They are provided via the virustotal links on the github release page  https://github.com/KomodoPlatform/Agama/releases

The link urls actually contain the sha256 checksum

For example:

osx: https://www.virustotal.com/#/file/bd38bdd5d3ae1ee23ac28dab8bd819de9ba15a888e3e531514c36b0d7cc9d100/detection

From my own download of 0.2.41d:

$ shasum -a 256 ~/Downloads/Agama_OSX_0.2.41d.tar.gz 
bd38bdd5d3ae1ee23ac28dab8bd819de9ba15a888e3e531514c36b0d7cc9d100