Realtime Text To Audio - Pydantic Ai

The smallest possible realtime session: send plain text from Python and hear the model speak the reply. Sending text into an OpenAI realtime session asks the model to respond right away, so there's no microphone, voice-activity detection, or manual turn-taking to manage — just [send()][pydantic_ai.realtime.RealtimeSession.send] and iterate the session's events.

Demonstrates:

realtime sessions
the text-in / audio-out path (no audio hardware required)
streaming [SpeechPartDelta][pydantic_ai.messages.SpeechPartDelta] audio and transcript deltas

The script streams the spoken reply back, prints the transcript as it arrives, and saves the audio to a .wav file you can play afterwards. It's a handy starting point for turning an existing text chatbot into one that talks, or for generating spoken snippets like a voicemail greeting.

Running the Example

The realtime model runs on gpt-realtime, so you'll need an OpenAI API key set via OPENAI_API_KEY.

With dependencies installed and environment variables set, run:

bash

python/uv-run -m pydantic_ai_examples.realtime_text_to_audio "Tell me a fun fact about octopuses."

The streamed PCM audio is saved to realtime-response.wav so you can listen to the result afterwards. If the turn completes without audio, the script raises an error and does not create an empty WAV file.

Example Code

snippet {path="/examples/pydantic_ai_examples/realtime_text_to_audio.py"}