Last modified on February 19, 2018

An API endpoint monitor sends an HTTP request to the specified URL and checks the response time and status. You can specify the request headers and payload, such as JSON or XML data.

API endpoint monitors can be used both for REST and SOAP APIs.

Basic knowledge of HTTP request and response contents is recommended to use API endpoint monitors.

Step 1: Configure Request URL, Headers, and Body

Start on the AlertSite UXM Dashboard, hover over + Add New, then select Monitor from the dropdown. Select API on the left, then click Single API Endpoint Monitor.

Creating an API endpoint monitor in AlertSite

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On the next screen, you can configure the request – specify the URL (including http:// or https://), request method (GET, POST or other), headers and body. The body is used only for POST, PUT and PATCH requests.

Alternatively, you can click Swagger and import an OpenAPI (Swagger) definition that describes your API endpoints and parameters.

Configuring an API request in AlertSite

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If you are sending a request body, such as JSON or XML, select the appropriate content type from the list. To use a different content type, select Custom and add the corresponding Content-Type header manually.


  • Query string parameters should have unique names. Multiple parameters with the same name (such as ?tag=cats&tag=dog) are not supported.

  • When sending a body, make sure the body syntax is correct. AlertSite’s request editor validates the JSON syntax. If you are posting XML, use to check your XML syntax.

Request Examples

POST JSON data and receive a JSON response

POST form data

SOAP 1.2 request

SOAP 1.1 request


API endpoint monitors support Basic authentication. It is a widely used method for simple username/password authentication and involves sending the encoded credentials in the Authorization header in requests.

To authenticate the request, switch to the Authentication tab, select the check box and enter the username and password.

Username and password for Basic 

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Authenticating preemptively

Other authentication types


If the target URL uses query parameters, such as, you can append them directly to the URL, or specify them in the Parameters table. The request URL and the Parameters table are synchronized and automatically updated as you change either of them.

The parameter editor is handy if some parameter values contain reserved characters such as % ! & or others – you can enter the values as they are, and AlertSite will automatically encode these values in the request URL.

Click to add a new parameter, or to delete a specific parameter.

Query parameter editor

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Note: Query parameters must have unique names. AlertSite API monitors do not support multiple query parameters with the same name.

Test the Request

After you have entered the request data, click Validate to send a sample request and see the response. If there is an error, go back and double-check the request configuration (URL, headers and body).

Add Assertions (Recommended)

Assertions are used to verify the data returned in the response body. For example, you can check the value of a specific JSON field, or search for a specific word in the response text. When a monitor runs the test, it is considered successful only if all of the assertions pass.

To add an assertion, click a line in JSON or select text in a text response, and click Add Assertion. You can also add assertions manually to the table. To learn more, see API Assertions.

API assertions

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Step 2: Configure Monitoring Settings

After you configure the request and add assertions, click Next to proceed.

On the next screen, you can give your monitor a name, select a run interval, timeout and the locations where the monitor will run. More settings are displayed if you click Edit Configurations in the top right corner. One useful setting that you can access via Edit Configurations is Capture Level. It lets you store request and response contents obtained during the test runs. For a description of all the settings, see API Endpoint Monitor Settings. You will be able to change all the settings later, if needed.

Note: VM Node and InSite plans and locations are currently not supported for API endpoint monitors.
Selecting locations for an API endpoint monitor

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Once done, click Start Monitoring Now in the top right corner to create the monitor.

AlertSite will now monitor your API endpoint and alert you on errors. The first results will appear on the AlertSite Dashboard in a few minutes.

What’s Next

See Also

API Endpoint Monitor Settings
Converting API Endpoint Monitors to SoapUI
Creating API Monitors From OpenAPI (Swagger) Definitions