API Test Type

The API test type provides visibility into the performance of critical web API endpoints within your application ecosystem, as seen from the vantage point of a ThousandEyes Cloud or Enterprise Agent. You can use the Step Builder to configure a single test that makes multiple API calls to different endpoints, and pass results as variables from one call to the next.

You can use proxy settings as described on Collecting Proxy Metrics. Proxy settings for your API test can use either Enterprise Agent proxy settings, or use a test-level proxy setting that overrides the agent setting. The feature works with both static and PAC proxies. Network measurements to the proxy are off by default, but can be enabled.

API Endpoint Types Supported

The API test type supports any HTTP endpoint for sending a request, receiving a response, and capturing the timing. There are some aspects of functionality that are only available with JSON endpoints, particularly the variable processing in the Post-Request Options tab of the Step Builder. See Using the Step Builder for more information.

Who Uses the API Test Type?

Potential users of the API test type include:

  • Network teams, such as IT operations, Network Operations Center (NOC) engineers, Site Reliability Engineers (SREs), and NetOps, who care about application performance

  • Application developers or IT tools teams who monitor back-end functionality for both third-party APIs and APIs that they own Network architects, leaders, and administrators who care about critical 3rd-party API dependencies

These key users can use the API test type to do:

  • Correlate user experience with 3rd party backend application failures.

  • Expose and diagnose functional API performance degradations.

You don’t need to know how to write JavaScript code to use the ThousandEyes API test type; however, for more complex API testing, it’s helpful to be familiar with JSON syntax. You’ll need the API specification.

API Test Type Value-Add

  • No JavaScript scripting expertise required. Instead, an intuitive Step Builder guides you through creation of both simple and complex API tests. You need to know a little bit about JSON syntax and web API specifications such as this example, but that’s about it.

  • API visibility beyond simple ping testing. You can set assertions to validate API responses, and correlate these responses with overall API and network performance.

  • Testing APIs at scale. ThousandEyes Cloud and Enterprise Agents can efficiently run API tests containing multi-step API calls, that pass variables between steps within a single test.

API Tests Use BrowserBot

Although the API test type doesn’t use a browser, it does rely on the BrowserBot component within the ThousandEyes Cloud and Enterprise Agents. Therefore, Enterprise Agent interface selection is not available for the API test type. However, not all device footprints support BrowserBot, so if you want to run API tests from your own Enterprise Agents, those agents need to be installed on devices that have the capacity to run BrowserBot as well as the basic ThousandEyes agent software.

When calculating the number of Enterprise Agents you need to run your testing suite, it’s important to note that API tests run on a separate queue from page load and transaction tests.

For more information, see:

Test Settings for API Test Type

Most of the test settings for the API test type are in the Step Builder, along with the test settings used by other ThousandEyes test types.

The API test type supports both client certificate authentication and disable SSL verification, similar to all other web test types.

  • Adding client certificates for your API test be found under Test Settings, on the TLS section of the Advanced Settings tab. This setting applies to the entire API test and all steps within it.

  • Disabling SSL verification for each API call can be configured in the Authentication tab of the API Step Builder. This setting applies to a single step (API call) of the API test.

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