# Introducing the Realtime API

*Source* · `src-openai-2024-realtime-api` · status: **n/a**

| field | value |
|---|---|
| kind | Technical report / blog |
| authors | OpenAI |
| venue | OpenAI blog |
| date | 2024-10-01 |
| url | https://openai.com/index/introducing-the-realtime-api/ |
| accessed | 2026-10-24 |

## Notes

Speech-to-speech over a persistent WebSocket with GPT-4o (gpt-4o-realtime-preview), automatic interruption handling, function calling. Audio $100 and $200 per 1M input and output tokens, about $0.06 per minute in and $0.24 per minute out; text $5 and $20. Later updates through general availability in August 2025.

## Backlinks (computed)

**cited by:** [Realtime speech-to-speech and expressive TTS for characters](../technique/realtime-voice-models.md)

## Citation

OpenAI (2024-10-01). *Introducing the Realtime API*. OpenAI blog https://openai.com/index/introducing-the-realtime-api/

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Provenance: created in run `2026-10-24-techniques-llm-agents`.