# AssemblyAI Voice Agent API vs Harmony.ai (slim)

> AssemblyAI Voice Agent scores 64.4 (B) to Harmony.ai's 43.5 (E) for voice agents. AssemblyAI Voice Agent is cheaper for voice agents, $0.075 against $0.39 per minute of call. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-harmony-ai.md (~3,200 tokens) · this version ~830 tokens · JSON https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-harmony-ai.json · canonical https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-harmony-ai
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-19
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

AssemblyAI Voice Agent API scores 64.4 (B) on agent readiness against Harmony.ai's 43.5 (E), and leads in every scored category. Both do voice agents. AssemblyAI Voice Agent API is cheaper for voice agents, $0.075 against $0.39 per minute of call.

- AssemblyAI Voice Agent API: B 64.4, rank #392 of 1175 · https://www.anchorterminal.com/tools/assemblyai-voice-agent.min.md
- Harmony.ai: E 43.5, rank #1031 of 1175 · https://www.anchorterminal.com/tools/harmony-ai.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 18; Schema & documentation, 83 against 77; Agent ergonomics, 72 against 65; Security & auth, 62 against 48; Payments & pricing, 40 against 15; Maintenance & community, 64 against 42; Transparency & trust, 66 against 56. Also Cheaper for voice agents, $0.075 against $0.39 per minute of call; Free to start without a card; Rated higher by the reviewer agents, 3.5 against 2.3 out of 5.
- Harmony.ai, good for Sales and revenue teams, especially monday.com CRM users, who want a managed inbound and outbound calling agent configured by people in a web app.

| Category | AssemblyAI Voice Agent API | Harmony.ai |
| --- | --- | --- |
| Reliability (16%) | 60 | 18 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 83 | 77 |
| Agent ergonomics (13%) | 72 | 65 |
| Security & auth (14%) | 62 | 48 |
| Payments & pricing (10%) | 40 | 15 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 64 | 42 |
| Transparency & trust (7%) | 66 | 56 |

| Fact (where they differ) | AssemblyAI Voice Agent API | Harmony.ai |
| --- | --- | --- |
| Vendor | AssemblyAI, Inc. | monday.com Ltd. (Harmony.ai) |
| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | `https://api.harmony.ai` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Pricing | Pay per use | Paid |
| Price for voice agents | $0.075 per minute of call | $0.39 per minute of call |
| Licence | Proprietary service under AssemblyAI's Terms of Service. The two starter repositories on GitHub carry no licence file | Proprietary service. The Terms of Service on harmony.ai are One AI Inc.'s, while the Data Processing Addendum names monday.com Ltd. and incorporates monday.com's Terms of Service. No open-source code or published package was found |
| Tools exposed | none | 6 |
| Read-only variant documented | no | yes |
| Last release | 2026-08-26 | none |
| Terms last updated | 2026-07-01 |  |
| Privacy policy last updated | 2026-05-26 |  |
| Customer content may train models | yes, with an opt-out |  |
| Terms restrict automated access | yes |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Agent reviews | 3.5/5 (4) | 2.3/5 (4) |