> ## Documentation Index
> Fetch the complete documentation index at: https://docs.galxe.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Single Dimensional Config

> Learn how to configure REST Single-Dimensional Credential

## Overview

REST Single-Dimensional Credential allows you to fetch user data via RESTful APIs and validate user eligibility based on a single condition. It is suitable for when task verification is equivalent to answering the question, *Did this particular user perform this task -- yes or no?*

<Tip>If you want to understand the workflow and considerations of REST credentials, please refer to the [introduction](/quest/credential-api/rest-cred/introduction)</Tip>

***

## Config process

### 1. Finding the Config in Task Settings

The option to configure REST credential can be found in step 3, [Task Settings](https://help.galxe.com/en/articles/9728885-create-quest-tasks-settings) of quest creation on the Galxe Dashboard, under the `Import Your Own Data` task type.

### 2. Basic Config

* **ID Type**

`ID Type` provides various identity options, including social accounts, blockchain addresses, and other unique identifiers.

* **Title**

Give your credential a descriptive title relevant to the task at hand.

* **Credential Source**

Choose `REST` type and select `GET` or `POST` based on your API request type.

* **Type**

Choose `Single Dimension`.

### 3. Configure API

* Input Endpoint URL

GET Request Example:

```plaintext theme={null}
https://api.example.com/check-user?wallet=$address
```

POST Request Example:

```plaintext theme={null}
https://api.example.com/check-user
```

* Add Headers (Optional)

```json theme={null}
`Authorization`: `Bearer YOUR_API_KEY`
```

* Input Body (For POST Requests Only):

```json theme={null}
{
  "check_user_address": "$address"
}
```

### 4. Test API Response

* Input a test address, send the request, and confirm whether the response is correct.

* The response must be in JSON format. Example:

```json theme={null}
  {
    "isWhitelisted": true,
    "balance": 1000
  }
```

### 5. Write Expressions

1. **Whitelist Validation**:

```javascript theme={null}
   function(resp) {
       return resp.isWhitelisted ? 1 : 0;
   }
```

1. **Token Balance Validation**:

```javascript theme={null}
   function(resp) {
       return resp.balance >= 1000 ? 1 : 0;
   }
```

1. **Combined Condition Validation**:

```javascript theme={null}
   function(resp) {
       return resp.isWhitelisted && resp.balance >= 500 ? 1 : 0;
   }
```

### 6. Description

Description of the certificate, supports rich text input, maximum 200 characters.

### 7. Call-to-Action Link

Guide users to specific operation pages to complete interactive tasks.

### 8. Participation End Time & Update Frequency (Optional)

* **Participation End Time**:

Control the time range of the credential, prohibiting new validations after the deadline.

* **Update Frequency**:

Remind users of the frequency of API data source updates, such as once a day or once every two days.

***

## Example

### Polygon OAT Holder

* **Endpoint**

```plaintext theme={null}
https://api.covalenthq.com/v1/matic-mainnet/address/$address/collection/0x5D666F215a85B87Cb042D59662A7ecd2C8Cc44e6/
```

* **Request Type**

`GET`

* **Headers**

```json theme={null}
Authorization: Bearer YOU_API_KEY
```

* **Response**

```plaintext theme={null}
{
  "data": {
      "updated_at": "2023-06-26T05:12:35.553904397Z",
      "address": "0x123",
      "collection": "0x5d666f215a85b87cb042d59662a7ecd2c8cc44e6",
      "is_spam": false,
      "items": []
  },
  "error": false,
  "error_message": null,
  "error_code": null
}
```

* **Expression**

```javascript theme={null}
function(resp) {
  if (resp.data.items != null && resp.data.items.length > 0) {
    return 1
  }
  return 0
}
```

### ETH Balance Holder

* **Endpoint**

```plaintext theme={null}
https://mainnet.infura.io/v3/YOUR-API-KEY
```

* **Request Type**

`POST`

* **Headers**

`No header`

* **Body**

```json theme={null}
{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": [
        "$address",
        "latest"
    ],
    "id": 1
}
```

* **Response**

```json theme={null}
{
    "jsonrpc": "2.0",
    "id": 1,
    "result": "0x7c2562030800"
}

```

* **Expression**

```javascript theme={null}
function(resp) {
  if (BigInt(resp.result) > 0) {
    return 1
  }
  return 0
}
```

### General NFT Holder

* **Endpoint**

```plaintext theme={null}
https://mainnet.infura.io/v3/YOUR-API-KEY
```

* **Request Type**

`POST`

* **Headers**

`No header`

* **Body**

```json theme={null}
{
  "jsonrpc":"2.0",
  "id":1,
  "method":"eth_call",
  "params":[
      {
        "data":"0x70a08231000000000000000000000000$addressWithout0x",
        "to":"0xb47e3cd837dDF8e4c57F05d70Ab865de6e193BBB"
      },
      "latest"
  ]
}
```

* **Response**

```json theme={null}
{
    "jsonrpc": "2.0",
    "id": 1,
    "result": "0x00000000000000000000000000000001"
}
```

* **Expression**

```javascript theme={null}
function(resp) {
  if (BigInt(resp.result) > 0) {
    return 1
  }
  return 0
}
```