/v1/audio/speech is OpenAI-SDK compatible: same body shape, same response shape (binary audio with Content-Type per format). Supports full or streaming responses and respects org-level ZDR flags.
Syntax
Content-Type indicates the format.
Output formats
Real-time streaming
Passstream: true to receive audio in chunks as the model generates it (lower perceptual latency):
Tone instructions (gpt-4o-mini-tts)
Theopenai/gpt-4o-mini-tts model accepts an instructions field with style prompting:
Available models
Pricing structure
TTS models are charged per characters of synthesized text, not tokens or seconds. This mirrors provider pricing and makes cost predictable: 1000 characters ≈ 150 words regardless of audio duration. Geek Hub applies the standard +5% markup.ZDR pre-flight
If your org requires ZDR for the TTS model’s group, or if the request includeszdr: true, the gateway verifies before processing. Unverified → HTTP 422 with alternative models.
See Zero Data Retention.