Got a .moca file? Ask your AI assistant about it

Someone has sent you a .moca file: a knowledge package, such as a product’s documentation, a policy set or a support knowledge base. You want to ask your AI assistant about it, and get answers that say where they came from.

The MOCA MCP server does that. It is one download with nothing else to install. It connects the package to any assistant that supports the Model Context Protocol (MCP), such as Claude Desktop, Claude Code, VS Code and Cursor. It runs on your computer, and makes no network calls.

Download moca-mcp

Download the server for your computer from the latest release, and unzip it somewhere you will keep it:

Computer	File
Windows	`moca-mcp-win-x64.zip`	Download
Windows on Arm	`moca-mcp-win-arm64.zip`	Download
Mac with Apple silicon	`moca-mcp-osx-arm64.zip`	Download
Mac with an Intel processor	`moca-mcp-osx-x64.zip`	Download
Linux	`moca-mcp-linux-x64.zip`	Download
Linux on Arm	`moca-mcp-linux-arm64.zip`	Download

The builds are not code-signed yet, so your computer asks the first time. On a Mac, right-click moca-mcp in Finder, choose Open, then Open again. On Windows, choose More info, then Run anyway.

Put the package somewhere you will keep it, with its trust root if you were given one. The trust root (trust-root.json) lists the publishers you trust. Without it the server still works, but cannot tell you who signed the package (your trust root).
Connect it to your assistant, as below. Use the full paths to the files.
Ask. For example: “Using the acme-support package, how long do customers have to ask for a refund? Cite the page.”

Connect it

Go to Settings, then Extensions (under Desktop app). At the bottom of that page, choose Manage, then Edit Config under Local MCP servers. That opens claude_desktop_config.json (in ~/Library/Application Support/Claude/ on a Mac, %APPDATA%\Claude\ on Windows). Add the server, save, and quit and restart Claude:

{
  "mcpServers": {
    "acme-support": {
      "command": "/Users/you/moca/moca-mcp",
      "args": ["/Users/you/moca/acme-support.moca",
               "--trust-root", "/Users/you/moca/trust-root.json",
               "--audience", "public"]
    }
  }
}

If the file has no mcpServers yet, add it as shown, inside the outer { } and beside any settings already there, with a comma between them. For a folder of packages, see Several packages.

On Windows, the command is moca-mcp.exe, and each \ in a path is written twice: "C:\\Users\\you\\moca\\moca-mcp.exe".

claude mcp add acme-support -- /Users/you/moca/moca-mcp \
  /Users/you/moca/acme-support.moca --trust-root /Users/you/moca/trust-root.json

Add --scope project to share it with everyone working in the repository.

In .vscode/mcp.json, or with MCP: Add Server from the Command Palette:

{
  "servers": {
    "acme-support": {
      "type": "stdio",
      "command": "/Users/you/moca/moca-mcp",
      "args": ["/Users/you/moca/acme-support.moca",
               "--trust-root", "/Users/you/moca/trust-root.json"]
    }
  }
}

Then use it from Copilot Chat in agent mode.

In ~/.cursor/mcp.json for every project, or .cursor/mcp.json in one:

{
  "mcpServers": {
    "acme-support": {
      "command": "/Users/you/moca/moca-mcp",
      "args": ["/Users/you/moca/acme-support.moca",
               "--trust-root", "/Users/you/moca/trust-root.json"]
    }
  }
}

Several packages

Keep them in one folder, packed (.moca) or unpacked, and serve the folder instead of naming each package:

moca-mcp --library /Users/you/moca --trust-root /Users/you/moca/trust-root.json

In Claude Desktop’s claude_desktop_config.json, that is:

{
  "mcpServers": {
    "moca": {
      "command": "/Users/you/moca/moca-mcp",
      "args": ["--library", "/Users/you/moca",
               "--trust-root", "/Users/you/moca/trust-root.json",
               "--audience", "public"]
    }
  }
}

The server reads only each package’s manifest when it starts, and loads a package the first time a question needs it. Ask about one at a time, for example “Using the acme-support package, …”: the assistant lists the packages and searches the ones you name. Add --watch to pick up packages you add while it runs.

Search by meaning

Out of the box the server searches by words. Install one of the standard embedding models and it also searches by meaning, so a question finds the page that answers it even when they share no words:

moca-mcp models add bge-small-en-v1.5

This works for packages that come with an index built with the same model (acme-support.moca.idx beside acme-support.moca). The assistant can list the packages to see which model each needs; bge-small-en-v1.5 (33 MB, English) is a good default, and multilingual-e5-small covers many languages.

Check what you are reading

Ask the assistant to list the MOCA packages. For each one, the server reports its version, its digest, and whether a publisher in your trust root signed it. If you expected a signature and it says signed: false, check the trust root path, or ask the sender for theirs.

Every answer the server gives is a citation record: the text, the page it came from and its version, and whether quoted evidence was found in the original source. Out-of-date and superseded pages are left out unless you ask for them. See trust and provenance.

--audience public keeps internal pages out of every answer. The assistant cannot widen it.

Try it now

No package of your own yet? Download the Acme support example and its trust root: 34 pages in English and French, signed and reviewed. Or search it in your browser at Try OpenMOCA.

Privacy

The server reads only the files you name. It has no telemetry, sends nothing anywhere, and keeps no record of your questions. The one command that downloads is moca-mcp models add, which fetches the model you ask for and checks it against its pinned SHA-256. What your assistant does with the text it receives is governed by the assistant’s own terms.

Use MOCA with your AI assistant: the agent skill, to make and sign packages of your own.
MCP server: every option.
Walkthrough: make, sign, index and serve a package, step by step.