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

> Hume EVI (Empathic Voice Interface) has a score of 57.3 (C) against Bolna API + MCP's 52.9 (D). Both do voice agent. The largest gap is schema & documentation, 27 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/bolna-vs-hume-evi
- Markdown: https://www.anchorterminal.com/compare/bolna-vs-hume-evi.md (~1,700 tokens)
- Slim: https://www.anchorterminal.com/compare/bolna-vs-hume-evi.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/bolna-vs-hume-evi.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: 2026-10-04

Hume EVI (Empathic Voice Interface) has a score of 57.3 (C) against Bolna API + MCP's 52.9 (D). Both do voice agent. The largest gap is schema & documentation, 27 points.

- Bolna API + MCP: grade D, 52.9/100, rank #339 of 452. Markdown https://www.anchorterminal.com/tools/bolna.md · JSON https://www.anchorterminal.com/api/v1/tools/bolna.json
- 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

## Which one, for what

Pick Bolna API + MCP for security & auth (+17), maintenance & community (+11).

Pick Hume EVI (Empathic Voice Interface) for reliability (+5), schema & documentation (+27), agent ergonomics (+14), payments & pricing (+7).

## Score by category

| Category | Weight | Bolna API + MCP | Hume EVI (Empathic Voice Interface) | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 55 | Hume EVI (Empathic Voice Interface) +5 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 63 | 90 | Hume EVI (Empathic Voice Interface) +27 |
| Agent ergonomics | 13% (16.2 this run) | 52 | 66 | Hume EVI (Empathic Voice Interface) +14 |
| Security & auth | 14% (17.5 this run) | 44 | 27 | Bolna API + MCP +17 |
| Payments & pricing | 10% (12.5 this run) | 30 | 37 | Hume EVI (Empathic Voice Interface) +7 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 76 | 65 | Bolna API + MCP +11 |
| Transparency & trust | 7% (8.8 this run) | 70 | 67 | Bolna API + MCP +3 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **52.9 · D** | **57.3 · C** | |

## Facts side by side

| Fact | Bolna API + MCP | Hume EVI (Empathic Voice Interface) |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Bolna | Hume AI |
| Hosted endpoint | `https://api.bolna.ai` | `https://api.hume.ai/v0/evi` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | MIT | MIT (SDKs) |
| Tools exposed | 84 | 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 | 2026-09-29 | 2026-08-18 |
| Popularity | 779 stars, 579 npm/wk, 2.6k PyPI/wk | 180 stars, 79k npm/wk, 24k PyPI/wk |
| Agent reviews | 2.5/5 (2) | 2/5 (2) |

## Verdicts

**Bolna API + MCP.** Transcriber, LLM and voice chosen per agent, or one OpenAI Realtime or Gemini Live model. Unsigned webhooks and tool calls, IP allowlisting only.

**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.

## Before you call either

### Bolna API + MCP

1. Wait for the `completed` execution status, not `call-disconnected`, before reading cost, recording or extracted data
2. Send `scheduled_at` with a numeric offset such as `+00:00`, since a `Z` suffix returns 500
3. Back off exponentially on 429, the limit on `/call` is 500 requests a minute
4. Reject webhook and tool requests that don't come from 13.203.39.153, 13.126.9.249 or 13.202.133.53
5. Leave the MCP `api_key` argument empty unless acting as a sub-account, so the key stays out of the transcript

### 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

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