Kalpa Labs website screenshot

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 APIs on the APIs.io network: Meta API, Speech API, and Usage API. Tagged areas include Company, Speech, Text to Speech, Voice, and Audio.

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

🌐 Visit website 📡 Source on GitHub
40.3/100 thin ▬ flat Agent 58/100 agent ready Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
3 APIs 1 MCP Servers
CompanySpeechText to SpeechVoiceAudioConversational AIMachine LearningArtificial Intelligence

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 40.3/100 · thin
Contract Quality 14.0 / 25
Developer Ergonomics 15.7 / 20
Commercial Clarity 0.0 / 20
Operational Transparency 0.7 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 58/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 15
MCP Server 12 / 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
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/kalpa-labs: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

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.

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

kalpa-labs-mcp.yml

MCP SERVER

Rate Limits 1

Documented rate limits and quota policies.

Kalpa Labs Rate Limits

0 limits

RATE LIMITS

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

MCPServer
MCPServer
 LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

ErrorCatalog
ErrorCatalog
 Conventions
Conventions
 Lifecycle
Lifecycle
 Conformance
Conformance
 DataModel
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)

apis.yml Raw ↑ 
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
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  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: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Speech
- Text to Speech
- Voice
- Audio
- Conversational AI
- Machine Learning
- Artificial Intelligence
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: MCPServer
  url: mcp/kalpa-labs-mcp.yml
- 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