Spechle.xyz API endpoint to send modifyed JSON back to Speckle.xyz

Hi,

if I make changes to the json with my own software can I send them back to Speckle.xyz ? which is the REST API endpoint ?

How to estimate new hashes for objects (ids) ?

Should be the ids persistent among commits for the same object ?

How to signal my software to receive the latest commit automatically if a collaborator makes a commit ? Is Speckle Manager broadcasting a message in my PC ?

Currently I can only receive the JSON with Speckle.xyz GraphQL and copy curl button.

Thanks
Dimitrios