AWS Polly

Text-to-speech service using Amazon Polly

Overview

AWSPollyTTSService provides high-quality text-to-speech synthesis through Amazon Polly with support for standard, neural, and generative engines. The service offers extensive language support, SSML features, and voice customization options including prosody controls for pitch, rate, and volume.

AWS Polly API Reference

Pipecat’s API methods for AWS Polly integration

Example Implementation

Complete example with generative engine

AWS Polly Documentation

Official AWS Polly documentation and features

Voice Samples

Browse available voices and languages

Installation

To use AWS Polly services, install the required dependencies:

pip install "pipecat-ai[aws]"

Prerequisites

AWS Account Setup

Before using AWS Polly TTS services, you need:

1. AWS Account: Sign up at AWS Console
2. IAM User: Create an IAM user with Polly permissions
3. Access Keys: Generate access key ID and secret access key
4. Voice Selection: Choose from available voices in the voice list

Required Environment Variables

• AWS_ACCESS_KEY_ID: Your AWS access key ID
• AWS_SECRET_ACCESS_KEY: Your AWS secret access key
• AWS_SESSION_TOKEN: Session token (if using temporary credentials)
• AWS_REGION: AWS region (defaults to “us-east-1”)

Configuration

AWSPollyTTSService

api_key · str · default: "None"

AWS secret access key. If None, uses the AWS_SECRET_ACCESS_KEY environment variable.

aws_access_key_id · str · default: "None"

AWS access key ID. If None, uses the AWS_ACCESS_KEY_ID environment variable.

aws_session_token · str · default: "None"

AWS session token for temporary credentials.

region · str · default: "None"

AWS region for Polly service. Defaults to us-east-1 if not set via environment variable.

voice_id · str · default: "Joanna" · deprecated

Voice ID to use for synthesis. Deprecated in v0.0.105. Use settings=AWSPollyTTSService.Settings(voice=...) instead.

sample_rate · int · default: "None"

Output audio sample rate in Hz. When None, uses the pipeline’s configured sample rate. AWS Polly internally synthesizes at 16kHz and resamples to the target rate.

params · InputParams · default: "None" · deprecated

Deprecated in v0.0.105. Use settings=AWSPollyTTSService.Settings(...) instead.

settings · AWSPollyTTSService.Settings · default: "None"

Runtime-configurable settings. See Settings below.

Settings

Runtime-configurable settings passed via the settings constructor argument using AWSPollyTTSService.Settings(...). These can be updated mid-conversation with TTSUpdateSettingsFrame. See Service Settings for details.

Parameter	Type	Default	Description
model	str	None	Model identifier. (Inherited.)
voice	str	None	Voice identifier. (Inherited.)
language	Language | str	None	Language for synthesis. (Inherited.)
engine	str	NOT_GIVEN	Engine type (e.g., “neural”, “standard”).
pitch	str	NOT_GIVEN	Pitch adjustment for SSML.
rate	str	NOT_GIVEN	Speaking rate for SSML.
volume	str	NOT_GIVEN	Volume for SSML.
lexicon_names	List[str]	NOT_GIVEN	List of lexicon names for pronunciation.

Usage

Basic Setup

from pipecat.services.aws import AWSPollyTTSService

tts = AWSPollyTTSService(
    settings=AWSPollyTTSService.Settings(
        voice="Joanna",
    ),
)

With Voice Customization

from pipecat.transcriptions.language import Language

tts = AWSPollyTTSService(
    api_key=os.getenv("AWS_SECRET_ACCESS_KEY"),
    aws_access_key_id=os.getenv("AWS_ACCESS_KEY_ID"),
    region="us-east-1",
    settings=AWSPollyTTSService.Settings(
        voice="Matthew",
        engine="neural",
        language=Language.EN_US,
        rate="110%",
        volume="loud",
    ),
)

The InputParams / params= pattern is deprecated as of v0.0.105. Use Settings / settings= instead. See the Service Settings guide for migration details.

Notes

• Engine selection: AWS Polly supports "standard", "neural", and "generative" engines. Not all voices support all engines. Check the AWS voice list for compatibility.
• Pitch control: The pitch parameter only works with the "standard" engine. Neural and generative engines ignore it.
• Audio resampling: Polly synthesizes PCM at 16kHz internally. The service automatically resamples to match your pipeline’s sample rate.