imessage-exporter

This crate provides both a library to interact with iMessage data as well as a binary that can perform some useful read-only operations using that data. The aim of this project is to provide the most comprehensive and accurate representation of iMessage data available.

This free and open-source software can:

Save, export, backup, and archive iMessage data to open, portable formats
Preserve multimedia content (images, videos, audio) from conversations
Facilitate easy migration of message history between devices and platforms
Run diagnostics on the iMessage database
Give you full ownership and control over your communication history
Support compliance with data retention policies or legal requirements
Run on macOS, Linux, and Windows

via https://korben.info/imessage-exporter-recuperer-conversations-apple.html