buildkite-mcp-serverBLOCK

[](https://buildkite.com/buildkite/buildkite-mcp-server)

[Model Context Protocol (MCP)](https://modelcontextprotocol.io/introduction) server exposing Buildkite data (pipelines, builds, jobs, tests) to AI tooling and editors.

Full documentation is available at buildkite.com/docs/apis/mcp-server.

Comparing builds

The read-only compare_builds tool in the investigations toolset answers questions such as “What changed since this build last worked on main?” Supply org_slug, pipeline_slug, and the target build_number. It selects the most recently created earlier build that is currently passed on the same pipeline and exact branch. It does not require that the baseline had already passed when the target started. Supply baseline_build_number to compare against a specific build in that pipeline instead, including a failed build or one on another branch.

The response identifies the baseline and selection rule, counts outcomes across all jobs, and returns up to 100 job comparisons, prioritizing newly failing, recovered, and still-failing steps. Matching uses step keys, job type, matrix values, and parallel index/total. When both jobs lack keys, it falls back to the exact nonblank name plus type, group key, matrix values, and parallel index/total, only when that combination is unique in each build. Matched pairs expose match_method: "step_key" or "name_fallback"; fallback matches carry a warning that they are heuristic. Unnamed unkeyed jobs and duplicate identities remain unmatched. Explicit keys never fall back to names, even when a key was added, removed, or changed between builds. Added/removed means a job identity is present in only one build, so renaming unkeyed jobs or changing matrix values or parallelism can also produce added/removed entries. Retried attempt