OpenAI Realtime API pricing and alternatives
OpenAI publishes prices, but doesn't say which plan includes the AI features of Realtime API. OpenAI doesn't state a free plan or trial.
What does Realtime API do?
Realtime API is OpenAI's developer API that lets a speech model answer phone calls. A business connects a phone number through a SIP trunking provider such as Twilio, accepts or rejects each incoming call, and sets the model, voice, tools and instructions. Calls can be transferred or ended through the API. Usage is billed per token.
What else should you know about Realtime API?
Realtime API is priced by usage. OpenAI doesn't state any security or compliance standard.
| Fact | As stated | Checked |
|---|---|---|
| Price | Prices published, but not the plan with the AI | Oct 17, 2026 |
| Pricing model | Usage-based | Oct 17, 2026 |
Who is Realtime API for, and what's the catch?
Suits a business with an in-house developer that wants to build its own phone agent from scratch. There is no separate fee for the API itself: tokens are billed at the chosen model's input and output rates.
The catch: token billing makes the cost of a call hard to predict, and you still need a SIP trunking provider for the number. Telnyx says its Voice AI Agents are built into the carrier network, from $0.05 per minute.
What are the alternatives to Realtime API?
Other AI voice agents to compare with Realtime API are ElevenAgents (from $6 per month), Dapta (from $99 per month) and Aircall's AI Voice Agents (from $100 per month).
| Tool | Price as stated | Free plan or trial | Compliance it states | Checked |
|---|---|---|---|---|
| ElevenAgentsElevenLabs · Vendor site | From $6 per month | Free plan | SOC 2 Type II, ISO 27001, PCI DSS, Signs a HIPAA BAA | Oct 17, 2026 |
| DaptaDapta · Vendor site | From $99 per month | Not stated | Not stated | Oct 17, 2026 |
| Aircall's AI Voice AgentsAircall · Vendor site | From $100 per month | Not stated | SOC 2 Type II, GDPR, Signs a HIPAA BAA | Oct 17, 2026 |
| Brilo AIBrilo AI · Vendor site | From $149 per month | Free plan | Not stated | Oct 17, 2026 |
| SigmaMind AISigmaMind AI · Vendor site | From $0.096 per minute | Not stated | SOC 2 (type not stated) | Oct 17, 2026 |