Imessage
Backup
Instructions from reddit thread
Instructions for installing iMessage-exporter for people who don't code:
1.     First install Rust which contains Cargo:
a.     Open Terminal by going to Finder, Utilities, Terminal
b.     Type this:Â
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
c.     Hit enter
d.     Hit enter again when it prompts you if you want to customize or proceed with standard installation
e.     Close the Terminal window by hitting X (this makes Rust take effect)
2.     Now install the iMesssage-exporter tool
a.     Reopen Terminal by going to Finder, Utilities, Terminal
b.     Type this: This will run for a bit and then throw an error.
cargo install imessage-exporter
c.     You will be asked to install command line developer tools.Â
d.     Tap on “install”.
e.     Tap on “Agree” to the terms and conditions. This install takes a good few minutes so be patient.
f.      Now go back to that Terminal window and rerun the cargo install:
g.     Tap on the Terminal, arrow up to bring back the last command, then hit enter.
3.     You are ready to run iMessage-exporter. Note that this will run for a while, depending on how many text messages you have downloaded in the Messages app. In your Terminal window, type this command (where XXXXXX is your Mac username): /Users/XXXXXX/.cargo/bin/imessage-exporter -f html -c compatibleÂ
/Users/kautilya/.cargo/bin/imessage-exporter -f html -c full
Give access to terminal or iterm for Full Disk access
in macOS -> Settings -> Privacy and Security
4.     To find the exported files, open Finder and navigate to /Users/XXXXXX/imessage_export. They are html files and named after the phone number. Sort them by size to easily locate your top contacts.