If you are experimenting with Model Context Protocol (MCP) servers using AI clients like Claude Desktop, Cursor, or terminal agents, you've probably hit this friction point: managing the configuration file.
Adding a new local or remote server usually means:
- Hunting down the hidden
mcp_config.jsonfile (which lives in entirely different directories depending on your OS and the client you use). - Manually editing a deeply nested JSON structure.
It sounds simple until you miss a comma, leave a trailing comma, or break a bracket, and suddenly your AI client crashes or fails to boot.
I got tired of breaking my configs, so I built a tiny utility to handle it straight from the terminal.
Enter agmcp
agmcp is a CLI manager written in pure Go that safely reads, patches, and writes deeply nested JSON configurations without destroying existing keys or breaking your client apps with syntax errors.
Here is a demo of how agmcp works:
Why build this?
There are package managers for everything, but MCP configs are uniquely annoying because they are just raw JSON files sitting in arbitrary system paths. I wanted a tool that was:
-
Blazing Fast & Lightweight: Written in Go using strictly the standard library (
encoding/json,os,path/filepath). Absolutely no CGO. - Safe: It performs safe JSON patching. It won't overwrite or format over other custom settings your client might have saved in the file.
- Frictionless: It cross-compiles for Linux and Windows, with native install scripts that handle OS-level PATH injection automatically.
Usage
Once installed, you don't even need to know where the config file is. You just run:
# Add a GitHub MCP server
agmcp add github npx -y @modelcontextprotocol/server-github
# Remove a server
agmcp remove github
# List active servers
agmcp list
Try it out
If you are testing a lot of servers locally, give it a try. It is entirely open-source, and I'd love to get feedback from other developers on the Go architecture or the JSON patching approach.
GitHub Repository: https://github.com/simplychiragk/agmcp
Let me know what you think or if you run into any edge cases with specific MCP clients!