Skip to main content
Endpoint /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

Response is binary audio directly (not JSON). Content-Type indicates the format.

Output formats

Real-time streaming

Pass stream: true to receive audio in chunks as the model generates it (lower perceptual latency):

Tone instructions (gpt-4o-mini-tts)

The openai/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 includes zdr: true, the gateway verifies before processing. Unverified → HTTP 422 with alternative models. See Zero Data Retention.