Jenkins MCP Server

External Python MCP server for Jenkins 2.563. It connects through normal Jenkins HTTP APIs using the permissions available to JENKINS_USER and JENKINS_API_TOKEN.

It does not require Jenkins administrator access, does not install Jenkins plugins, and does not depend on the official Jenkins MCP Server Plugin.

Python Setup

This project was initialized with pyenv using the latest stable Python 3.14.x available locally:

• Python: 3.14.4
• pyenv virtualenv: venv3144

To reproduce:

pyenv local venv3144
python --version
which python
pyenv version

Install

python -m pip install -e '.[dev]'

Environment

Required:

export JENKINS_URL="https://jenkins.example.com/"
export JENKINS_USER="your-user"
export JENKINS_API_TOKEN="your-api-token"

Optional:

export JENKINS_VERIFY_SSL=1
export JENKINS_TIMEOUT_SECONDS=30
export JENKINS_MCP_MAX_RESPONSE_BYTES=2000000
export JENKINS_MCP_MAX_LOG_BYTES=200000

Workspace bundle downloads are gated separately because they can be very large and may contain secrets or other untrusted files:

export JENKINS_MCP_ENABLE_WORKSPACE_DOWNLOAD=1
export JENKINS_MCP_WORKSPACE_DOWNLOAD_DIR="/absolute/path/with/enough/disk"
export JENKINS_MCP_MAX_WORKSPACE_ARCHIVE_BYTES=6000000000
export JENKINS_MCP_MAX_WORKSPACE_EXTRACT_BYTES=20000000000
export JENKINS_MCP_MAX_WORKSPACE_FILES=200000
export JENKINS_MCP_MAX_BUNDLE_LOG_BYTES=1200000000
export JENKINS_MCP_WORKSPACE_PROGRESS_INTERVAL_SECONDS=2

Write gates:

export JENKINS_MCP_ENABLE_WRITES=1
export JENKINS_MCP_ENABLE_JOB_CONFIG_WRITE=1
export JENKINS_MCP_ENABLE_DELETE=1

Do not store real Jenkins secrets in MCP client config files.

Run STDIO Server

python -m jenkins_mcp_server

Console script:

jenkins-mcp-server

Client Setup

• Codex CLI: docs/codex-setup.md
• Gemini CLI: docs/gemini-setup.md

Tools

Read-only:

• jenkins_whoami
• jenkins_version
• jenkins_health
• jenkins_get_json
• jenkins_list_jobs
• jenkins_get_job
• jenkins_get_job_config
• jenkins_list_builds
• jenkins_get_build
• jenkins_get_build_log
• jenkins_get_build_artifacts
• jenkins_get_test_report
• jenkins_list_queue
• jenkins_get_queue_item
• jenkins_list_views
• jenkins_get_view
• jenkins_list_nodes
• jenkins_get_node
• jenkins_list_plugins

Workspace bundle tools, gated by JENKINS_MCP_ENABLE_WORKSPACE_DOWNLOAD=1 and JENKINS_MCP_WORKSPACE_DOWNLOAD_DIR:

• jenkins_start_workspace_bundle_download
• jenkins_get_workspace_bundle_status
• jenkins_cancel_workspace_bundle_download

Write tools, gated by JENKINS_MCP_ENABLE_WRITES=1:

• jenkins_trigger_build
• jenkins_trigger_build_with_parameters
• jenkins_stop_build
• jenkins_cancel_queue_item
• jenkins_enable_job
• jenkins_disable_job

Optional job config tools, gated by JENKINS_MCP_ENABLE_WRITES=1 and JENKINS_MCP_ENABLE_JOB_CONFIG_WRITE=1:

• jenkins_create_job
• jenkins_copy_job
• jenkins_update_job_config

Delete additionally requires JENKINS_MCP_ENABLE_DELETE=1:

• jenkins_delete_job

Safety

• Read-only by default.
• Write tools require explicit local env flags and Jenkins-side permissions.
• Workspace bundle downloads require a separate explicit env flag and output directory.
• Jenkins logs and job output are treated as untrusted text.
• Jenkins workspace files are treated as untrusted local files.
• API tokens and Authorization headers are not printed by server helpers.
• 401, 403, 404, crumb failures, and permission failures return structured errors.

Limitations

• No script console.
• No restart, safe restart, or quiet down.
• No plugin install/update.
• No credential read/write.
• No node creation/deletion.
• No global config changes.
• No user management.
• jenkins_get_test_report depends on a test-report plugin such as JUnit exposing testReport; it fails clearly if absent.
• Nested folder paths are URL-encoded as repeated job/<segment> path components. Controllers without the needed folder/job type return Jenkins 404s.
• Workspace bundle downloads use Jenkins' job-level workspace endpoint. The saved console log is build-run-specific, but the workspace is the current/some available job workspace and may not be an immutable snapshot of that build.
• Workspace bundle operations stream to disk and report status/progress through jenkins_get_workspace_bundle_status; large downloads can still stress Jenkins controllers or agents.

Testing

Normal tests are mocked and do not require a live Jenkins controller:

python -m pytest
python -m compileall src
ruff check

Optional integration tests only run when all are set:

export JENKINS_INTEGRATION_TESTS=1
export JENKINS_URL="https://jenkins.example.com/"
export JENKINS_USER="your-user"
export JENKINS_API_TOKEN="your-api-token"
python -m pytest tests/test_integration.py

Evidence Docs

• docs/source-truth.md
• docs/source-skills-check.md
• docs/existing-research.md
• docs/architecture-decision.md
• docs/tool-evidence.md
• docs/security.md