Using the APIs Explorer

This guide describes how to use the APIs Explorer to try out Cloud Monitoring API methods. APIs Explorer is a widget attached to the REST API reference page for a method. It appears as a panel with the title Try this API. The following screenshot shows the panel as it appears for a method with only one parameter, name:

The APIs Explorer widget.

The APIs Explorer is an excellent way to try out methods in the Cloud Monitoring API without having to write any code. The widget presents a form showing the parameters for each method. Fill in the form, click the Execute button, and see the results.

You can also hide the widget by clicking the button, or expand the widget to full screen by clicking the button.

Try It! buttons

In the documentation, you might see Try It! buttons like the following:

Try It!

When you click the button, the APIs Explorer on the method's reference page opens. Typically, some parameters appropriate to the example are populated; however, you might have to edit some of the parameters to match your own project, such as the value for [PROJECT_ID].

For information about avoiding and fixing errors, see Troubleshoot.

Access the APIs Explorer

The APIs Explorer is attached to the reference page for each REST API method. To find the widget, see the reference page for a method, for example, see metricDescriptors.list.

Execute a request

Most methods have some required parameters and some optional ones. The required ones are marked with a red bar until they are filled. You can execute a request after supplying values for all required arguments.

The metricDescriptors.list method returns descriptors for all available metric types in a project. The only required parameter is the name parameter.

To execute the metricDescriptors.list method, do the following:

  1. Click Try It!
  2. In the name parameter, enter your project's ID using the format projects/[PROJECT_ID]. Be sure to replace [PROJECT_ID] with your project's ID.
  3. Click Execute. To execute the command, APIs Explorer requires access to your account. When prompted, select an account and click Allow. Access is for a limited time period and restricted to the API method you are executing.

The results of the method invocation appear in a box which has a green or red header. When the request succeeds, the box has a green header with the HTTP status code 200 in it. The results of the invocation are in the box:

The result of a successful method invocation.

When the header is red, it contains an HTTP failure code, and the box contains the error message. For information about resolving errors, see Troubleshoot.

Supply additional parameters

The list of parameters you see depends on the method to which the APIs Explorer widget is attached. For example, the metricDescriptors.list method has more than the name parameter, but name is the only required parameter.

When you provide only the project name, you get all the metric descriptors available in your project, and there are many of them. To restrict the retrieval to a smaller set, use the filter parameter.

For example, to list only those metrics types whose name ends with utilization, do the following:

  1. Click Try It!

  2. In the name parameter, enter your project's ID using the format projects/[PROJECT_ID]. Be sure to replace [PROJECT_ID] with your project's ID.

  3. Ensure the filter parameter has the value metric.type=ends_with("utilization")

  4. Click Execute and complete the authorization dialogs.

Standard parameters

By default, the set of parameters that APIs Explorer shows corresponds to the parameters of the associated method. However, the APIs Explorer widget also has a set of extra parameters that aren't part of the method itself. To display the extra parameters, click Show standard parameters:

Show standard parameters toggle.

To hide the extra parameters from the display, click Hide standard parameters.

The most useful standard parameter is the fields parameter. This parameter lets you select the fields in the returned output that you want to see.

For example, listing the descriptors for metrics ending with utilization still returns many results. If you only want to know the name of the metric type and its description, then you can specify this restriction by using the fields parameter.

To see the result of setting the fields parameter, do the following:

  1. Click Try It!

  2. In the name parameter, enter your project's ID using the format projects/[PROJECT_ID]. Be sure to replace [PROJECT_ID] with your project's ID.

  3. Ensure the filter parameter has the value metric.type=ends_with("utilization")

  4. Click Show standard parameters, and verify the fields parameter has the value metricDescriptors.type,metricDescriptors.description

  5. Click Execute and complete the authorization dialogs.

Executing this request returns only the type (short name) of each metric and its description.


This section describes common issues when using APIs Explorer.

For more information about using the Cloud Monitoring API, see Troubleshooting the Cloud Monitoring API.

Invalid filter syntax

You copy a multi-line expression and paste it into a field shown in APIs Explorer, but APIs Explorer displays an error message.

Do: Ensure that strings are on a single line.

"query": "fetch | within 5m"

Don't: Copy and paste line-continuation or new-line characters.

For example, if you add the following to the timeSeries.query method, then APIs Explorer displays the error message Select an underlined section to see more details:

"query": "fetch
          | within 5m"

Invalid project identifier

If the project identifier is invalid, then the API request fails with an HTTP error of 400.

To resolve this condition, verify that the text [PROJECT_ID] was replaced with your project's ID.

Invalid form values

If your API request fails or returns unexpected values, then check all form parameters.

The APIs Explorer parameters require specific formatting. Formatting mistakes might cause errors or they might be accepted but be treated like spelling errors in the API method:

  • Don't use quotation marks around parameter values of any type.
  • Don't use backslashes except when you need to protect a substring.

    For example, the following sample is for an API method where you enter the content as JSON, instead of completing individual form parameters. Because the value for filter is a string, the substring, k8s_cluster, is protected by backslashes:

      "resourceNames": [...],
      "filter": "resource.type = \"k8s_cluster\""
  • Quote strings appearing inside filters. Use double quotation marks (") and not apostrophes ('). For an example, see Supply additional parameters.
  • Don't use URL-encoding in the form. If an API method requires URL-encoding, then the widget performs the conversion when you execute the method.

Too much data is returned

To limit the number of results returned, in the pageSize parameter, enter a value, such as 2. The pageSize parameter defines the maximum number of results that are returned, and is available for most API methods.

To select specific fields to return, use the fields parameter. For more information, see Standard parameters.


There is a Credentials section on the APIs Explorer page. We recommend that you leave these fields at default values. The default authentication mechanism is Google OAuth 2.0.

To find out which API scopes that are required for the method, click Show scopes. By default, all necessary scopes are granted.

For more information about these concepts, see Control access with Identity and Access Management.