# Alternatives to Cartesia > Source: https://theagentsindex.com/cartesia/alternatives (current datasheets, evidence-ranked) Candidates share the baseline category or are previously researched peers. Requirements, preserved strengths, explicit trade-offs and research coverage decide the order; paid tier does not. ## Shortlist ### 1. ElevenLabs Agents Hosted platform for building voice and chat agents, with telephony, SDKs and a choice of LLM. **Research coverage:** 35/35 criteria **Where it improves on Cartesia:** - [Writes code: partial — ElevenLabs agents do not author code themselves; the Cursor integration lets an agent launch Cursor background agents that do, and needs a paid Cursor plan.](https://elevenlabs.io/docs/eleven-agents/customization/integrations/cursor) - [Debugs and fixes: partial — Bug fixing is delegated: the agent starts and steers a Cursor background agent, which diagnoses and lands the change; ElevenLabs itself never touches the repository.](https://elevenlabs.io/docs/eleven-agents/customization/integrations/cursor) - [Done-for-you service: partial — Self-serve software you run, but enterprises can buy ElevenLabs Forward Deployed Engineers who scope, build and stabilise the deployment; no price is published.](https://elevenlabs.io/agents/forward-deployed-engineers) **Trade-offs against Cartesia:** - [In your editor: no — The vendor enumerates its surfaces as web widgets, mobile apps, phone systems and custom integrations; no editor or IDE extension appears in that list.](https://elevenlabs.io/docs/eleven-agents/integrate/overview) [View ElevenLabs Agents](https://theagentsindex.com/elevenlabs-conversational-ai) ### 2. Vapi Developer platform for building, testing and deploying voice AI agents that make and receive phone calls. **Research coverage:** 35/35 criteria **Where it improves on Cartesia:** - [Done-for-you service: partial — You build and run the agent yourself; the Scale contract adds an embedded Vapi engineer for the go-live, not a done-for-you build.](https://vapi.ai/) - [Multi-agent: yes — Squads route one conversation across several specialised assistants with context-preserving handoffs.](https://docs.vapi.ai/quickstart/introduction) - [Open models: yes — Open-weight models reach the pipeline through Groq, Together AI, Mistral, DeepSeek and OpenRouter, or a self-hosted server.](https://vapi.ai/platform) **Trade-offs against Cartesia:** - [Seat model: no — Nothing is priced per seat: the plan table meters call minutes and concurrent lines only, and members are invited with RBAC roles.](https://vapi.ai/pricing) - [Certifications: partial — SOC 2 Type II and a HIPAA BAA sit in the Scale contract, and the plan table shows SOC2 only in that column; HIPAA mode is a $2,000/month add-on on either plan.](https://docs.vapi.ai/enterprise/plans) [View Vapi](https://theagentsindex.com/vapi) ### 3. PolyAI Enterprise platform for building voice and chat agents that resolve customer calls, priced per minute. **Research coverage:** 35/35 criteria **Where it improves on Cartesia:** - [Writes code: partial — Wren generates agent configuration and the Python tool functions that call your APIs from a description; it does not author application source code.](https://docs.poly.ai/wren/building) - [Debugs and fixes: partial — Wren diagnoses production conversations (tool calls, latency, drop-offs) and can implement the fix on a branch; the subject is agent behaviour, not application code.](https://docs.poly.ai/wren/automated-review) - [Writes tests: partial — It authors and maintains conversation simulation tests that run in CI; these are agent scenario tests, not unit tests for source code.](https://docs.poly.ai/wren/introduction) **Trade-offs against Cartesia:** - [Self-hosted: no — Runs only as PolyAI-hosted SaaS on AWS with region-specific workspaces; no on-premise or customer-cloud deployment appears anywhere in the vendor's docs or security pages.](https://poly.ai/security) - [Seat model: no — No per-seat price is published; billing tracks conversation volume, and team members are added by invitation with role-based permissions.](https://poly.ai/msa) - [Pooled budget: partial — Conversation volume draws on one account-level Subscription Volume of CX Tokens, but the Wren builder allowance is per person and not shared.](https://docs.poly.ai/wren/usage-and-limits) [View PolyAI](https://theagentsindex.com/polyai) ### 4. LiveKit Agents Open-source Python and Node.js framework for voice AI agents, with LiveKit Cloud hosting, telephony and observability. **Research coverage:** 35/35 criteria **Where it improves on Cartesia:** - [Multi-agent: yes — Multiple agents in one session via handoffs, plus a supervisor pattern where one agent keeps control and delegates to scoped tasks.](https://docs.livekit.io/agents/logic/workflows.md) - [Open models: yes — Open-weight models are the recommended default in LiveKit Inference (Gemma 4 31B, GPT OSS 120B, DeepSeek), and the Ollama plugin runs models locally.](https://docs.livekit.io/agents/models/llm/) - [Self-hosted: yes — Agents are containers you can run on your own Kubernetes; the LiveKit media server and SIP service are separately self-hostable. Self-hosted agents still meter WebRTC participant minutes if they connect to LiveKit Cloud.](https://docs.livekit.io/deploy/custom/deployments.md) **Trade-offs against Cartesia:** - [MCP server: partial — The agent is the MCP client: it consumes tools from remote HTTP or local stdio MCP servers, Python only. LiveKit does not expose a running agent as an MCP server for another agent to query.](https://docs.livekit.io/agents/logic/tools/mcp.md) - [Seat model: no — Not seat-priced. Plans are per project with usage allowances, and neither the plan cards nor the feature matrix publishes a seat count, floor or ceiling; dashboard users get admin, write or read roles.](https://docs.livekit.io/deploy/admin/quotas-and-limits.md) - [Pooled budget: partial — No per-user balances: allowances pool inside a project. Sharing one plan across projects, and quotas managed at workspace level, are Enterprise only.](https://docs.livekit.io/deploy/admin/quotas-and-limits.md) [View LiveKit Agents](https://theagentsindex.com/livekit-agents) ### 5. OmniDimension No-code platform for building voice AI agents and running them on phone, web chat, WhatsApp, email and SMS. **Research coverage:** 35/35 criteria **Where it improves on Cartesia:** - [Done-for-you service: partial — You run the software yourself from a no-code dashboard, but the terms of use offer paid professional services on request, and the Enterprise tier adds a dedicated account manager, priority onboarding and live training.](https://omnidim.io/terms-of-use) - [Multi-agent: partial — Workflows chain agent actions and can call sub-workflows, so several agents run in sequence, but the docs describe no agent-to-agent handoff or shared-state orchestration.](https://docs.omnidim.io/docs/workflows) - [Open models: yes — Open-weight families are selectable through the OpenRouter and Bedrock entries in the catalogue, so you are not confined to closed frontier models.](https://omnidim.io/pricing) **Trade-offs against Cartesia:** - [Claude: no — The pricing page publishes the full model catalogue and its alphabetical LLM list runs from Bedrock straight to Gemini with no Anthropic or Claude entry; the agent API model enum likewise names none.](https://omnidim.io/pricing) - [On the command line: partial — The only terminal-run component is the local MCP server, installed and diagnosed with npx sub-commands; no CLI exists for building agents or dialling calls on its own.](https://docs.omnidim.io/docs/mcp/local-server) - [Self-hosted: no — No self-hosted, VPC or on-premise option appears anywhere in the pricing tiers or docs; even the white-label agency product runs on the vendor's infrastructure with the customer only pointing DNS at them.](https://docs.omnidim.io/docs/omnirelay/faq) [View OmniDimension](https://theagentsindex.com/omnidimension) ### 6. Retell AI Pay-as-you-go platform for building, testing and running AI phone, chat and SMS agents. **Research coverage:** 34/35 criteria **Where it improves on Cartesia:** - [Writes tests: partial — Produces graded conversation test cases for its own agents, not software tests.](https://docs.retellai.com/general/introduction) - [Done-for-you service: partial — You run the software yourself in Retell's no-code studio; hands-on implementation by Retell's people is sold only as an Enterprise add-on, not as a managed service.](https://www.retellai.com/pricing) - [Multi-agent: yes — One call can be handed between several specialised AI agents mid-conversation, with the destination agent inheriting the full transcript, so work is split across agents rather than one monolith.](https://docs.retellai.com/build/conversation-flow/transfer-agent-node) **Trade-offs against Cartesia:** - [On the command line: no — The docs enumerate every way to drive Retell: dashboard, REST API, Node/Python SDKs and MCP server. No command-line tool is among them.](https://docs.retellai.com/general/introduction) - [Self-hosted: no — The platform runs on Retell's own infrastructure: pay-as-you-go uses shared servers and the most isolation offered is a dedicated Retell server sold as an Enterprise add-on, with no customer-infrastructure deployment documented.](https://www.retellai.com/pricing) - [Free tier: partial — You can sign up and run real calls without talking to sales, but the free allowance is a one-off $10 trial credit per email address rather than a standing free plan.](https://docs.retellai.com/accounts/billing) [View Retell AI](https://theagentsindex.com/retell-ai) ## Method Unknown data is never treated as a benefit or a trade-off. Featured placement is labelled but cannot alter recommendation order.