Need to share pages pages and files on read only and read/write permissions with API REST

[Deleted user]

I need to do the following things with API REST calls:

1. Give an user permission to ONLY READ a space content, with this considerations:
   
   1. The user A (who gave the permissions) is not an admin
   2. The space to share is the personal space of user A
   3. User B (who is invited to see the space) can only read the content a download the files inside the space
   4. User B is not an admin
2. Share subdirs (pages) between user A and user B, with this considerations:
   1. The users (A and B) are not admins
   2. Both users have personal spaces
   3. The content which we want to share are inside both personal spaces
   4. The users would see and download the content of the space

In both cases:

1. The users are valids Confluence Users
2. It may grow to more than two users
3. I need one or more API REST method that allows me to do this.

I have been search in the API REST documentations but had no success finding a method that allows me to do what I listed above.