# AssemblyAI Voice Agent API vs OpenAI Realtime API (slim)

> AssemblyAI Voice Agent scores 64.4 (B) to OpenAI Realtime's 63.3 (B) for voice agents. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime.md (~2,800 tokens) · this version ~780 tokens · JSON https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime.json · canonical https://www.anchorterminal.com/compare/assemblyai-voice-agent-vs-openai-realtime
- 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 OpenAI Realtime API's 63.3 (B), and leads in 3 of 7 scored categories. OpenAI Realtime API leads on reliability and transparency & trust. 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
- OpenAI Realtime API: B 63.3, rank #400 of 950 · https://www.anchorterminal.com/tools/openai-realtime.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 Payments & pricing, 40 against 20; Maintenance & community, 64 against 52. Also Free to start without a card.
- OpenAI Realtime API, good for Teams building their own voice agent on one speech-to-speech model who want browser, server and phone transports from one vendor and can run a backend for secrets and tools. Ahead on Reliability, 67 against 60; Transparency & trust, 71 against 66.

| Category | AssemblyAI Voice Agent API | OpenAI Realtime API |
| --- | --- | --- |
| Reliability (16%) | 60 | 67 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 83 | 84 |
| Agent ergonomics (13%) | 72 | 76 |
| Security & auth (14%) | 62 | 61 |
| Payments & pricing (10%) | 40 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 64 | 52 |
| Transparency & trust (7%) | 66 | 71 |

| Fact (where they differ) | AssemblyAI Voice Agent API | OpenAI Realtime API |
| --- | --- | --- |
| Vendor | AssemblyAI, Inc. | OpenAI |
| Hosted endpoint | `wss://agents.assemblyai.com/v1/ws` | `https://api.openai.com/v1/realtime` |
| 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 | Proprietary service. The service terms on openai.com were not read. The Agents SDK for TypeScript and the OpenAPI description are MIT |
| Last release | 2026-08-26 | 2026-07-28 |
| Terms last updated | 2026-07-01 | couldn't be read |
| Privacy policy last updated | 2026-05-26 | couldn't be read |
| Customer content may train models | yes, with an opt-out | couldn't be read |
| Terms restrict automated access | yes | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | not found in the text | couldn't be read |
| Arbitration or class-action waiver | not found in the text | couldn't be read |