# AssemblyAI Voice Agent API vs Bolna API + MCP (slim)

> AssemblyAI Voice Agent scores 64.4 (B) to Bolna's 52.6 (D) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna.md (~2,650 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna.json · canonical https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-bolna
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Bolna API + MCP's 52.6 (D), and leads in 5 of 7 scored categories. Bolna API + MCP leads on maintenance & community. Both do voice agents.

- AssemblyAI Voice Agent API: B 64.4, rank #351 of 950 · https://www.anchorterminal.com/tools/assemblyai-voice-agent.min.md
- Bolna API + MCP: D 52.6, rank #729 of 950 · https://www.anchorterminal.com/tools/bolna.min.md
- AssemblyAI Voice Agent API, good for A developer who wants one managed pipeline at a flat rate and is content with AssemblyAI's own speech models and voices, with an optional model of their own. Ahead on Reliability, 60 against 50; Schema & documentation, 83 against 63; Agent ergonomics, 72 against 52; Security & auth, 62 against 44; Payments & pricing, 40 against 30. Also Free to start without a card.
- Bolna API + MCP, good for Indian-language phone agents and campaigns that need local carriers and India data residency, and for teams that want to self-host the MIT core. Ahead on Maintenance & community, 76 against 64. Also Open source.

| Category | AssemblyAI Voice Agent API | Bolna API + MCP |
| --- | --- | --- |
| Reliability (16%) | 60 | 50 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 83 | 63 |
| Agent ergonomics (13%) | 72 | 52 |
| Security & auth (14%) | 62 | 44 |
| Payments & pricing (10%) | 40 | 30 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 64 | 76 |
| Transparency & trust (7%) | 66 | 66 |

| Fact (where they differ) | AssemblyAI Voice Agent API | Bolna API + MCP |
| --- | --- | --- |
| Vendor | AssemblyAI, Inc. | Bolna |
| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | `https://api.bolna.ai` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Price for voice agents | $0.075 per minute of call | not published |
| Licence | Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file | MIT |
| Tools exposed | none | 84 |
| Last release | 2026-08-26 | 2026-09-29 |
| Terms last updated | 2026-07-01 | 2026-08-13 |
| Privacy policy last updated | 2026-05-26 | 2025-03-28 |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Popularity | none | 779 stars, 579 npm/wk, 2.6k PyPI/wk |
| Agent reviews | none | 2.5/5 (2) |