Gretl MCP Server

Gretl MCP

Built for AI agents: run Hansl/Gretl workflows, get graph screenshots, and view calculations in the real Gretl GUI.

It lets MCP clients run Gretl/Hansl scripts, raw Gretl command lines, existing .inp files, package operations, package builds, help lookups, dataset summaries, and OLS models. The generic gretl_run_script tool is the main path for prompt-generated Gretl workflows: the client writes Hansl from the user's request, runs it through Gretl, and returns Gretl's output plus generated artifacts.

Keywords: Claude Gretl, MCP econometrics, Hansl AI, Gretl GUI automation.

Key Features

• Scriptable Gretl control through gretlcli.
• GUI-first workflow tools that launch gretl.exe and fail if the GUI did not open.
• Capability discovery for Gretl commands, functions, and package commands.
• Generic execution tools for full Hansl scripts, command lists, and local .inp script files.
• Package tools for pkg and makepkg workflows from the Gretl Function Package Guide.
• High-level tools for version checks, command help, dataset summaries, and OLS.
• Stdio transport, compatible with common MCP clients.
• Safe defaults for arbitrary scripts, with documented escape hatches.

Requirements

• Node.js 20 or newer.
• Gretl 2026b or newer with gretlcli available.
• An MCP client that supports stdio servers.

Getting Started

One-command install (after npm publish):

npx -y gretl-mcp@latest --version

Local install from GitHub:

git clone https://github.com/OndrejLapes/GretlMCP.git
cd GretlMCP
npm install
npm run build

Then point your MCP client at the built server:

{
  "mcpServers": {
    "gretl": {
      "command": "node",
      "args": ["C:\\Users\\YOUR_USER\\GretlMCP\\dist\\index.js"],
      "env": {
        "GRETL_CLI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretlcli.exe",
        "GRETL_GUI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretl.exe"
      }
    }
  }
}

Visual Walkthrough

Forecast output example (actual vs forecast):

Forecast error panel:

Install Gretl

Windows

Download Gretl from the official page: https://gretl.sourceforge.net/win32/

For a no-admin setup, extract the zip archive to:

C:\Users\YOUR_USER\tools\gretl

Verify:

& C:\Users\YOUR_USER\tools\gretl\gretlcli.exe --version

macOS

Install via Homebrew (if available on your setup) or the Gretl project site:

brew install gretl
gretlcli --version

Linux

Install from your distro packages, then verify:

sudo apt-get install gretl    # Debian/Ubuntu example
gretlcli --version

MCP Client Config

Use this JSON config for stdio MCP clients:

{
  "mcpServers": {
    "gretl": {
      "command": "node",
      "args": ["C:\\Users\\YOUR_USER\\GretlMCP\\dist\\index.js"],
      "env": {
        "GRETL_CLI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretlcli.exe",
        "GRETL_GUI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretl.exe"
      }
    }
  }
}

After npm publication, the standard MCP config is:

{
  "mcpServers": {
    "gretl": {
      "command": "npx",
      "args": ["-y", "gretl-mcp@latest"],
      "env": {
        "GRETL_CLI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretlcli.exe",
        "GRETL_GUI": "C:\\Users\\YOUR_USER\\tools\\gretl\\gretl.exe"
      }
    }
  }
}

Client Setup

Claude Code

Local GitHub build:

claude mcp add gretl node C:\Users\YOUR_USER\GretlMCP\dist\index.js

npm install path:

claude mcp add gretl npx -y gretl-mcp@latest

Codex

Local GitHub build:

[mcp_servers.gretl]
command = "node"
args = ["C:\\Users\\YOUR_USER\\GretlMCP\\dist\\index.js"]

[mcp_servers.gretl.env]
GRETL_CLI = "C:\\Users\\YOUR_USER\\tools\\gretl\\gretlcli.exe"
GRETL_GUI = "C:\\Users\\YOUR_USER\\tools\\gretl\\gretl.exe"

npm install path:

[mcp_servers.gretl]
command = "npx"
args = ["-y", "gretl-mcp@latest"]

[mcp_servers.gretl.env]
GRETL_CLI = "C:\\Users\\YOUR_USER\\tools\\gretl\\gretlcli.exe"
GRETL_GUI = "C:\\Users\\YOUR_USER\\tools\\gretl\\gretl.exe"

Cursor, Windsurf, Cline, and similar clients

Use the local JSON config above. If the client asks for a command and args separately, use:

command: node
args: C:\Users\YOUR_USER\GretlMCP\dist\index.js

VS Code

code --add-mcp "{\"name\":\"gretl\",\"command\":\"node\",\"args\":[\"C:\\\\Users\\\\YOUR_USER\\\\GretlMCP\\\\dist\\\\index.js\"],\"env\":{\"GRETL_CLI\":\"C:\\\\Users\\\\YOUR_USER\\\\tools\\\\gretl\\\\gretlcli.exe\",\"GRETL_GUI\":\"C:\\\\Users\\\\YOUR_USER\\\\tools\\\\gretl\\\\gretl.exe\"}}"

Try It Quickly

Ask your agent:

Run a Gretl forecasting dashboard with AR, ARIMA, and VAR. Save plots and compare RMSE/MAE.

The MCP response includes generated artifact paths, workspace/script paths, and GUI launch details.

Configuration

gretl-mcp supports environment variables and CLI flags.

Environment variables:

• GRETL_CLI: optional path to gretlcli or gretlcli.exe.
• GRETL_GUI: optional path to gretl or gretl.exe.
• GRETLMCP_WORKSPACE_DIR: optional directory for Gretl run workspaces.
• GRETLMCP_OPEN_GUI: set to false to stop tools from opening Gretl windows by default.
• GRETLMCP_REQUIRE_GUI: set to false to allow CLI-only success when GUI opening is disabled or unavailable.
• GRETLMCP_ENFORCE_GUI_ONLY: set to true to reject any headless workflow request.

CLI options:

gretl-mcp --gretl-cli C:\Users\YOUR_USER\tools\gretl\gretlcli.exe
gretl-mcp --gretl-gui C:\Users\YOUR_USER\tools\gretl\gretl.exe
gretl-mcp --workspace C:\Users\YOUR_USER\gretl-mcp-runs
gretl-mcp --enforce-gui-only
gretl-mcp --allow-headless
gretl-mcp --help
gretl-mcp --version

Tools

• gretl_version: checks Gretl availability.
• gretl_gui_version: checks Gretl GUI availability.
• gretl_gui_launch: launches the visible Gretl desktop GUI.
• gretl_capabilities: lists installed Gretl commands, functions, and package help.
• gretl_run_script: runs a Gretl/Hansl script and requires GUI opening by default.
• gretl_run_commands: runs raw Gretl command lines and requires GUI opening by default.
• gretl_run_script_file: runs an existing local .inp file and requires GUI opening by default.
• gretl_package: runs native pkg actions such as install, query, run-sample, unload, remove, and index.
• gretl_make_package: builds .gfn or .zip function packages with makepkg.
• gretl_help: returns Gretl help for a command.
• gretl_dataset_summary: opens a local dataset, returns summary statistics, and requires GUI opening by default.
• gretl_ols: opens a local dataset, estimates an OLS model, and requires GUI opening by default.

Safety

gretl_run_script, gretl_run_commands, and gretl_run_script_file default to safeMode: true, which blocks common shell-like commands and absolute file reads/writes. This is a guardrail, not a complete sandbox. Use safeMode: false only for trusted local work.

Dataset helper tools reject URLs and require paths to existing local files.

Examples

• examples/homework-variance-ftest.inp: Gretl script for a homework-style F test with critical-value and p-value calculations.
• examples/forecasting-dashboard.inp: Macro forecasting dashboard with AR, ARIMA, VAR, forecast plots, and an RMSE/MAE comparison table.
• examples/specification-curve-analysis.inp: 32-model robustness sweep for an education coefficient with curve, confidence bands, and histogram plots.

Use Cases

• Econometrics teaching aid with visible Gretl GUI workflows.
• Textbook replication and assignment automation.
• Forecasting dashboards (AR/ARIMA/VAR) with artifact outputs.
• Monte Carlo and stress-testing workflows for research.
• Reproducible research pipelines via saved scripts and Gretl .inp files.

GUI Mode

By default, the workflow tools open their generated Hansl script in the real Gretl desktop app while also returning structured MCP output. More importantly, they now treat GUI opening as required outside CI. If the Gretl window does not open, the tool returns ok: false even when the CLI script itself succeeded.

Set displayInGretl: false and requireGui: false on a tool call, or set GRETLMCP_OPEN_GUI=false together with GRETLMCP_REQUIRE_GUI=false, to allow CLI-only automation.

For clients that should never bypass the desktop app, set GRETLMCP_ENFORCE_GUI_ONLY=true or launch the server with --enforce-gui-only. In that mode, the workflow tools reject displayInGretl: false and requireGui: false instead of honoring them.

gretl_gui_launch can also be called directly. It starts the real Gretl desktop application, opens a local dataset/script file, or writes a prompted Hansl script and launches Gretl with --run.

This is not full click-by-click GUI control by itself. If you want the agent to observe screenshots, click menus, and make choices exactly like a human, the MCP client also needs desktop automation or computer-use capability. Gretl MCP now provides the Gretl-side launch surface for that workflow.

Local Development

npm install
npm run typecheck
npm test
npm run build
npm run smoke
npm run stress

npm run stress drives the built MCP server through broader prompt-style workflows: macro forecasting, structural breaks, Monte Carlo simulation, textbook replication, diagnostic automation, NLS, mixed-frequency compaction, panel models, GARCH graphs, IV simulation, and a reproducible project. The foreign-language stress case is dependency-gated and requires a real Python, Rscript, or Octave executable on PATH.

To surface stress outputs for docs or QA snapshots:

npm run stress

Then inspect the reported workspace for generated graphs/tables.

Run the built server:

node dist/index.js

Publishing

This project is structured for GitHub, npm, and MCP Registry metadata:

• GitHub hosts source code, issues, docs, releases, and CI.
• npm will provide the easiest user install path after publication.
• server.json is included for registry publish.

Before publishing to npm or the MCP Registry, review docs/publishing.md.

Community

Issues and pull requests are welcome. See CONTRIBUTING.md for contribution flow and expectations.