There are few things more useful than a set of examples when starting to work with a new API. Here are some I’ve started collecting up for my work:

The first of three articles: More. Policy

Get a token. This user has the role ‘admin’ in a project, which means they can execute admin operations.
Save the following in a file named token-request.json

{
    "auth": {
        "identity": {
            "methods": [
                "password"
            ],
            "password": {
                "user": {
                    "domain": {
                        "name": "Default"
                    },
                    "name": "admin",
                    "password": "freeipa4all"
                }
            }
        },
        "scope": {
            "project": {
                "domain": {
                    "name": "Default"
                },
                "name": "demo"
            }
        }
    }
}

And execute it with

export TOKEN=`curl -si -d @token-request.json -H "Content-type: application/json" http://localhost:35357/v3/auth/tokens | awk '/X-Subject-Token/ {print $2}'`

To list domains

curl -si -H"X-Auth-Token:$TOKEN" -H "Content-type: application/json" http://localhost:35357/v3/domains

Create a domain

 curl  -H"X-Auth-Token:$TOKEN" -H "Content-type: application/json" -d '{"domain": {"description": "--optional--", "enabled": true, "name": "dom1"}}'  http://localhost:35357/v3/domains

To list users

curl -si -H"X-Auth-Token:$TOKEN" -H "Content-type: application/json" http://localhost:35357/v3/users

To create a users, create file named create_user.json file like this:

{ 
    "user": { 
           "default_project_id": "d0f445c3379b48f38a2ab0f17314bbf9", 
            "description": "Description", 
            "domain_id": "default",
            "email": "ayoung@redhat.com", 
            "enabled": true, 
            "name": "ayoung", 
            "password": "changeme" } 
}

Execute it like this

curl -si -H"X-Auth-Token:$TOKEN" -H "Content-type: application/json" http://localhost:35357/v3/users -d @create_user.json

The response should look like this, with different auto-generated IDs.

{"user": {"description": "Description", "links": {"self": "http://192.168.0.2:5000/v3/users/8221b007376a40ce8459c05f90077f16"}, "enabled": true, "email": "ayoung@redhat.com", "default_project_id": "d0f445c3379b48f38a2ab0f17314bbf9", "id": "8221b007376a40ce8459c05f90077f16", "domain_id": "default", "name": "ayoung"}}

Note that in the above case the new user_id is 8221b007376a40ce8459c05f90077f16. Use that to get the user directly:

$ curl  -H"X-Auth-Token:$TOKEN" -H "Content-type: application/json"   http://localhost:35357/v3/users/8221b007376a40ce8459c05f90077f16
{"user": {"name": "ayoung", "links": {"self": "http://192.168.0.2:5000/v3/users/8221b007376a40ce8459c05f90077f16"}, "enabled": true, "email": "ayoung@redhat.com...", "default_project_id": "d0f445c3379b48f38a2ab0f17314bbf9", "id": "8221b007376a40ce8459c05f90077f16", "domain_id": "default", "description": "Description"}}

To figure out how to do additional operations, see the V3 Identity API.