# Got a .moca file? Ask your AI assistant about it > Open a MOCA knowledge package in Claude Desktop, Claude Code, VS Code or Cursor with one download, check who published it, and get answers that cite their source. Source: https://openmoca.org/start/open-a-package/ 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](https://modelcontextprotocol.io) (MCP), such as Claude Desktop, Claude Code, VS Code and Cursor. It runs on your computer, and makes no network calls. [Download moca-mcp](https://github.com/openmoca/moca-mcp-dotnet/releases/latest) 1. **Download the server for your computer** from the [latest release](https://github.com/openmoca/moca-mcp-dotnet/releases/latest), and unzip it somewhere you will keep it: | Computer | File | | | --- | --- | --- | | Windows | `moca-mcp-win-x64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-win-x64.zip) | | Windows on Arm | `moca-mcp-win-arm64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-win-arm64.zip) | | Mac with Apple silicon | `moca-mcp-osx-arm64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-osx-arm64.zip) | | Mac with an Intel processor | `moca-mcp-osx-x64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-osx-x64.zip) | | Linux | `moca-mcp-linux-x64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-linux-x64.zip) | | Linux on Arm | `moca-mcp-linux-arm64.zip` | [Download](https://github.com/openmoca/moca-mcp-dotnet/releases/latest/download/moca-mcp-linux-arm64.zip) | 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**. 2. **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](/docs/guides/consuming/#your-trust-root)). 3. **Connect it to your assistant**, as below. Use the full paths to the files. 4. **Ask.** For example: "Using the acme-support package, how long do customers have to ask for a refund? Cite the page." ## Connect it **Claude Desktop:** 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: ```json { "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](#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 Code:** ```sh 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. **VS Code:** In `.vscode/mcp.json`, or with **MCP: Add Server** from the Command Palette: ```json { "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. **Cursor:** In `~/.cursor/mcp.json` for every project, or `.cursor/mcp.json` in one: ```json { "mcpServers": { "acme-support": { "command": "/Users/you/moca/moca-mcp", "args": ["/Users/you/moca/acme-support.moca", "--trust-root", "/Users/you/moca/trust-root.json"] } } } ``` **Other clients:** Any MCP client that starts local (stdio) servers takes the same command and arguments. Several packages can share one server: list them all. **ChatGPT and Claude.ai on the web** cannot reach a server on your computer. They call MCP servers from their own cloud, so they need a hosted MCP server with a public address. ## Several packages Keep them in one folder, packed (`.moca`) or unpacked, and serve the folder instead of naming each package: ```sh moca-mcp --library /Users/you/moca --trust-root /Users/you/moca/trust-root.json ``` In Claude Desktop's `claude_desktop_config.json`, that is: ```json { "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: ```sh 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](/docs/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](https://github.com/openmoca/moca-spec/releases/latest/download/acme-support.moca) and its [trust root](https://github.com/openmoca/moca-spec/releases/latest/download/example-trust-root.json): 34 pages in English and French, signed and reviewed. Or search it in your browser at [Try OpenMOCA](https://try.openmoca.org/p/support-kb). ## 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. ## Next - [Use MOCA with your AI assistant](/start/ai-assistant/): the agent skill, to make and sign packages of your own. - [MCP server](/tools/mcp/): every option. - [Walkthrough](/docs/walkthrough/): make, sign, index and serve a package, step by step.