Short answer
Claude Desktop reads MCP server definitions from a local JSON config file. The current MCP quickstart documents the config paths on macOS and Windows and uses the same mcpServers structure that other clients use.
The most common failure is not the JSON itself. It is a bad executable path, especially on macOS setups where the GUI app does not inherit the same shell environment as your terminal.
Recommended path
- 01
Open the Claude Desktop config file
On macOS the file is ~/Library/Application Support/Claude/claude_desktop_config.json. On Windows it is %APPDATA%\Claude\claude_desktop_config.json.
- 02
Add the MCP server definition
Use the mcpServers object with a command and args, then save the file.
- 03
Restart Claude Desktop and inspect the tool list
If the tools do not appear, check the executable path first, not just the JSON syntax.
Minimal config example
{
"mcpServers": {
"aescut": {
"command": "npx",
"args": ["-y", "@aeptus/aescut", "--skip-install"]
}
}
}Why npx fails for some users
The official MCP quickstart explicitly warns about environments that use NVM or other shell-specific Node setups. A desktop app can see a different PATH than your terminal, so npx works in Terminal but fails in Claude Desktop.
When that happens, use the absolute path to the executable, or install Node in a way the desktop app can resolve consistently.
When Claude Desktop is the right place to install
Claude Desktop is a good fit for personal, cross-project tools. If the MCP server should travel with one repository and one team, Claude Code or another project-scoped client is often a better fit because the configuration lives closer to the codebase.
Sources and further reading
Related questions
Installation
How do I install an MCP server on Claude Code?
Current Claude Code MCP setup, config locations, CLI shortcuts, and common verification steps.
Aescut MCP
How do I install the Aescut MCP server?
What the Aescut installer actually does today, when to use the generic bundle, and how to wire the MCP manually.
Skills And MCP Basics
What is an MCP server?
Understand what MCP servers are, what transports they use, and why agents rely on them for live tools.