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Getting started with the List lookup endpoint

This quick start guide will help you make your first request to the List lookup endpoint using Postman. Please visit our X API v2 sample code GitHub repository if you want to see sample code in different languages. **Note: **For this example, we will make a request to the _List lookup by ID _endpoint, but you can apply the learnings from this quick start to other lookup requests as well.

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Prerequisites

To complete this guide, you will need to have a set of keys and tokens to authenticate your request. You can generate these keys and tokens by following these steps:
  • Sign up for a developer account and receive approval.
  • Create a Project and an associated developer App in the developer portal.
  • Navigate to your App’s “Keys and tokens” page to generate the required credentials. Make sure to save all credentials in a secure location.

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Steps to build a List lookup request

Step one: Start with a tool or library There are several different tools, code examples, and libraries that you can use to make a request to this endpoint, but we will use the Postman tool here to simplify the process. To load the X API v2 Postman collection into your environment, please click on the following button:
Once you have the X API v2 collection loaded in Postman, navigate to the “List” folder, select another folder “List lookup”, and then choose “List by ID”.   Step two: Authenticate your request To properly make a request to the X API, you need to verify that you have permission. To do this with this endpoint, you must authenticate your request with either App only, OAuth 2.0 Authorization Code with PKCE, or OAuth 1.0a User Context authentication methods. For simplicity’s sake, we are going to utilize App only with this request, but if you’d like to request private metrics or Lists, you will need to use one of the other authentication methods.  To utilize App only, you must add your keys and tokens (specifically theApp only Access Token) to Postman by selecting the environment named “X API v2” (in the top-right corner of Postman), and adding your keys and tokens to the “initial value” and “current value” fields (by clicking the eye icon next to the environment dropdown). If you’ve done this correctly, these variables will automatically be pulled into the request’s authorization tab.   Step three: Identify and specify which List you would like to retrieve You must specify a List that you would like to receive within the request. You can find the List ID by navigating to x.com and clicking on a List and then looking in the URL. For example, the following URL’s List ID is 84839422. https://x.com/i/lists/84839422 The target ID can be any valid List ID. In Postman, navigate to the “Params” tab, and enter your ID into the “Value” column of the id path variable. Be sure not to include any spaces before or after any ID.
KeyValue
id84839422 (The List ID)
Step four: Identify and specify which fields you would like to retrieve If you click the “Send” button after step three, you will receive the default List object fields in your response: id, name. If you would like to receive additional fields, you will have to specify those fields in your request with list.fields and/or expansion parameters. For this exercise, we will request three additional sets of fields from different objects:
  • The additional created_at field in the primary Lists object.
  • The full user object using the expansion parameter
  • The additional user.created_at field in the associated user object.
In Postman, navigate to the “Params” tab and add the following key:value pair to the “Query Params” table:
KeyValueReturned fields
list.fieldscreated_atcreated_at
expansionsowner_idincludes.users.id,
includes.users.name,
includes.users.username
user.fieldscreated_atincludes.users.created_at
You should now see a similar URL next to the “Send” button: https://api.x.com/2/lists/84839422?list.fields=owner_id&expansions=owner_id&user.fields=created_at Step five: Make your request and review your response Once you have everything set up, hit the “Send” button, and you will receive a similar response to the following example response: 
{
  "data": {
    "id": "84839422",
    "name": "Official Twitter Accounts",
    "owner_id": "783214"
  },
  "includes": {
    "users": [
      {
        "name": "Twitter",
        "created_at": "2007-02-20T14:35:54.000Z",
        "username": "Twitter",
        "id": "783214"
      }
    ]
  }
}