech
  properties:
  - type: OpenAPI
    url: openapi/kalpa-labs-speech-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/kalpa-labs-converse-stream-asyncapi.json
- aid: kalpa-labs:kalpa-labs-usage-api
  name: Kalpa Labs Usage API
  description: Per-key usage and metering.
  humanURL: https://docs.kalpalabs.ai
  baseURL: https://api.kalpalabs.ai
  tags:
  - Usage
  properties:
  - type: OpenAPI
    url: openapi/kalpa-labs-usage-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/kalpa-labs-converse-stream-asyncapi.json
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://kalpalabs.ai
- type: DeveloperPortal
  url: https://docs.kalpalabs.ai
- type: Documentation
  url: https://docs.kalpalabs.ai
- type: APIReference
  url: https://docs.kalpalabs.ai/reference
- type: GettingStarted
  url: https://docs.kalpalabs.ai/quickstart
- type: Sandbox
  url: https://studio.kalpalabs.ai
- type: GitHubOrganization
  url: https://github.com/kalpalabs
- type: Support
  url: mailto:hello@kalpalabs.ai
- type: Authentication
  url: authentication/kalpa-labs-authentication.yml
- type: DomainSecurity
  url: security/kalpa-labs-domain-security.yml
- type: ErrorCatalog
  url: errors/kalpa-labs-problem-types.yml
- type: Conventions
  url: conventions/kalpa-labs-conventions.yml
- type: RateLimits
  url: rate-limits/kalpa-labs-rate-limits.yml
- type: Lifecycle
  url: lifecycle/kalpa-labs-lifecycle.yml
- type: X-MCPServerCandidate
  url: mcp/kalpa-labs-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/kalpa-labs-llms.txt
- type: Overlay
  url: overlays/kalpa-labs-openapi-overlay.yaml
- type: Conformance
  url: conformance/kalpa-labs-conformance.yml
- type: DataModel
  url: data-model/kalpa-labs-data-model.yml
- type: Packages
  url: packages/kalpa-labs-packages.yml
- type: SDKs
  url: packages/kalpa-labs-packages.yml
- type: AsyncAPI
  url: asyncapi/kalpa-labs-converse-stream-asyncapi.json
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

Kalpa Labs API — frequently asked questions

Does Kalpa Labs have an API?

Yes. APIs.io lists 3 APIs from Kalpa Labs, including Kalpa Labs Meta API, Kalpa Labs Speech API and Kalpa Labs Usage API.

Is there an OpenAPI specification for the Kalpa Labs API?

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

How do I authenticate with the Kalpa Labs API?

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

Is the Kalpa Labs API ready for AI agents?

Kalpa Labs has a Kin Score of 36.3 out of 100 (thin) and an Agent Readiness score of 25.3 (agent-aware), scored by API Evangelist on 2026-11-06.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/kalpa-labs"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/kalpa-labs/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/kalpa-labs/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.