Configure a custom authentication algorithm

  • Release version: Zurich
  • Updated July 31, 2025
  • 1 minute to read

    • Generate the custom data needed to authenticate to a web service by running script.

    Before you begin

    • JavaScript knowledge
    • REST knowledge
    • Target web service API knowledge
    • Connection, credential, and alias knowledge
    • Role required: Developer

    About this task

    Use a connection and credential alias and custom authentication based algorithm for authentication.

    Procedure

    1. Navigate to All > Credentials & Connections > Authentication Algorithms, and click New.
    2. On the form, fill in the fields.
      The database selection in the Format field determines which fields are available.
      Table 1. Authentication form
      Field Description
      Name Unique name of this algorithm.
      Algorithm Outbound request type. Select Custom Authentication.
      Description Description of what your algorithm does.
      Application Scope that your application runs in.
      Instance Authentication Script Script that you select from the Script Includes table. The scripts available are as follows:
      • RequestAuthAWSV4Signer
      • RequestAuthInternal
      • RequestAuthSampleCustomSigner
      • RequestAuthTwitterSigner
      Note:
      • To know more about the script click the information icon next to the field. The details of the script such as Name, API Name, Application, Accessible from, Script, and so on is displayed.
      • In case of custom authentication with Twitter, you can choose RequestAuthTwitterSigner, since it uses an OAuth 1.0a method of authentication. This requires informations such as API key and secret and Access token and secret that can be used to create signatures to pass in an authorization header. For more information, see Authentication in Twitter.
      MID Authentication Script Script that you select from the MID Server Script Includes [Discovery view] table. The scripts available are as follows:
      • RequestAuthAWSV4Signer
      • RequestAuthInternal
      • RequestAuthSampleCustomSigner
      • RequestAuthTwitterSigner
      Twitter authentication algorithm

      Based on the selected scripts and authentication algorithm, the configured credentials is sent as outbound request from ServiceNow to the provider.

    3. Click Update.
    4. Navigate to All > Connections & Credentials > Credentials.
    5. Click New.
    6. Create Twitter Credentials with Authentication Algorithm.
      In this case TwitterAuthAlgo.
    7. Specify the fields:
      • Name
      • Active
      • Access token
      • Access token secret
      • Consumer key
      • Consumer secret
      • Credential alias
      • Authentication Algorithm
      Twitter Credentials
    8. Click Update.

    REST step with Twitter

    In case of Twitter, you must ensure the following spokes or credentials are available:

    • Access token
    • Access token secret
    • Consumer key
    • Consumer secret
    • Authentication Algorithm

    Action: TwitterAuthAlgo.

    Input REST step with Twitter as follows:
    • Credentials Alias: The alias that is created for Twitter.
    • Base URL: Base URL details from Twitter.
    • HTTPS Method: In this case it is POST method. Posting a tweet.
    • Query Parameters: Action as tweet.
    Post Tweet

    You can test the action. The tweet is posted on the Twitter page.