List all packages of a given repository

On my Linux Mint 22 Cinnamon Framework 13:

apt list | wc -l

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

81139

apt list --installed | wc -l

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

4712

To investigate Wikipedia: Termux#Package repositories (1246508231).