Jamovi

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A local stdio MCP server that lets Claude, Cursor, and other MCP clients control jamovi.

Open datasets, inspect schemas, edit cells, run statistical analyses, export results, and save .omv files through a local jamovi engine.

Fastest Setup

Copy this into your MCP client config:

{
  "mcpServers": {
    "jamovi": {
      "command": "uvx",
      "args": [
        "--from",
        "git+https://github.com/yjm110517/jamovi-mcp.git",
        "jamovi-mcp"
      ]
    }
  }
}

Restart your MCP client, then call jamovi_open with an absolute local data file path.

This is the recommended setup for normal users. You do not need to clone this repository, install a local lib/ directory, or hardcode a machine-specific Python path.

Requirements

• Windows
• jamovi installed locally
• uvx available to the MCP client
• A Python 3.12+ runtime available through uvx or your local Python setup

uvx is part of uv, a Python tool runner. In this README it is used so your MCP client can download and run jamovi-mcp from GitHub without cloning the repository or hardcoding a local Python path.

Install uv on Windows:

winget install astral-sh.uv

jamovi itself is required because this MCP starts a local jamovi engine process. Python does not need to be installed in any specific directory.

jamovi Version Discovery

By default, no JAMOVI_HOME configuration is required. The server scans standard Windows install locations such as Program Files and uses the newest valid jamovi* installation it finds.

Only set JAMOVI_HOME when jamovi is installed in a non-standard location or when you want to pin a specific version:

{
  "mcpServers": {
    "jamovi": {
      "command": "uvx",
      "args": [
        "--from",
        "git+https://github.com/yjm110517/jamovi-mcp.git",
        "jamovi-mcp"
      ],
      "env": {
        "JAMOVI_HOME": "C:\\Path\\To\\jamovi"
      }
    }
  }
}

JAMOVI_HOME must point to the jamovi installation directory that contains Frameworks and Resources.

Example Workflow

You can ask your MCP client to:

Open survey.csv, show the variables, read the first 10 rows, run a t-test, and save the project as analysis.omv.

Typical tool sequence:

1. jamovi_open
2. jamovi_get_schema
3. jamovi_get_data
4. jamovi_run_analysis
5. jamovi_save

MCP Tools

This server exposes 10 MCP tools.

Tool	Purpose	Main arguments
jamovi_open	Open a local data file in jamovi.	file_path
jamovi_get_schema	Read dataset metadata, columns, types, levels, and row counts.	None
jamovi_get_data	Read a rectangular data range as row-major JSON rows.	row_start, row_count, column_start, column_count
jamovi_set_data	Set one dataset cell.	row, column, value
jamovi_list_analyses	List analyses discovered from installed jamovi modules.	None
jamovi_get_analysis_options	Read the option schema for one analysis.	ns, name
jamovi_run_analysis	Run an analysis against the active dataset.	ns, name, options, analysis_id
jamovi_get_analysis	Fetch results for a previously run analysis.	analysis_id
jamovi_export_results	Export analysis results as text or HTML.	analysis_id, fmt
jamovi_save	Save the active dataset as an .omv file.	file_path, overwrite

Usage Examples

Open a CSV file:

{
  "file_path": "C:\\Users\\you\\data\\example.csv"
}

Read the active dataset schema:

{}

Read the first 10 rows and first 3 columns:

{
  "row_start": 0,
  "row_count": 10,
  "column_start": 0,
  "column_count": 3
}

Set a single cell value:

{
  "row": 0,
  "column": 1,
  "value": 10
}

Save the active dataset:

{
  "file_path": "C:\\Users\\you\\data\\output.omv",
  "overwrite": true
}

Run an analysis:

{
  "ns": "jmv",
  "name": "ttestIS",
  "options": {
    "vars": ["score"],
    "students": true
  },
  "analysis_id": 2
}

Architecture

flowchart LR
    Client["MCP Client"] --> Stdio["stdio MCP transport"]
    Stdio --> Server["jamovi_mcp.server"]

    Server --> ToolMap["Tool dispatcher"]
    ToolMap --> FileTools["tools.files"]
    ToolMap --> DataTools["tools.data"]
    ToolMap --> AnalysisTools["tools.analysis"]

    FileTools --> Connection["JamoviConnection"]
    DataTools --> Connection
    AnalysisTools --> Connection

    Server --> Engine["EngineManager"]
    Engine --> Config["config.py"]
    Config --> Discovery["JAMOVI_HOME or Program Files discovery"]
    Config --> EnvConf["bin/env.conf parsing"]
    Discovery --> JamoviInstall["Local jamovi installation"]
    EnvConf --> JamoviInstall

    Engine --> JamoviServer["jamovi.server subprocess"]
    JamoviInstall --> JamoviServer

    Connection --> HTTP["HTTP open/save endpoints"]
    Connection --> WS["WebSocket + protobuf coms"]
    HTTP --> JamoviServer
    WS --> JamoviServer

    AnalysisTools --> Registry["analyses.py registry"]
    Registry --> Modules["Resources/modules YAML"]
    Modules --> JamoviInstall

At startup, EngineManager selects a jamovi installation through config.py, builds the process environment from jamovi's own bin/env.conf, and launches jamovi.server. The MCP server connects to that local engine through JamoviConnection. File operations use jamovi's HTTP routes, while dataset and analysis operations use WebSocket messages encoded with the bundled protobuf definitions.

Compatibility

Verified locally:

• Windows
• Python 3.12
• jamovi 2.6.19.0

Designed compatibility:

• Any jamovi installation with the same Frameworks, Resources, bin/env.conf, HTTP routes, WebSocket API, and protobuf message contract.
• Optional version selection through JAMOVI_HOME.
• Automatic newest-version selection when multiple jamovi* directories are installed under standard Program Files locations.

Known limitation:

• If a future jamovi release changes jamovi.proto, the WebSocket request types, or the HTTP open/save routes, this MCP may need an adapter update and regenerated protobuf code.

Troubleshooting

uvx is not found

Install uv so your MCP client can run uvx, then restart the MCP client:

winget install astral-sh.uv

uvx means "run a Python tool through uv". If you do not want to use uvx, use the development install below and configure the installed jamovi-mcp command instead.

jamovi-mcp requires Python 3.12 or newer

Your MCP client is using an older Python runtime. With uvx, make sure uv can use Python 3.12+. If you manage Python yourself, point the MCP command to a Python 3.12+ executable:

{
  "command": "C:\\Path\\To\\Python\\python.exe",
  "args": ["-m", "jamovi_mcp"]
}

This is an advanced fallback. It is not the recommended setup and the path will differ on every computer.

Invalid JAMOVI_HOME

JAMOVI_HOME must point to the jamovi installation directory that contains Frameworks and Resources.

Example:

{
  "env": {
    "JAMOVI_HOME": "C:\\Path\\To\\jamovi"
  }
}

jamovi is installed but not detected

Set JAMOVI_HOME explicitly in the MCP client config. This is also recommended when testing a specific jamovi version.

File open or save fails

Use absolute Windows paths and make sure the user running the MCP client has permission to read or write that location. For save operations, pass "overwrite": true if the target file already exists.

Analysis tools return unexpected results

First call jamovi_list_analyses, then jamovi_get_analysis_options for the target analysis. jamovi analysis option schemas are module-specific and can differ between versions or installed modules.

Development Install

Normal users should use the uvx MCP config above. Clone the repository only if you want to develop or test the code locally.

git clone https://github.com/yjm110517/jamovi-mcp.git
cd jamovi-mcp
py -3.12 -m pip install -e .

If your system does not have the Windows Python launcher, use any Python 3.12+ executable instead:

python -m pip install -e .

Run tests:

py -3.12 -m pytest -q

Start the MCP server directly:

py -3.12 -m jamovi_mcp

Important source areas:

• src/jamovi_mcp/server.py: MCP server and tool registration.
• src/jamovi_mcp/engine.py: jamovi engine subprocess lifecycle.
• src/jamovi_mcp/config.py: jamovi install discovery and environment setup.
• src/jamovi_mcp/connection.py: HTTP, WebSocket, and protobuf communication.
• src/jamovi_mcp/tools/: MCP tool implementations.
• src/jamovi_mcp/analyses.py: analysis registry built from jamovi module YAML files.
• tests/: unit tests for data conversion, save handling, config, and engine env setup.

Do not commit lib/ or other local dependency target directories. Install dependencies through pyproject.toml.

Security Notes

This MCP starts a local jamovi process and reads or writes local files whose paths are provided through MCP tool calls.

• The engine is started locally and connected through 127.0.0.1.
• File paths are supplied by the MCP client/user.
• Do not expose this server to untrusted clients.
• Do not pass sensitive data files to an MCP client you do not trust.
• Do not commit private local config, access tokens, API keys, or datasets.

Roadmap

• Add GitHub Actions CI.
• Add broader integration tests across more jamovi versions.
• Improve structured parsing for analysis result payloads.
• Add more explicit typed response schemas for each MCP tool.
• Document common jamovi analysis recipes.

Contributing

Pull requests are welcome. Please keep changes focused, run the test suite before submitting, and include tests for behavior changes.

For compatibility work, include the jamovi version, Windows version, and Python version used for testing.

Repository Contents

Files that should be committed:

• README.md
• README.zh-CN.md
• LICENSE
• .gitignore
• pyproject.toml
• docs/
• src/
• tests/

Files and directories that should not be committed:

• lib/
• .pytest_cache/
• .ruff_cache/
• __pycache__/
• local CSV/OMV/log/tmp files
• private local config, tokens, and API keys

License

MIT