openl-mcp-server

Model Context Protocol server for OpenL Studio — the open-source Business Rules Management System.

Exposes OpenL Studio repositories, projects, rules tables, tests, and deployments as MCP tools and expert-guidance prompts, so Claude Desktop, Cursor, and any other MCP-compatible client can manage rules end-to-end.

Install

Run ad-hoc with npx (recommended for MCP clients):

npx -y openl-mcp-server

Or install globally:

npm install -g openl-mcp-server
openl-mcp

Requirements: Node.js ≥ 24.

Configure

The server talks to an OpenL Studio instance over HTTP. Configure it with environment variables:

# Required
OPENL_BASE_URL=<your-openl-studio-host>

# Auth — pick one
OPENL_USERNAME=<your-username>
OPENL_PASSWORD=<your-password>
# …or Personal Access Token
OPENL_PERSONAL_ACCESS_TOKEN=<your-token>

# Optional
OPENL_TIMEOUT=60000

Full auth guide: Authentication.

Use with Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "openl": {
      "command": "npx",
      "args": ["-y", "openl-mcp-server"],
      "env": {
        "OPENL_BASE_URL": "<your-openl-studio-host>",
        "OPENL_PERSONAL_ACCESS_TOKEN": "<your-token>"
      }
    }
  }
}

For Cursor and other clients, see the MCP Connection Guide.

Use as a CLI (direct API calls, no MCP client)

The same binary can invoke any openl_* tool directly from the shell — useful for scripting, CI, and ad-hoc debugging without setting up an MCP client. CLI mode is agent-first: output defaults to markdown (LLM-friendly, same as the MCP server); pass response_format: "json" when you want to pipe into jq.

# Quick discovery (no config needed)
npx -y openl-mcp-server --help          # human catalog (tool titles)
npx -y openl-mcp-server --list-tools    # machine-readable JSON (name/title/schema)

# Single call (markdown by default)
OPENL_BASE_URL=<host> OPENL_PERSONAL_ACCESS_TOKEN=<pat> \
  npx -y openl-mcp-server openl_list_repositories

# JSON for jq pipelines
OPENL_BASE_URL=<host> OPENL_PERSONAL_ACCESS_TOKEN=<pat> \
  npx -y openl-mcp-server openl_list_repositories '{"response_format":"json"}' | jq

See README.cli.md for the full CLI guide: configuration, all flags (--base-url, --token, --user, --password, --timeout, --client-document-id, --cookie-jar), argument-passing modes (@file.json, --stdin), session handling for trace flows, recipes, exit codes, Windows notes, and troubleshooting.

When run without arguments the binary keeps its default behavior and starts the MCP server on stdio.

What you get

• 25 active tools for repositories, projects, rules tables, tests, and deployments (all prefixed openl_)
• 15 expert-guidance prompts (create_rule, deploy_project, run_test, …) for complex OpenL Studio workflows
• Type-safe validation via Zod schemas
• Multiple response formats — json, markdown, markdown_concise, markdown_detailed

Details and tool reference: Usage Examples.

Alternatives

Prefer containers? The same server is published as a Docker image:

• Docker Hub — docker pull openltablets/openl-mcp:<X.Y.Z> (tagged releases) or :latest
• GitHub Container Registry — docker pull ghcr.io/openl-tablets/openl-mcp:latest (nightly edge build, no tagged releases)

See the Docker setup guide.

Links

• Source & issues: https://github.com/openl-tablets/openl-mcp
• OpenL Studio: https://openl-tablets.org/
• MCP spec: https://modelcontextprotocol.io/

License

LGPL-3.0 — follows the OpenL Studio project license.