Inspect a build's tests with the Test Engine API and MCP Server

The new Test Engine Build tests API returns the tests that ran in a specific Buildkite Pipelines build.

Each test includes its reliability, average, total, minimum, and maximum duration, execution count, and counts by result for the build. You can filter by branch, labels, owners, state, or execution tags, sort by reliability or duration, and paginate through the results.

The Buildkite MCP Server also includes list_tests_for_build, a read-only tool that gives AI agents access to the same build-specific test details and metrics. This helps agents identify the slowest or least reliable tests in a build.

Both the API endpoint and MCP tool require the build UUID and the read_suites scope. The tool is part of the Test Engine toolset and is available in the open-source MCP server and the Remote MCP server.