Cartesia

PASS consensus from 3 PASS.

One quickstart links key creation, installs WebSocket support, streams Sonic 3.6 text, receives chunks, and plays audio. One quickstart page carries the key-creation link, the environment variable, the install command, a complete runnable Python and TypeScript WebSocket script with a concrete model_id and voice ID, and a run command. Quickstart provides one clear path: get API key at play.cartesia.ai/keys, install cartesia[websockets], create client with env var, open WebSocket context with sonic-3.6, push chunks, and receive audio.

PASS consensus from 2 PASS, 1 PARTIAL.

Tables give TTS 2/3/5/15, STT 8/12/20/60, 10× TTS sockets, and 5/3-minute timeouts, contradicting the identical-values claim. One page gives per-plan TTS and STT concurrency numbers (Free 2/8 through Scale 15/60), the WebSocket ceiling at 10X the concurrency limit, and idle timeouts of 5 minutes for TTS and 3 minutes for STT; the agent-call table on the scaling page states explicitly that its matching numbers are a separate pool. One page lists all values: TTS concurrency per plan (2/3/5/15), STT concurrency per plan (8/12/20/60), WebSocket limit (10x concurrency), TTS idle timeout (5 min), STT idle timeout (3 min). Values consistent across English and Japanese pages.

PARTIAL consensus from 3 PARTIAL.

The failed /api-reference/errors fetch led to a working error page that names the cause but omits complete retry steps. The API Errors table defines concurrency_limited but links to nothing, the concurrency page is reachable only by guessing its URL, and no page in the whole corpus mentions Retry-After, backoff, or how long to wait before retrying. The error_code concurrency_limited is named and the error structure is documented. Suggested fixes exist (upgrade plan, close idle connections, use connection pools). But no step-by-step recovery path from a 429 back to a successful call, no retry-after guidance, no backoff procedure.

PARTIAL consensus from 1 PASS, 2 PARTIAL.

The guide covers the full path, but its omission claim conflicts with the creation response reference. The create-receive-verify path is complete and includes retries and deduplication, but the guide's curl authenticates with X-API-Key while the API reference and API Conventions use Authorization: Bearer, and the guide says the secret is always omitted from API responses while the reference returns it on creation. Complete create-receive-verify path documented: POST /agents/webhooks registers with url+secret, PATCH /agents/{agent_id} attaches webhook_id, events arrive with x-webhook-secret header for verification, and webhook_request_id for deduplication. API reference and observability guide are consistent.

PASS consensus from 3 PASS.

The official Python example uses Sonic 3.6 and the same request fields as the Bytes API. The Client Libraries page names the official repository and install command and routes to the quickstart, whose example matches the API reference, which accepts voice as either a plain ID string or an object with id. Official Python SDK is documented with install command. Both the quickstart and the basic example provide complete working TTS code using the same API pattern (websocket_connect, context, push, no_more_inputs, receive) that matches the WebSocket API reference.