---
title: 3. Create a Basic Client
slug: guides/3-create-a-basic-client
docTags: 
createdAt: 2024-04-16T19:24:13.354Z
---

:::hint{type="info"}
🌟 **Key Concept: **A [Client](docId\:xLmVFa6LwTzcXpO-XuDq9) is an application that can request Resources from the Resource Server. Client requests can be made either on behalf of an end user or directly from the Client itself.
:::

**This example setup demonstrates how to create a basic Client using the IDENTOS Authorization Server.**

`TODO: Add overview diagram with step emphasized.`

This setup will... *TODO: Introduce example.*

## Prerequisites

- This setup has no prerequisites.

## Step-by-Step Setup

**To create a Client in the Authorization Server, we'll need to:**

1. **Define the Client** **as an OAuth 2.0 client** in the Authorization Server.

For our example, we'll assume that the hospital's Blood Glucose App already exists at a known URI. In an actual authorization flow, this Client would already hold the authorization keys necessary for accessing the Resource Server.

:::hint{type="info"}
For a full explanation of each operation and its parameters, see [Create a Client](docId\:deLhi_bgRp2e4oWFpqc3t).
:::

::::WorkflowBlock
:::WorkflowBlockItem
### Define the Client as an OAuth 2.0 Client

Run the Admin API call below to define the `blood-glucose-app` Client located at `https://bg-app.fakehospital.com/` as an OAuth 2.0 client in the Authorization Server's `oauth-client-metadata` and `oauth-client` databases.

Since this will be the second OAuth client in our Authorization Server, the `blood-glucose-app` will be `id = 2` in both databases.

```curl
curl --location -g --request PATCH '{{AS_ADMIN_URI}}' \
--header 'Content-Type: application/vnd.api+json; ext=jsonpatch' \
--header 'Authorization: {{AS_ADMIN_STATIC_TOKEN}}' \
--header 'ApiVersion: v1.0' \
--header 'Accept-Language: en' \
--data-raw '[
   
    {
        "op": "add",
        "path": "/oauth-client-metadata",
        "value": {
            "id": 2,
            "type": "oauth-client-metadata",
            "attributes": {
                "issuerUri": "https://bg-app.fakehospital.com/",
                "clientAuthenticationType": "private_key_jwt",
                "clientType": "CONFIDENTIAL",
                "grantTypes": "client_credentials",
                "jwksRaw": null,
                "jwksUri": "https://bg-app.fakehospital.com/jwks",
                "scopes": "uma_protection",
                "clientSecret": null
            }
        }
    },
    {
        "op": "add",
        "path": "/oauth-client",
        "value": {
            "type": "oauth-client",
            "id": 2,
            "attributes": {
                "clientId": "blood-glucose-app",
                "clientName": "Blood Glucose App",
                "redirectUris": [
                    "https://blg-app.fakehospital.com/",
                    "{{AS_URI}}"
                ]
            },
            "relationships": {
                "oAuthClientMetaData": {
                    "data": {
                        "type": "oauth-client-metadata",
                        "id": 2
                    }
                }
            }
        }
    },
]'
```
:::

:::WorkflowBlockItem
### View the Client (Optional)

Now check to see if the Client exists.

```curl
curl --location -g --request GET '{{AS_ADMIN_URI}}/oauth-client/4' \
--header 'Content-Type: application/vnd.api+json' \
--header 'ApiVersion: v1.0' \
--header 'Authorization: {{AS_ADMIN_STATIC_TOKEN}}' \
--header 'Accept-Language: en'
```
:::
::::

:::hint{type="success"}
## Next Steps

**✅ You just created a basic Client in the Authorization Server! **

- **Next step: **Proceed to [4. Get an Access Token](docId\:sCyrDYqEMPrTIg6Vbsdxr) to learn how to create and grant an Access Token to the Client you created.
- **Learn more: **Read the [Create a Client](docId\:deLhi_bgRp2e4oWFpqc3t) guide to learn more about creating and managing Clients in the Authorization Server.
:::