CartesiaBetaVerified 2026-10-30

Cartesia Managed Agents

New (launched 2026-10-29): Cartesia’s end-to-end voice agent platform. It handles listening, turn-taking, interruptions, tool calls and knowledge retrieval around an LLM you choose, over WebSocket or phone. Standard rate $0.03 a minute, plus LLM tokens, plus $0.014 a minute on a Cartesia number.1

CompareDocs

PricingUSD, as published

ItemValue
List price$0.03/min + LLM2
Free tierYes

Voice agents at a standard $0.03 a minute, paid from prepaid agent dollars: Free plan $1/month (about 33 minutes), Startup $49/month, Scale $299/month includes $299 for agents. Enterprise custom.2 [Verified 2026-10-30 on https://cartesia.ai/pricing]

Telephony add-on: +$0.014 a minute when the call uses a Cartesia-provided number. The per-minute rates exclude LLM usage, which is billed separately at the chosen model’s token prices (GET /v1/agents/models lists them).5 [Verified 2026-10-30 on https://docs.cartesia.ai/pricing]

Not in the cost calculator: Billed per call minute ($0.03/min standard), plus LLM tokens and $0.014/min on a Cartesia number, which the calculator’s inputs cannot express.

LimitsPer request

LimitValue
Context windowNot published
Rate limit8–60 concurrent calls

Concurrent agent calls: Free 8, Pro 12, Startup 20, Scale 60, Enterprise custom. Cartesia-provided numbers: 1, 3, 5, 10, custom. Agents have their own concurrency pool, separate from TTS and STT.2 [Verified 2026-10-30 on https://cartesia.ai/pricing]

Batch calling queues up to 5,000 recipients and dials as capacity frees; direct outbound dialing rejects numbers beyond your concurrency limit instead of queuing.4 [Verified 2026-10-30 on https://docs.cartesia.ai/line/integrations/telephony/outbound-dialing]

Official SDKs: JavaScript/TypeScript (npm install @cartesia/cartesia-js, github.com/cartesia-ai/cartesia-js) and Python (pip install cartesia, github.com/cartesia-ai/cartesia-python). API key sent as X-API-Key.3 [Verified 2026-10-30 on https://docs.cartesia.ai/tools/client-libraries]

StatusBeta

  • Launched 2026-10-29; no beta label on the launch post or docs.1 [Verified 2026-10-30 on https://www.cartesia.ai/blog/managed-agents]
  • Ranked #1 of 30 on Artificial Analysis Speech Agent Arena (Elo 1115) and top on EVA-Bench (87.4% accuracy, 90.7% experience), per Cartesia, with GPT-5.5 as the reasoning model.1 [Vendor-reported, checked 2026-10-30 on https://www.cartesia.ai/blog/managed-agents; not reproduced by AgentAPIList]

Auth

MethodAPI key (X-API-Key)
DetailsCartesia account; agents are created in the Playground or through the API, each with an agent_id.6 [Verified 2026-10-30 on https://docs.cartesia.ai/agents/introduction]

FeaturesFrom lib/apiFeatures.js

YesNoN/ANot published
CapabilityStateNote
Free tier$1 prepaid agent use/monthYes2$1 prepaid agent use/month
Tool / function callingSystem, webhook, client toolsYesSystem, webhook, client tools
Official SDKsJS/TS and PythonYes3JS/TS and Python
BatchUnverified
Structured JSON outputUnverified
StreamingUnverified
MCP supportUnverified
Fine-tuningUnverified
Open source / self-hostUnverified
SLA publishedUnverified
EU / data residencyUnverified

Fit and safety

Good for

  • Good for production phone or app voice agents that need tools and knowledge bases with your choice of LLM.
  • A free plan exists ($1 prepaid agent usage a month) for testing.

How it works

  1. Agents API with a reusable agent_id; configure instructions, language, voice and managed LLM.
  2. Three tool kinds: system tools (built-in, e.g. end call), webhook tools (Cartesia calls your server) and client tools (your app runs them on request).
  3. Audio over a two-way WebSocket from a browser, mobile app or server, or telephony to the phone network.
  4. Knowledge bases, outbound campaigns (batches), version history and evaluations.
  5. 44 languages; mid-conversation switching between English, Spanish, Hindi, French and Japanese, with the rest “coming soon”.

Compare

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SourcesFootnotes

  1. 1Cartesia blog: Introducing Managed Agentscartesia.ai/blog/managed-agentsVerified 2026-10-30
  2. 2Cartesia pricingcartesia.ai/pricingVerified 2026-10-30
  3. 3Cartesia docs: Client librariesdocs.cartesia.ai/tools/client-librariesVerified 2026-10-30
  4. 4Cartesia docs: Outbound callingdocs.cartesia.ai/line/integrations/telephony/outbound-dialingVerified 2026-10-30
  5. 5Cartesia docs: Pricingdocs.cartesia.ai/pricingVerified 2026-10-30
  6. 6Cartesia docs: Managed Agentsdocs.cartesia.ai/agents/introductionVerified 2026-10-30