# Conversational voice-agent APIs (slim)

> 10 conversational voice agents ranked by the Anchor benchmark. Leader ElevenLabs Agents API + MCP (BB). Platforms that run a spoken conversation for you, either with one speech-to-speech model or a configurable pipeline of speech-to-text, a language model and text-to-speech. Compared on response latency, handling interruptions, tool calls, recovery after a misunderstanding and cost per completed call.

- Full: https://www.anchorterminal.com/categories/voice-agents.md (~2,800 tokens) · this version ~530 tokens · JSON https://www.anchorterminal.com/categories/voice-agents.json · canonical https://www.anchorterminal.com/categories/voice-agents
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-04

- Tools: 10 · agent-ready (BB+): 1 · accept x402: 0 · JSON: https://www.anchorterminal.com/api/v1/tools.json · by capability: https://www.anchorterminal.com/api/v1/capabilities.json
- Capabilities: voice.agent, voice.speech-to-speech, voice.pipeline, voice.tools, voice.telephony

| # | Tool | Grade | Score | Confidence | x402 | Auth | Where | Slim |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 83 | ElevenLabs Agents API + MCP | BB | 71.5 | medium | no | OAuth or key | hosted | https://www.anchorterminal.com/tools/elevenlabs-agents.min.md |
| 114 | Retell AI API + MCP | B | 69.4 | medium | no | API key | hosted | https://www.anchorterminal.com/tools/retell-ai.min.md |
| 126 | Deepgram Voice Agent API | B | 68.4 | medium | no | API key | hosted + local | https://www.anchorterminal.com/tools/deepgram-voice-agent.min.md |
| 191 | Bland AI API + MCP | B | 64.1 | medium | no | API key | hosted + local | https://www.anchorterminal.com/tools/bland-ai.min.md |
| 198 | Vapi API + MCP | B | 63.7 | medium | no | API key | hosted + local | https://www.anchorterminal.com/tools/vapi.min.md |
| 279 | Ultravox Realtime API | C | 58.6 | medium | no | API key | hosted | https://www.anchorterminal.com/tools/ultravox.min.md |
| 296 | Hume EVI (Empathic Voice Interface) | C | 57.3 | medium | no | OAuth or key | hosted | https://www.anchorterminal.com/tools/hume-evi.min.md |
| 339 | Bolna API + MCP | D | 52.9 | medium | no | API key | hosted | https://www.anchorterminal.com/tools/bolna.min.md |
| 352 | Synthflow API + MCP | D | 51.3 | medium | no | OAuth or key | hosted | https://www.anchorterminal.com/tools/synthflow.min.md |
| 383 | Vogent API | D | 47.4 | medium | no | API key | hosted | https://www.anchorterminal.com/tools/vogent.min.md |