Cartesia
Cartesia builds real-time voice AI - the Sonic family of text-to-speech models, Ink speech-to-text models, and a Voice Agents platform for building and deploying telephone and web voice agents. The core generation surface is exposed both as REST (bytes and Server-Sent Events) and as a low-latency, bidirectional WebSocket protocol at wss://api.cartesia.ai for streaming TTS and STT with multiplexed contexts, word/phoneme timestamps, and mid-stream flush and cancel.
Cartesia publishes 21 APIs on the APIs.io network, including TTS WebSocket API, STT WebSocket API, Agents API, and 18 more. Tagged areas include AI, Voice AI, Text to Speech, Speech to Text, and Realtime.
The Cartesia catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.
Cartesia’s developer surface includes authentication, engineering blog, documentation, and 8 more developer resources.
Kin Score
APIs 21
Individual APIs this provider publishes, each with its own machine-readable definition.
Cartesia TTS WebSocket API
Bidirectional, multiplexed WebSocket at wss://api.cartesia.ai/tts/websocket for realtime speech generation. Clients send JSON generation requests keyed by a context_id (continui...
Cartesia STT WebSocket API
Realtime transcription over WebSocket at wss://api.cartesia.ai/stt/websocket. Clients stream raw binary audio in 100ms chunks and issue finalize/close text commands; the server ...
Cartesia Agents API
Voice agent configuration and public templates.
Cartesia API Keys API
Standard API key metadata.
Cartesia Auth API
Short-lived, scoped access token generation.
Cartesia Calls API
Outbound call placement, batching, and history.
Cartesia Datasets API
Audio/text collections used to build custom fine-tunes and voices.
Cartesia Deployments API
Agent deployment inspection.
Cartesia Infill API
Generate audio that smoothly connects two existing audio segments.
Cartesia Knowledge Base API
Documents and folders used by agents.
Cartesia Metrics API
LLM-as-a-judge quality metrics for agents.
Cartesia Phone Numbers API
Telephony number provisioning and import.
Cartesia Pronunciation Dictionaries API
Custom pronunciation overrides referenced by TTS requests.
Cartesia Providers API
Linked telephony provider accounts.
Cartesia Speech-to-Text API
Batch transcription of an audio file of any length.
Cartesia Status API
API health and version.
Cartesia Text-to-Speech API
Single-shot and streamed speech generation over plain HTTP.
Cartesia Usage API
Credit and agent usage reporting.
Cartesia Voice Changer API
Transform speech into a different target voice.
Cartesia Voices API
Voice catalog management and voice cloning.
Cartesia Webhooks API
Webhook endpoint registration.
Scroll for all 21
Open Collections 1
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
Cartesia API
OPEN COLLECTIONPricing Plans 1
Published pricing tiers and plan structures.
Rate Limits 1
Documented rate limits and quota policies.
Cartesia Ai Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals for API financial operations.
Cartesia Ai Finops
FINOPSEvent Specifications 1
AsyncAPI definitions for this provider's event-driven and streaming APIs.
Cartesia Realtime WebSocket API (TTS + STT)
AsyncAPI 2.6 description of Cartesia's **documented public WebSocket API**. Unlike most providers in this catalog, Cartesia publishes a real, bidirectional WebSocket protocol - ...
ASYNCAPISpectral Rules 1
Spectral governance rulesets for linting and validating these APIs.
Cartesia API Rules
SPECTRALSecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
Recommended x-agentic-access execution contracts for AI agents.
Resources
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Source (apis.yml)
This is an independent, third-party profile of Cartesia, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
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