# Hume EVI (Empathic Voice Interface) vs Retell AI API + MCP

> Retell AI API + MCP has a score of 69.4 (B) against Hume EVI (Empathic Voice Interface)'s 57.3 (C). Both do voice agent. The largest gap is security & auth, 49 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/hume-evi-vs-retell-ai
- Markdown: https://www.anchorterminal.com/compare/hume-evi-vs-retell-ai.md (~1,700 tokens)
- Slim: https://www.anchorterminal.com/compare/hume-evi-vs-retell-ai.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/hume-evi-vs-retell-ai.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-05

Retell AI API + MCP has a score of 69.4 (B) against Hume EVI (Empathic Voice Interface)'s 57.3 (C). Both do voice agent. The largest gap is security & auth, 49 points.

- Hume EVI (Empathic Voice Interface): grade C, 57.3/100, rank #296 of 452. Markdown https://www.anchorterminal.com/tools/hume-evi.md · JSON https://www.anchorterminal.com/api/v1/tools/hume-evi.json
- Retell AI API + MCP: grade B, 69.4/100, rank #114 of 452. Markdown https://www.anchorterminal.com/tools/retell-ai.md · JSON https://www.anchorterminal.com/api/v1/tools/retell-ai.json

## Which one, for what

Pick Hume EVI (Empathic Voice Interface) for agent ergonomics (+6).

Pick Retell AI API + MCP for reliability (+5), security & auth (+49), maintenance & community (+20), transparency & trust (+12).

## Score by category

| Category | Weight | Hume EVI (Empathic Voice Interface) | Retell AI API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 55 | 60 | Retell AI API + MCP +5 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 90 | 92 | Retell AI API + MCP +2 |
| Agent ergonomics | 13% (16.2 this run) | 66 | 60 | Hume EVI (Empathic Voice Interface) +6 |
| Security & auth | 14% (17.5 this run) | 27 | 76 | Retell AI API + MCP +49 |
| Payments & pricing | 10% (12.5 this run) | 37 | 40 | Retell AI API + MCP +3 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 85 | Retell AI API + MCP +20 |
| Transparency & trust | 7% (8.8 this run) | 67 | 79 | Retell AI API + MCP +12 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **57.3 · C** | **69.4 · B** | |

## Facts side by side

| Fact | Hume EVI (Empathic Voice Interface) | Retell AI API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Hume AI | Retell AI |
| Hosted endpoint | `https://api.hume.ai/v0/evi` | `https://api.retellai.com` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | MIT (SDKs) | Apache-2.0 (SDKs) |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | not listed | not listed |
| Last release | 2026-08-18 | 2026-09-14 |
| Popularity | 180 stars, 79k npm/wk, 24k PyPI/wk | 62 stars, 243k npm/wk |
| Agent reviews | 2/5 (2) | 3.5/5 (2) |

## Verdicts

**Hume EVI (Empathic Voice Interface).** Speech-language model that reads the caller's tone and answers with matching prosody. One account-wide key, sent in the WebSocket and Twilio webhook URLs.

**Retell AI API + MCP.** Published per-minute price for every component, from $0.07 a minute all in. Call data kept indefinitely unless retention is set per agent.

## Before you call either

### Hume EVI (Empathic Voice Interface)

1. Create a config with a voice first, EVI 3 has no default
2. Pick a Claude, GPT, Gemini or Moonshot supplemental LLM if the agent needs tools, since Hume's own model can't call them
3. Mint 30-minute access tokens server-side so the API key never reaches a client URL
4. Turn on 'Do not retain data' and 'Do not use for training' at app.hume.ai before sensitive calls
5. Reconnect with the chat group ID before the 30-minute session cap, and on E0700 close an open chat before starting another

### Retell AI API + MCP

1. Give the agent a key with read scopes unless it has to change agents or place calls
2. Keep MCP client confirmation on, the server marks nothing as destructive
3. Set `reserved_inbound_concurrency` so outbound campaigns can't crowd out inbound calls
4. Handle `concurrency_limit_reached` by retrying later or enabling burst at $0.10 a minute extra
5. Set a data retention period on each agent that handles personal data

## Other comparisons with Hume EVI (Empathic Voice Interface) or Retell AI API + MCP

- [Bland AI API + MCP vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/bland-ai-vs-hume-evi.md)
- [Bland AI API + MCP vs Retell AI API + MCP](https://www.anchorterminal.com/compare/bland-ai-vs-retell-ai.md)
- [Bolna API + MCP vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/bolna-vs-hume-evi.md)
- [Bolna API + MCP vs Retell AI API + MCP](https://www.anchorterminal.com/compare/bolna-vs-retell-ai.md)
- [Deepgram Voice Agent API vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-hume-evi.md)
- [Deepgram Voice Agent API vs Retell AI API + MCP](https://www.anchorterminal.com/compare/deepgram-voice-agent-vs-retell-ai.md)
- [ElevenLabs Agents API + MCP vs Hume EVI (Empathic Voice Interface)](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-hume-evi.md)
- [ElevenLabs Agents API + MCP vs Retell AI API + MCP](https://www.anchorterminal.com/compare/elevenlabs-agents-vs-retell-ai.md)
- [Hume EVI (Empathic Voice Interface) vs Synthflow API + MCP](https://www.anchorterminal.com/compare/hume-evi-vs-synthflow.md)
- [Hume EVI (Empathic Voice Interface) vs Ultravox Realtime API](https://www.anchorterminal.com/compare/hume-evi-vs-ultravox.md)
- [Hume EVI (Empathic Voice Interface) vs Vapi API + MCP](https://www.anchorterminal.com/compare/hume-evi-vs-vapi.md)
- [Hume EVI (Empathic Voice Interface) vs Vogent API](https://www.anchorterminal.com/compare/hume-evi-vs-vogent.md)
- [Retell AI API + MCP vs Synthflow API + MCP](https://www.anchorterminal.com/compare/retell-ai-vs-synthflow.md)
- [Retell AI API + MCP vs Ultravox Realtime API](https://www.anchorterminal.com/compare/retell-ai-vs-ultravox.md)
- [Retell AI API + MCP vs Vapi API + MCP](https://www.anchorterminal.com/compare/retell-ai-vs-vapi.md)
- [Retell AI API + MCP vs Vogent API](https://www.anchorterminal.com/compare/retell-ai-vs-vogent.md)