Jenkins MCP Server v2.9.9

Released 2026-08-13.

Highlights

• Job discovery, job details, and build details now expose only their documented
  response contracts instead of forwarding arbitrary Jenkins/plugin objects.
• Build parameter values identified as passwords, tokens, secrets, or
  credentials are redacted before they cross the MCP boundary.

New Features

• None.

Improvements

• get_job and get_build_info now use narrow Jenkins tree queries, reducing
  controller serialization work and MCP response size.
• Shared projection helpers keep scalar fields, nested build references, health
  reports, and parameter handling consistent across the structured read tools.
• Tool descriptions, the compatibility contract, security guidance,
  troubleshooting, and the Jenkins-through-Minibridge smoke now describe and
  verify the projected response boundary.

Bug Fixes

• list_jobs preserved unexpected top-level response fields even though its
  public contract contains only the filtered jobs collection.
• Individual list_jobs entries were returned verbatim, allowing action/plugin
  objects not requested by the documented contract to cross the boundary.
• Folder listings that had only a child name were policy-checked against a
  reconstructed path but returned no fullName; the response now includes the
  same canonical path that was authorized.
• get_job returned depth-two action/property objects and upstream/downstream
  job references, which could disclose metadata outside the allowed job's
  documented state and build-reference contract.
• get_build_info returned unrelated action, cause, artifact, change-set, and
  plugin payloads rather than its documented result/timing/parameter contract.
• Password/token/credential parameter classes and secret-like parameter names
  could return their values; those values are now replaced with [redacted],
  while non-scalar plugin values receive an explicit unsupported marker.
• Malformed nested job/build response structures could produce raw iteration or
  attribute errors instead of stable JenkinsError diagnostics.
• Boolean, float, or string console offsets could reach Jenkins despite the
  public non-negative integer contract.
• Invalid X-More-Data, a missing cursor while more data remained, or a
  regressive cursor on a completed page could silently stop or corrupt console
  pagination.

Breaking Changes

• None. Documented identity/state/health/build/timing fields and the existing
  Jenkins actions[].parameters[] shape remain available. Undocumented raw
  plugin, relation, cause, artifact, and change-set passthrough is intentionally
  removed.

Known Issues

• Jenkins string parameters can contain sensitive data under an innocuous name.
  Use Jenkins password/credential parameter types and secret-like names so the
  server can identify them; do not place secrets in ordinary string parameters.

Security

• Structured job and build reads now fail closed on malformed nested objects and
  project only explicitly documented fields.
• Allowed-job detail responses no longer carry upstream/downstream job objects,
  closing an indirect metadata path around MCP_ALLOWED_JOBS.
• Sensitive build parameters are redacted by parameter name and Jenkins class;
  arbitrary nested parameter values are never forwarded.

Upgrade Notes

• No configuration changes are required. Reconnect MCP sessions after rollout
  so clients refresh the strengthened tool descriptions and response contract.