Solid Web Monetization Provider - Practical

Purpose

The purpose of this component is to provide a minimal implementation of the proposed Solid Web Monetization provider.

Usage

Docker

The WMP server can be started via Docker Compose:

1. Clone the repository: git clone https://github.com/KNowledgeOnWebScale/solid-web-monetization
2. Open the root repository folder, where the docker-compose.yml file is located: cd solid-web-monetization
3. Execute docker-compose up -d
4. Browse to http://wmp.localhost

Environment variables

Under the wmp.environment section in the docker-compose.yml file, you can set the following environment variables.

name	default	description
HTTP_PORT	HTTP port server is hosted on	8080,
BASE_URI	URI as written in WebID Solid profile document	"http://localhost:$httpPort"
MONGO_CONNECTION_STRING	Connection string to mongodb instance	"mongodb://localhost:27017"
MONGO_DATABASE_NAME	Database name of mongodb database	"demo-wmp"
SUBSCRIPTION_AMOUNT	Subscription amount deducted	5 (long)
SUBSCRIPTION_ASSET_CODE	Subscription assetCode	"USD"
SUBSCRIPTION_ASSET_SCALE	Subscription assetScale	2 (int)
SUBSCRIPTION_INTERVAL	Subscription deduction interval	"P1M",
IDP_URI_SOLID_COMMUNITY	solidcommunity.net IDP configuration URI	"https://solidcommunity.net/.well-known/openid-configuration"
CLIENT_ID (*)	solidcommunity.net clientId of WMP	"b8c75d654bfe324ccae44f1638d5310c"
CLIENT_SECRET (*)	solidcommunity.net clientSecret of WMP	"899fb60c7f7c1b3e67abbaebcaf06904"
API_PATH	Path under which API is hosted	"/api"
AUTH_PATH	Path under which auth is hosted	"/auth"

(*) The WMP must be registered to the IDP solidcommunity.net through dynamic registration. The resulting JSON contains the required CLIENT_ID and CLIENT_SECRET.

Client registration

To register the WMP as client with solidcommunity.net execute the following statement, using the values as you set them for the environment variables.

# HTTP POST to https://solidcommunity.net/register
curl --location --request POST 'https://solidcommunity.net/register' \
--header 'Content-Type: application/json' \
--data-binary @- << EOF
{
    "client_name": "WMP",
    "application_type": "native", 
    "subject_type": "public",
    "redirect_uris": [
         "http://localhost:8080/auth/cb", 
         "http://wmp.localhost/auth/cb"
    ], 
    "post_logout_redirect_uris": [
        "http://localhost:8080/auth/logout/cb",
        "http://wmp.localhost/auth/logout/cb"
    ]
}
EOF

You should receive something like this:

{
    "redirect_uris": [
        "http://localhost:8080/auth/cb",
        "http://wmp.localhost/auth/cb"
    ],
    "client_id": "******",
    "client_secret": "******",
    "response_types": [
        "code"
    ],
    "grant_types": [
        "authorization_code"
    ],
    "application_type": "native",
    "client_name": "WMP",
    "subject_type": "public",
    "id_token_signed_response_alg": "RS256",
    "token_endpoint_auth_method": "client_secret_basic",
    "post_logout_redirect_uris": [
        "http://localhost:8080/auth/logout/cb",
        "http://wmp.localhost/auth/logout/cb"
    ],
    "registration_access_token": "eyJhbGciOiJSUzI1NiJ9.eyJpc3M...IyYmEifQ.ifK5xi45...gsUJex_GfXJg",
    "registration_client_uri": "https://solidcommunity.net/register/38f951e27363209239712c5a5e6122ba",
    "client_id_issued_at": 1643387461,
    "client_secret_expires_at": 0
}

You can now use those client_id and client_secret values to pass as environment variables to the server. They can be edited in the docker-compose.yml.

Login

Although in theory it should not matter which Solid pod and thus Solid WebID you use, this demonstrator has been hardwired to authenticate with solidcommunity.net. So you will need an account and pod there.

That is why you should create a solid pod over at solidcommunity.net, if you did not so already.

About page

There is nothing noteworthy about this page. Once logged in, it outputs your Solid WebID Profile URI.

Manage page

If you do not have a subscription to this WMP yet, this page shows a form with all payment pointers found inside you WebID Profile document. If there aren't any listed, you have to use the Accountant application first.

After selecting your preferred payment pointer and clicking Subscribe with WebID, your subscription is stored.

Now that you have a subscripton all details should be shown. Along with your subscription a Mandate is now created at your payment pointers wallet following the Open Payments draft specification.

Now your wallet is charged according to the environment variables set for the WMP server. This effectively funds the WMP to do payments on its user's behalf.

Solid application

Following the Solid ideology, the payment pointers are queried from the user's Solid pod and the user's WMP is stored in the user's Solid pod.