Cartesia Line
Managed platform for building and deploying low-latency voice agents with custom reasoning and Cartesia speech models.
- Starting price
- Quote-based
- Setup
- Developer build
- Try it
- Self-serve trial
- Free to start
- Free plan
Use the workspace to examine speech models and API access.
The finished agent's reasoning, integrations and total cost still need testing.
At a glance
Calls & telephony
- DetailCalls
Inbound & outbound
- SupportedHuman handoff
Yes
- SupportedPhone numbers included
Yes
- SupportedBring your own carrier
Yes
- SupportedSIP trunking
Yes
Cartesia US numbers, import Twilio numbers, or SIP carrier numbers
Trust & access
- With conditionsHIPAA
Enterprise plans
BAAs on Enterprise plan; HIPAA-eligible
- SupportedSOC 2
Type II
- SupportedGDPR
Yes
GDPR compliance announced for platform
- DetailLanguages
44 languages (Sonic TTS)
- SupportedFree to start
Free plan
Free plan: 20K credits and $1 agent minutes
- SupportedDeveloper API
Yes
Morak scorecard
How we score →- Ease of setupDeveloper build
Expect developers to build call logic, integrations and deployment.
- Pricing transparencyQuote only
Pricing is quoted by sales; no list price is published.
- Try before you buyFree plan
An ongoing free plan lets you test with real calls or content.
- Call & telephony controlFull control
Documented: inbound, outbound, human handoff, phone numbers, bring-your-own carrier and SIP.
- Compliance readinessStrong
Published: SOC 2 Type II, GDPR and HIPAA on enterprise plans.
- Integration coverage1 of 4 covered
Connects to automation or API. Not listed: phone system, customer records (CRM, EHR or POS) and calendar.
Typical score among voice agent platforms
Deploy voice agents with custom reasoning
What you get
Build a voice experience with managed deployment and configurable reasoning.
What to account for
Engineering work and full-stack costs remain part of adoption. Test the completed agent, not only the underlying speech model.
Best for
- Low-latency voice agents
- Custom reasoning
- Managed agent deployment
- Teams using Cartesia speech models
Not a fit for
- Buyers wanting a finished receptionist
- Teams needing public all-in agent pricing
- Projects without engineering support
What the platform provides
- Agent runtime
- Real-time audio orchestration, deployment, observability and an agent builder around Cartesia's speech models.
- Customization
- Connect an LLM, call external APIs, deploy custom code and manage agent versions in the runtime.
Connections & compatibility
AI models & voice
- Cartesia Ink
- Cartesia Sonic
- Custom LLMs
Automation & APIs
- Custom API
- CLI
- Webhooks
Data access & permissions
What an agent built on Cartesia Line can touch once deployed. These are the first questions a security review will ask.
- Reads customer dataYes
- Writes to your systemsYes
- Sends messagesYes
- Triggers workflowsYes
- Records callsYes
- Needs API keysYes
- Human approval stepYes
Use encrypted environment variables, restrict external API tools, obtain voice and recording consent, separate deployment environments, and verify region, retention, data residency, and voice-cloning controls.
Pricing & terms
Cartesia publishes model plans but a clear all-in Line agent-minute rate was not confirmed. Request or verify current Line, speech, deployment, concurrency, and telephony pricing before procurement.
Before committing
Fail a tool call and inspect the logs and rollback path. Confirm the full model, telephony and deployment cost for that configuration.
How it compares
Side by side with two alternatives buyers weigh against it, on the same facts and scorecard.
| Detail | Cartesia Line This productManaged platform for building and deploying low-latency voice agents with custom reasoning and Cartesia speech models. | Similar product Conversational voice platform focused on expressive speech, realtime interaction, and prosody-aware responses. | Similar product ElevenLabs' platform for building voice and chat agents (formerly Conversational AI), useful for teams prioritizing voice quality. |
|---|---|---|---|
| Starting price | Quote-based | From $0.04/min | From $6/mo |
| Free to start | Free plan | Free plan | Free plan |
| Calls | Inbound & outbound | Not a phone product | Inbound & outbound |
| HIPAA | Enterprise plans | Enterprise plans | Enterprise plans |
| Morak scorecard How we score | |||
| Ease of setup | 2 of 5, Developer build | 2 of 5, Developer build | 2 of 5, Developer build |
| Pricing transparency | 1 of 5, Quote only | 5 of 5, Rates published | 4 of 5, Starting price |
| Try before you buy | 5 of 5, Free plan | 5 of 5, Free plan | 5 of 5, Free plan |
| Call & telephony control | 5 of 5, Full control | — | 4 of 5, Broad |
| Compliance readiness | 5 of 5, Strong | 5 of 5, Strong | 5 of 5, Strong |
| Integration coverage | 2 of 5, 1 of 4 covered | 2 of 5, 1 of 3 covered | 3 of 5, 2 of 4 covered |