Incompatibility due to sigv4 dependency

[bueno12223]

While trying to upgrade the package, I found that it’s locked to sigv4: ^5.0.0, which is deprecated and blocks updates to http: ^1.0.0.
This causes incompatibility with most modern Flutter and Firebase packages.

Problem

The sigv4 package is no longer maintained. From its own description:

“This is not actively maintained. If you’re looking for alternatives, check out aws_client.”

Dependency chain:

cloud_text_to_speech 2.3.2
└─ sigv4: ^5.0.0 (ABANDONED)
└─ http: ^0.13.1

This version constraint prevents compatibility with:

The latest Firebase packages

Most up-to-date Flutter SDKs and ecosystem packages

Proposed Solution

Migrate from sigv4 to aws_client, as recommended by the original sigv4 maintainer.

This will require updating the AWS TTS implementation to use aws_client APIs.
It’s a breaking change for AWS users, but necessary to ensure long-term maintenance and compatibility.

Alternative Approaches

If AWS TTS support is rarely used:

Move AWS support to a separate package, or

Make it an optional dependency

This would allow users relying on Google or Microsoft TTS to continue upgrading without being blocked.

Impact

Without this migration:
Users remain stuck on version 1.1.3
Unable to upgrade to newer http or Firebase versions
Potential future breakage as dependencies evolve