GroupDocs.Comparison MCP Server

MCP server that exposes GroupDocs.Comparison as AI-callable tools for Claude, Cursor, GitHub Copilot, and other MCP agents.

Installation

One-click installs pre-fill every supported setting: edit the placeholder documents folder after install (output defaults to the same folder); an empty GROUPDOCS_LICENSE_PATH runs in evaluation mode - point it at your license to lift limits.

More clients - ready-made configs for Claude Code, Codex CLI, Visual Studio 2022, Cursor, Windsurf, Cline, and JetBrains Rider live in install/generated/.

Requires .NET 10 SDK.

Run directly with dnx (recommended — no install step):

dnx GroupDocs.Comparison.Mcp --yes

Pulls the latest stable release on every invocation. To pin to a specific version (recommended for shared configs and CI), append @<version>:

dnx GroupDocs.Comparison.Mcp@26.9.0 --yes

Or install as a global dotnet tool:

dotnet tool install -g GroupDocs.Comparison.Mcp
groupdocs-comparison-mcp

Or run via Docker:

docker run --rm -i \
  -v $(pwd)/documents:/data \
  ghcr.io/groupdocs-comparison/comparison-net-mcp:latest

Native prerequisites

The underlying GroupDocs engine uses System.Drawing (GDI+) for some operations. When you run the server natively (via dnx or the global dotnet tool) on Linux or macOS, install the native libgdiplus library first:

Platform	Setup
Windows	Nothing — GDI+ is built into the OS.
Linux	`sudo apt-get install -y libgdiplus libfontconfig1 ttf-mscorefonts-installer`
macOS	`brew install mono-libgdiplus`
Docker	Nothing — the image already bundles `libgdiplus`.

Skipping this on Linux/macOS surfaces as DllNotFoundException: libgdiplus in the tool response. The simplest zero-setup option on Linux/macOS is the Docker image.

Available MCP Tools

Tool	Description
`Compare`	Compares two documents (source vs target) and produces a marked-up result file, plus a change-count summary and a structured JSON list of the changes (type, page, the changed fragment, surrounding source/target text, table cell, style changes). Use when the user wants the rendered diff document. Supports PDF, Word, Excel, PowerPoint, ODT, RTF, TXT, HTML, and 30+ more formats; optional `sourcePassword` / `targetPassword` cover protected documents.
`AnalyzeChanges`	Returns the differences between two documents as structured data only — the same JSON change list as `Compare`, but without rendering or saving a result file. Cheaper than `Compare`; use when the user wants to summarize, explain, or reason about what changed rather than obtain the marked-up file. Optional `sourcePassword` / `targetPassword`.
`GetDocumentInfo`	Inspects a single source document and returns file type, page count, file size, and per-page dimensions as JSON — without performing a comparison. Useful as a pre-flight check before deciding whether to compare or which formats to expect. Optional `password` for protected documents.

Example prompts for AI agents

Once the server is wired up to your MCP client (Claude Desktop, Cursor, VS Code Copilot, …), try:

Compare old.pdf and new.pdf and save the marked-up result.

Diff contract-v1.docx against contract-v2.docx and tell me the change count.

What changed between proposal-v1.docx and proposal-v2.docx? Summarize the edits.

Did the prices change between budget-q1.xlsx and budget-q2.xlsx? Which cells?

How many pages does report.pdf have? Who's the author?

Inspect /docs/legal-brief.pdf — what's the file type and page count?

The client picks Compare when the user wants the rendered diff file, AnalyzeChanges when they only want to know what changed (summary / analysis, no file), and GetDocumentInfo for inspection-only questions.

Licensing

The MCP server itself is MIT; the underlying GroupDocs.Comparison engine requires a license for production use. Without one the server runs in evaluation mode:

Comparison output may carry evaluation watermarks / notices.
A single server process can open at most 15 documents; further calls fail with an evaluation-cap error until the server restarts.

There are two ways to license the server.

License file — point GROUPDOCS_LICENSE_PATH at your GroupDocs.Total.lic. Works offline.

Metered (pay-per-use) — set both GROUPDOCS_METERED_PUBLIC_KEY and GROUPDOCS_METERED_PRIVATE_KEY. You are billed for what you actually process, which suits AI agents well because their usage is bursty and hard to predict up front. If both a metered key pair and a license file are configured, metered wins and the file is ignored.

Metered mode needs outbound connectivity. Usage is reported to GroupDocs servers, so air-gapped or firewalled deployments must allow that egress — or use a license file instead.

Call the get_license_status tool at any time to see which mode is active, and — under metered — the consumed quantity and remaining credit.

Keeping the private key out of your config

The metered private key is a secret. MCP client configs are plain files on disk, and a project-scoped .mcp.json is committed by convention, so prefer, in order:

Set the variables in your OS environment and leave them out of the config entirely. An stdio MCP server inherits its client's environment, so this works in every client. On macOS note that an app launched from Finder does not inherit shell exports — use launchctl setenv, or launch the client from a terminal.
Reference them indirectly if your client supports it (Claude Code expands ${VAR}; VS Code uses ${env:VAR} and ${input:...}).
A literal value in a user-scoped config (for example ~/.claude.json) is acceptable for a single developer.
Never commit a literal key in a project-scoped .mcp.json.

For Docker, forward the values without writing them into any file:

docker run --rm -i   -e GROUPDOCS_METERED_PUBLIC_KEY -e GROUPDOCS_METERED_PRIVATE_KEY   -v /path/to/documents:/data   ghcr.io/groupdocs-comparison/comparison-net-mcp:latest

Configuration

Variable	Description	Default
`GROUPDOCS_MCP_STORAGE_PATH`	Base folder for input and output files	current directory
`GROUPDOCS_MCP_OUTPUT_PATH`	(Optional) separate folder for output files	`GROUPDOCS_MCP_STORAGE_PATH`
`GROUPDOCS_LICENSE_PATH`	Path to GroupDocs license file	(evaluation mode)
`GROUPDOCS_METERED_PUBLIC_KEY`	Metered public key. Requires the private key too; takes precedence over the license file	(unset)
`GROUPDOCS_METERED_PRIVATE_KEY`	Metered private key. Secret - see Licensing	(unset)

Usage with Claude Desktop

{
  "mcpServers": {
    "groupdocs-comparison": {
      "type": "stdio",
      "command": "dnx",
      "args": ["GroupDocs.Comparison.Mcp", "--yes"],
      "env": {
        "GROUPDOCS_MCP_STORAGE_PATH": "/path/to/documents"
      }
    }
  }
}

To pin to a specific version, replace "GroupDocs.Comparison.Mcp" with "GroupDocs.Comparison.Mcp@26.9.0" in args. Pinning is recommended for shared / committed configs to avoid surprise upgrades.

Usage with VS Code / GitHub Copilot

NuGet.org generates a ready-to-use mcp.json snippet on the package page. Copy it directly into your .vscode/mcp.json.

Alternatively, add manually to .vscode/mcp.json:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "storage_path",
      "description": "Base folder for input and output files.",
      "password": false
    }
  ],
  "servers": {
    "groupdocs-comparison": {
      "type": "stdio",
      "command": "dnx",
      "args": ["GroupDocs.Comparison.Mcp", "--yes"],
      "env": {
        "GROUPDOCS_MCP_STORAGE_PATH": "${input:storage_path}"
      }
    }
  }
}

Same pinning rule as above — swap "GroupDocs.Comparison.Mcp" for "GroupDocs.Comparison.Mcp@26.9.0" to lock to a specific release.

Usage with Docker Compose

cd docker
docker compose up

Edit docker/docker-compose.yml to point volumes at your local documents folder.

Documentation & guides

Step-by-step deployment guides and a published-package integration test suite live in the companion repo GroupDocs.Comparison.Mcp.Tests:

Install from NuGet — dnx, global tool, pinned vs always-latest
Run via Docker
Verify on the MCP registry
Use with Claude Desktop
Use with VS Code / GitHub Copilot
Run the integration tests

That repo also exercises every advertised tool against the published NuGet artifact on Linux, macOS, and Windows in CI — so the snippets above are verified end-to-end on every release.

License

MIT — see LICENSE