== AWS Polly Sink Kamelet Description

=== Authentication methods

In this Kamelet you can avoid using explicit static credentials by specifying the `useDefaultCredentialsProvider` option and set it to `true`.

The order of evaluation for Default Credentials Provider is the following:

 - Java system properties - `aws.accessKeyId` and `aws.secretKey`.
 - Environment variables - `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`.
 - Web Identity Token from AWS STS.
 - The shared credentials and config files.
 - Amazon ECS container credentials - loaded from the Amazon ECS if the environment variable `AWS_CONTAINER_CREDENTIALS_RELATIVE_URI` is set.
 - Amazon EC2 Instance profile credentials.

You can also use the Profile Credentials Provider, by setting the `useProfileCredentialsProvider` option to `true` and `profileCredentialsName` to the profile name.

Only one of access key/secret key or default credentials provider could be used

For more information, see the https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/credentials.html[AWS credentials documentation]

=== Speech Synthesis

The kamelet sends text to AWS Polly for speech synthesis and returns the audio stream in the configured output format. The message body should contain the text to synthesize.

=== Voice Selection

Use the `voiceId` parameter to select a specific voice (e.g., `Joanna`, `Matthew`, `Amy`, `Brian`). If not set, the voice ID can be provided via the `CamelAwsPollyVoiceId` message header.

=== Engine Selection

Amazon Polly supports multiple engines:

 - *standard* - Standard synthesis engine.
 - *neural* - Neural synthesis engine for more natural sounding speech.
 - *long-form* - Optimized for long-form content like articles and books.
 - *generative* - Generative synthesis engine for the most expressive and natural speech.

=== Output Formats

The following output formats are supported:

 - *MP3* (default) - MP3 audio format.
 - *OggVorbis* - Ogg Vorbis audio format.
 - *Pcm* - Raw PCM audio format.
 - *Json* - Speech marks in JSON format.

=== SSML Support

Set the `textType` parameter to `SSML` to use Speech Synthesis Markup Language for fine-grained control over pronunciation, volume, pitch, and speech rate.
