4 alternatives
4 sipgate flow alternatives (2026)
The closest alternatives to sipgate flow in October 2026 are LiveKit Agents, OpenAI Realtime API and Cartesia.
4 agents compared · 2 with a free plan · prices checked 2 September–24 October 2026
Reviewed by The Agents Index editorial team.
sipgate flow and its alternatives at a glance
| Agent | Best for | Starts at | Better than sipgate flow at | Checked |
|---|---|---|---|---|
| sipgate flow | On quote source | 26 September 2026 | ||
| LiveKit Agents | Engineering teams that want to own their voice-agent stack end to end, self-hosted or on LiveKit Cloud, without being locked into one vendor's API. | Free, then $50/month source | Runs autonomously, Multi-agent | 2 September 2026 |
| OpenAI Realtime API | Engineering teams building a voice agent from scratch who want to go directly to OpenAI's own speech-to-speech model (no orchestration platform, no per-minute markup) and are comfortable being single-vendor on OpenAI. | From $10/1m audio input tokens source | Multi-agent, Agent permissions | 23 October 2026 |
| Cartesia | Engineering teams that want an open-source voice-agent SDK with real LLM choice, built on speech models several rival platforms in this category already license as a component. | Free, then $5/month source | Runs autonomously, On the command line | 2 September 2026 |
| Deepgram Voice Agent API | Engineering teams that want a managed speech pipeline with real LLM-provider choice, and regulated enterprises that need a self-hosted or VPC deployment option a typical closed-source voice-agent vendor does not offer. | From $0.05/minute source | Runs autonomously, Open models | 2 September 2026 |
Shortlist
Closest alternatives to sipgate flow
The ones people open most here come first, then the closest matches. How we rank
- 01
LiveKit Agents
Open-source Python and Node.js framework for voice AI agents, with LiveKit Cloud hosting, telephony and observability.
From FreeWhy it's on this listRuns autonomously · YesAgents run as server-side workers dispatched into a live session, handling calls end to end and handing off to a human only when the flow transfers.Source ↗
Where it improves on sipgate flow
- +Multi-agent · YesMultiple agents in one session via handoffs, plus a supervisor pattern where one agent keeps control and delegates to scoped tasks.Source ↗
- +Open models · YesOpen-weight models are the recommended default in LiveKit Inference (Gemma 4 31B, GPT OSS 120B, DeepSeek), and the Ollama plugin runs models locally.Source ↗
Trade-offs against sipgate flow
- −Pooled budget · PartlyNo per-user balances: allowances pool inside a project. Sharing one plan across projects, and quotas managed at workspace level, are Enterprise only.Source ↗
- −Data residency · PartlyUS, EU and India, configurable per project, though the region pinning row on the plan matrix is No for Build and Ship, Yes from Scale. Single-tenant deployments are not offered.Source ↗
- −Certifications · PartlySOC 2 Type II active, GDPR and CCPA/CPRA compliant, EU-US DPF certified; ISO 27001 and PCI DSS still in progress, HIPAA BAAs only for Scale and Enterprise, and the security reports row is Scale and above.Source ↗
- 02
OpenAI Realtime API
Speech-to-speech API for voice agents, with tools, MCP and WebRTC or WebSocket transport.
From $10/1m audio input tokensWhy it's on this listMulti-agent · YesHandoffs between agents are a first-class part of a Realtime session, and the vendor points spoken workflows that branch across specialists at its orchestration-and-handoffs guide.Source ↗
Where it improves on sipgate flow
- +Agent permissions · YesPermissioning is explicit and developer-held: function tools exist precisely so approval checks and private system access stay in your application, while MCP tools let the API call a remote server for you.Source ↗
- +On the command line · PartlyThe platform ships an official CLI for shell-native workflows, but the documented surfaces it covers are Responses, structured outputs, images, speech and shell work, not realtime sessions.Source ↗
Trade-offs against sipgate flow
- −Claude · NoOnly OpenAI's own realtime snapshots are supported; the vendor's complete per-endpoint model inventory for /v1/realtime names six gpt-realtime models and no third-party model.Source ↗
- −Open models · NoNo open-weight option on this endpoint: the vendor's exhaustive supported-snapshot list for /v1/realtime contains only its own hosted gpt-realtime models.Source ↗
- −Model choice · PartlyYou choose which realtime snapshot a session uses, including the cheaper mini variants, but the choice is confined to OpenAI's own realtime family; the chained-pipeline alternative is where the vendor offers component swapping.Source ↗
- 03
Cartesia
Real-time speech models and a managed runtime for production phone and web voice agents.
From FreeWhy it's on this listRuns autonomously · YesA deployed agent runs a whole call unattended, handling turn-taking, interruptions and tool calls; it transfers to a human only when a configured condition matches.Source ↗
Where it improves on sipgate flow
- +On the command line · YesA `cartesia` CLI creates, deploys and manages agents, and can chat with agent logic locally.Source ↗
- +Free tier · YesA standing $0/mo Free plan, not a trial: it carries 20K credits and $1 of prepaid agent dollars every month, enough for roughly 27 minutes of text to speech, and you sign up without talking to sales. Commercial use licence and voice cloning start at the $5 Pro tier.Source ↗
Trade-offs against sipgate flow
- −Multi-agent · NoSystem tools enumerate three slots: end call, DTMF, and transfer to an E.164 phone number. An agent therefore hands off to a number, not to another Cartesia agent.Source ↗
- −Data residency · PartlyBy default api.cartesia.ai routes to the nearest endpoint; pinned regional deployments (US, EU, UK, India, Australia) are Enterprise-only.Source ↗
- 04
Deepgram Voice Agent API
One WebSocket API that runs speech-to-text, LLM orchestration and text-to-speech for real-time voice agents.
From $0.05/minuteWhy it's on this listRuns autonomously · YesThe API runs the whole listen-think-speak loop live, handling interruptions and calling functions to take action without a human in the conversation.Source ↗
Where it improves on sipgate flow
- +Open models · YesOpen-weight LLMs are listed as supported models: gpt-oss-20b through Groq, which requires you to supply the endpoint, and an NVIDIA Nemotron model that Deepgram manages. Deepgram's own speech and voice weights are not distributed.Source ↗
- +On the command line · PartlyThe dg CLI covers transcription, synthesis, text analysis and account management; its own getting-started enumeration and command reference contain no voice-agent command, while the agentic-tools page claims the CLI reaches voice agents. Both statements are recorded in notes.Source ↗
Trade-offs against sipgate flow
- −Data residency · PartlyEU and AU endpoints both serve the agent WebSocket, and Deepgram runs listen and speak in-region; managed LLM traffic is routed in-region only for OpenAI and Google in the EU, and on the AU endpoint the think step is processed outside Australia. Dedicated adds a customer-chosen AWS region.Source ↗
What to watch for
- LiveKit AgentsA framework, not a no-code or dashboard-first builder. Expect to write and deploy real code, unlike this category's more configured rivals.
- OpenAI Realtime API60-minute maximum session duration.
- CartesiaLine's voice-agent runtime cannot be self-hosted — only the underlying Sonic/Ink models can, on an Enterprise contract.
- Deepgram Voice Agent APINo dedicated free tier. A one-time $200 credit only, then usage billing from the first paid session.
Side by side
Compare sipgate flow with the shortlist
Compare alternatives to sipgate flow
The digest
Which agents actually ship. New agents and articles, by email, at most once a week.
Questions buyers ask
What are the best alternatives to sipgate flow?
LiveKit Agents, OpenAI Realtime API and Cartesia are the closest. They share the most of sipgate flow's features.
What is the cheapest alternative to sipgate flow?
LiveKit Agents and Cartesia have a free plan.
Which agents here have a free plan?
2 of the 4: LiveKit Agents and Cartesia.
When were these prices checked?
Between 2 September 2026 and 24 October 2026, each read on the maker's own pricing page.
Sources and method
Closest first: most of sipgate flow's features, then the fewest gaps. How we rank
Every price here was read on the maker's own pricing page.
- sipgate flow: flow.sipgate.io, checked 26 September 2026
- LiveKit Agents: livekit.com/pricing, checked 24 October 2026
- OpenAI Realtime API: developers.openai.com/api/docs/pricing, checked 23 October 2026
- Cartesia: cartesia.ai/pricing, checked 24 October 2026
- Deepgram Voice Agent API: deepgram.com/pricing, checked 2 September 2026
The digestFree
Which agents actually ship.
New agents and articles, by email, at most once a week.
Last issue · No. 1 · 13 October 2026Devin vs Claude Code: Which Should You Pick?
One-click unsubscribe
The Agents Index digest
The agents we added and what we wrote about them, by email, no more than once a week.
Last issue: Devin vs Claude Code: Which Should You Pick? · 13 October 2026