HoloViz MCP Server

What is DataViz MCP?

DataViz MCP connects an AI assistant to a local Panel server. The assistant can inspect data, generate Python visualization code, validate it, render it as an interactive web page, review the result in a browser, and refine it before sharing the final visualization.

It supports two complementary workflows:

• MCP mode: create and inspect visualizations from VS Code, Cursor, Claude, and other MCP clients.

• Standalone mode: submit, browse, edit, and publish visualizations from a local web interface.

AI-assisted visualization

Standalone visualization workspace

Related MCP server: Chart-Output MCP Server

Why DataViz MCP?

How it works

flowchart LR
    U[User request] --> A[AI assistant]
    A --> M[DataViz MCP server]
    M --> V{Request type}
    V -->|Inspect data| L[load_data]
    V -->|Render code| S[show]
    V -->|Review output| C[screenshot]
    V -->|Text result| E[evaluate]
    L --> P[Profile and select strategy]
    P --> R[Panel rendering service]
    S --> Q[Validation pipeline]
    Q --> R
    R --> B[Interactive browser view]
    C --> B
    R --> D[(SQLite snippets)]

The MCP process coordinates tools and validation. A separate Panel process renders the visual output, while SQLite stores snippets and their publication state.

Automatic data strategy

flowchart TD
    A[Local path or remote URL] --> B[Inspect format and metadata]
    B --> C{Dataset shape}
    C -->|Large or dense| D[Datashader-backed hvPlot]
    C -->|Multidimensional| E[HoloViews or Xarray]
    C -->|Ordinary tabular data| F[hvPlot]
    D --> G[Interactive Panel view]
    E --> G
    F --> G

Source location and data shape are treated separately. A remote dataset can still be simple, multidimensional, or large.

Quick start

1. Install

Python 3.12 or later is required. The pydata extra installs the broad visualization stack.

uv tool install "dataviz-mcp[pydata]"
pls install-browser
pls --version

You can also use pip inside a virtual environment:

python -m venv .venv
source .venv/bin/activate
pip install "dataviz-mcp[pydata]"
pls install-browser

Windows PowerShell activation:

python -m venv .venv
.venv\Scripts\Activate.ps1
pip install "dataviz-mcp[pydata]"
pls install-browser

See the complete installation guide for pixi, uv, pip, Windows, and environment-specific instructions.

2. Connect an MCP client

DataViz MCP can add its configuration without replacing your other MCP servers:

pls install vscode

Other supported targets include:

pls install cursor
pls install claude-desktop
pls install windsurf
pls install cline
pls install gemini
pls install kiro
pls install copilot

For manual VS Code configuration, find the executable first:

which pls

Then create .vscode/mcp.json:

{
  "servers": {
    "dataviz-mcp": {
      "type": "stdio",
      "command": "/absolute/path/to/pls",
      "args": ["mcp"]
    }
  }
}

Always use the absolute executable path. Restart the MCP connection after changing the package or local server code.

3. Ask for a visualization

Try a direct request in your MCP client:

Create an interactive scatter plot that compares departure delay with arrival delay. Use Datashader if the dataset is large and explain the visible pattern.

Or inspect data without creating a chart:

Analyze this dataset, summarize its structure and quality, and recommend useful visualizations without creating a plot yet.

MCP tools

The packaged dataviz-plot-selection skill guides chart choice, renderer selection, visual integrity, and screenshot review. Its guidance is included in the MCP server instructions automatically.

Data support

load_data accepts local paths and HTTP(S) URLs for:

• CSV

• JSON

• JSONL and NDJSON

• Parquet

• NetCDF (.nc)

The tool counts or estimates rows before retaining data, profiles large inputs from a bounded sample, and reports the full detected shape separately from the sample size. Use visualize=False to return schema, missing values, duplicate counts, descriptive statistics, preview records, and chart recommendations without creating a visualization.

Run from the terminal

Start the standalone server:

pls serve

Start the stdio MCP server:

pls mcp

Check the local Panel service:

pls status

The longer dataviz-mcp command is also available, but pls is easier to type.

Visual review workflow

sequenceDiagram
    participant U as User
    participant A as AI assistant
    participant M as DataViz MCP
    participant P as Panel server
    U->>A: Request a visualization
    A->>M: screenshot(code)
    M->>P: Validate and render private draft
    P-->>A: Screenshot and diagnostics
    A->>M: edit(draft_id) when needed
    A->>M: show(draft_id)
    M->>P: Publish reviewed result
    P-->>U: Interactive visualization URL

This workflow separates visual checking from publication. A draft can be revised without exposing an unfinished result in the public feed.

Security

DataViz MCP executes Python supplied by a user or AI assistant with the privileges of the account that started the process. Validation is a guardrail, not a sandbox.

• Run it only in an environment where you are comfortable executing the submitted code.

• Do not expose the local service port to an untrusted network.

• Review generated code when it accesses files, credentials, or external services.

• Use an isolated virtual environment for demonstrations and development.

Documentation

• Installation

• MCP server tutorial

• Standalone server tutorial

• Examples

• Architecture

• Server configuration

Development

Clone the project and install the development environment:

git clone https://github.com/SuMayaBee/DataViz-MCP.git
cd DataViz-MCP
pixi install
pixi run postinstall
pixi run test

See the contributing guide for environment setup, testing, linting, documentation, and pull request guidance.

Contributing

Contributions, bug reports, documentation improvements, and visualization examples are welcome.

1. Fork the repository.

2. Create a focused branch.

3. Add the change and its tests or documentation.

4. Run the test and lint tasks.

5. Open a pull request with a clear explanation and screenshots when the UI changes.

License

See the repository license for usage and redistribution terms.