---
title: "Claude Desktop | Crossmart Docs"
description: "Connect Claude Desktop to Crossmart as a custom connector with OAuth sign-in, or through a local bridge that sends an API key."
url: "https://docs.crossmart.io/agents/claude-desktop/"
---

# Claude Desktop

Checked on 2026-11-06 against [modelcontextprotocol.io: connect local servers](https://modelcontextprotocol.io/docs/develop/connect-local-servers), [claude.com: custom connectors](https://claude.com/docs/connectors/custom/add-unlisted) and the [mcp-remote README](https://github.com/geelen/mcp-remote).

Claude Desktop adds **remote** servers as custom connectors, which sign in with OAuth. Its config file starts **local** (stdio) servers only, so an API key needs a local bridge.

## Sign in with OAuth

Add Crossmart as a custom connector with the URL `https://mcp.crossmart.io/mcp` and choose **Sign in**. Custom connectors are shared by claude.ai, Claude Desktop and the mobile apps; the steps are in the [claude.ai guide](https://docs.crossmart.io/agents/claude-ai/).

## Or connect with an API key

Create a key ([how](https://docs.crossmart.io/agents/#or-use-an-api-key)). The config file opens from **Settings → Developer → Edit Config**:

| OS | Path |
| - | - |
| macOS | `~/Library/Application Support/Claude/claude_desktop_config.json` |
| Windows | `%APPDATA%\Claude\claude_desktop_config.json` |
| Linux | `~/.config/Claude/claude_desktop_config.json` |

[`mcp-remote`](https://github.com/geelen/mcp-remote) is a small open-source stdio proxy that forwards to a remote server and adds headers. It needs Node.js. It is a third-party project, not part of Claude or Crossmart; pin a version you’ve reviewed if your security policy asks for it.

```json
{
  "mcpServers": {
    "crossmart": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://mcp.crossmart.io/mcp",
        "--header",
        "x-api-key:${CROSSMART_API_KEY}"
      ],
      "env": { "CROSSMART_API_KEY": "cm_…" }
    }
  }
}
```

Write `x-api-key:${CROSSMART_API_KEY}` without a space after the colon: the mcp-remote README notes that Claude Desktop on Windows does not escape spaces inside `args`.

You can also run Crossmart’s own local MCP server; see [MCP server → Claude Desktop](https://docs.crossmart.io/developers/mcp/#connect-with-an-api-key).

## Check

Restart Claude Desktop. The tools menu in a new chat lists **crossmart** with its tools.

## Install the skill

Zip the `skills/crossmart` folder (the zip must contain the `crossmart` folder with `SKILL.md` inside), then **Customize → Skills → + → Upload a skill**. Skills need code execution turned on (**Settings → Capabilities**). See [Using skills in Claude](https://support.claude.com/en/articles/12512180-using-skills-in-claude) and [the Crossmart skill](https://docs.crossmart.io/agents/skill/).