Cartesia Agent Skill

Cartesia

Purpose

Generate spoken audio from text with Cartesia's Sonic models (40+ languages) and browse the Cartesia voice library. Reach for this when the user wants narration, voiceovers, or spoken-audio files produced from a script.

Tooling

All commands go through bin/cartesia.py. Every request automatically sends the required date header Cartesia-Version: 2026-08-14.

bin/cartesia.py auth
# {"ok": true, "voices": 60} on success

bin/cartesia.py voices
# list available voices (id, name, language)

bin/cartesia.py voice-get --id <VOICE_ID>
# details for a single voice

bin/cartesia.py tts --text "Hello world" --voice-id <VOICE_ID> --out narration.wav
# synthesize speech to a local WAV file; prints the saved path

bin/cartesia.py tts --text "Bonjour le monde" --voice-id <VOICE_ID> \
    --language fr --model-id sonic-3 --out fr.wav

Notes:

• tts returns audio binary. The CLI writes it to --out (default cartesia-output.wav) and prints the resulting path.
• Streaming TTS (POST /tts/sse) and the WebSocket TTS/STT surfaces are real-time and outside CLI scope.

Auth

• Provider id: cartesia (credential is collected as custom.cartesia)
• Collection: Cartesia API key (sk_car_...) via the secure credential flow (credentials.request_api_access); create one at play.cartesia.ai/keys
• Allowed hosts: api.cartesia.ai
• Connect placement: bearer_header (the key goes in Authorization: Bearer <key>)
• The API also requires the date header Cartesia-Version: 2026-08-14 on every request; the CLI sends it for you.
• Status check: bin/cartesia.py auth

Operating Rules

• TTS synthesis is credit-metered. Every tts call spends Cartesia credits, so synthesize only what the user asked for and batch long scripts into as few calls as possible.
• Voice creation and voice cloning are confirmation-gated: confirm with the user before creating or cloning any voice. This draft CLI does not ship a clone command; use the Cartesia dashboard or SDK for cloning.
• Never use API keys in client-side code. The connector only ever handles the surrogate, never the raw key.
• The CLI pins Cartesia-Version: 2026-08-14. Treat a version bump like a dependency upgrade and do not change the date casually.

Files

• SKILL.md
• bin/cartesia.py

Maturity

🧪 Draft: written from Cartesia's public API docs with header and paths cross-checked against official docs at build time; not yet live-tested end-to-end. Voice create/clone and pronunciation dictionaries are not yet in the CLI.