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Documentation Index

Fetch the complete documentation index at: https://docs.getpatter.com/llms.txt

Use this file to discover all available pages before exploring further.

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OpenAI TTS

OpenAITTS is a Patter TTSProvider backed by OpenAI’s POST /v1/audio/speech endpoint. It streams 24 kHz PCM from OpenAI and resamples it to 16 kHz or 8 kHz on the fly so the telephony output path can forward bytes without an additional resample stage. No vendor SDK required.

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Install

openai-tts ships in the base install — no extra needed. 
pip install getpatter
On Python 3.13+ install audioop-lts for the in-process 24 kHz → 16 kHz (or 8 kHz) resampler. It’s pinned in getpatter’s base dependencies.

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Usage

Use the namespaced import (getpatter.tts.openai) or the flat alias (getpatter.OpenAITTS). Both auto-resolve OPENAI_API_KEY from the environment when api_key= is omitted.
# Namespaced import
from getpatter.tts import openai

tts = openai.TTS()                                        # reads OPENAI_API_KEY
tts = openai.TTS(api_key="sk-...", voice="nova", model="tts-1-hd")

# Flat alias (equivalent)
from getpatter import OpenAITTS

tts = OpenAITTS()
In an agent: 
import asyncio
from getpatter import Patter, Twilio, DeepgramSTT, OpenAITTS

phone = Patter(carrier=Twilio(), phone_number="+15550001234")

agent = phone.agent(
    stt=DeepgramSTT(),                                    # DEEPGRAM_API_KEY from env
    tts=OpenAITTS(voice="nova"),                          # OPENAI_API_KEY from env
    system_prompt="You are a helpful assistant.",
)

asyncio.run(phone.serve(agent))

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Models and rates

OpenAI TTS bills per 1,000 characters synthesized. Per-model rates (defaults from getpatter.pricing):
ModelRate / 1k charsNotes
tts-1 (default)$0.015Fast, telephony-friendly.
tts-1-hd$0.030Higher fidelity — heavier.
gpt-4o-mini-tts$0.012Accepts instructions for voice direction.
(gpt-4o-mini-tts is billed by tokens upstream; published per 1k chars equivalent for parity with the rest of the table. Override per-call via Patter(pricing={"openai_tts": {"models": {"tts-1": {"price": ...}}}}).)

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Voices

Built-in voices accepted by all three models: alloy (default), ash, ballad, coral, echo, fable, nova, onyx, sage, shimmer, verse.

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Languages

OpenAI TTS automatically follows the language of the input text — no language parameter exists. The same voice can synthesize across most of OpenAI’s supported languages (English, Spanish, French, German, Italian, Portuguese, Japanese, Chinese, …) — see the OpenAI voice guide for the full coverage matrix.

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Voice direction (gpt-4o-mini-tts only)

Pass instructions= to steer tone, pacing, and accent: 
tts = OpenAITTS(
    api_key="sk-...",
    model="gpt-4o-mini-tts",
    voice="sage",
    instructions="Speak in a warm, empathetic tone, like a customer support specialist.",
)
tts-1 and tts-1-hd reject instructions with a 400 — the SDK silently drops the field for those models so you can swap freely.

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Options

OptionDefaultNotes
api_keyNoneReads from OPENAI_API_KEY when omitted.
model"tts-1""tts-1", "tts-1-hd", "gpt-4o-mini-tts".
voice"alloy"Any of the 11 built-in voices above.
instructionsNoneVoice-direction prompt (ignored for legacy models).
speedNoneFloat in [0.25, 4.0].
target_sample_rate160008000 or 16000 Hz — chooses the resampler chain.

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Low-level usage

from getpatter.providers.openai_tts import OpenAITTS

tts = OpenAITTS(api_key="sk-...", voice="nova", model="tts-1")
async for chunk in tts.synthesize("Hello from the Patter pipeline."):
    ...
await tts.close()