mcps.nix

A curated library of MCP (Model Context Protocol) server presets for Claude Code that integrates with native Claude modules in devenv and Home Manager.

Overview

Both devenv and home-manager now have native support for Claude Code configuration:

• home-manager: programs.claude-code
• devenv: claude.code

This project provides reusable MCP server configurations (presets) that work with these native modules, allowing you to easily enable and configure popular MCP servers without manual JSON configuration.

Features

• Pre-configured MCP Servers: Built-in presets for popular MCP servers including Asana, GitHub, Buildkite, Git, Filesystem, LSP integrations, and more

• Secure Credential Management: Support for reading API tokens from files instead of environment variables

• Native Integration: Works with upstream Claude modules in both devenv and home-manager

• Two Home Manager Options: Choose between native integration or custom script-based installation

• Extensible: Add custom MCP servers alongside presets

Quick Start

Add this flake’s overlay to your nixpkgs import.

let
  pkgs = import nixpkgs {
    overlays = [ inputs.mcps.overlays.default ];
  };
in
# ...

Using with devenv

Add to your devenv module configuration:

{
  imports = [ inputs.mcps.devenvModules.claude ];

  claude.code = {
    enable = true;
    mcps = {
      git.enable = true;
      filesystem = {
        enable = true;
        allowedPaths = [ "/path/to/your/project" ];
      };
      github = {
        enable = true;
        tokenFilepath = "/path/to/github-token";
      };
    };
  };
}

Using with Home Manager

This project provides two Home Manager modules:

Option 1: Native Integration (Recommended)

Integrates with home-manager’s native Claude Code support. MCP servers are managed through Nix and stored in the Nix store:

{
  imports = [ inputs.mcps.homeManagerModules.claude ];

  programs.claude-code = {
    enable = true;
    mcps = {
      git.enable = true;
      filesystem = {
        enable = true;
        allowedPaths = [ "${config.home.homeDirectory}/Projects" ];
      };
      asana = {
        enable = true;
        tokenFilepath = "/var/run/agenix/asana.token";
      };
    };
  };
}

Option 2: Script-based Installation

Uses the Claude CLI to manage MCP servers in ~/.claude.json. This approach is useful if you:

• Want your MCP server configurations to persist in ~/.claude.json
• Need to manually manage or edit MCP servers outside of Nix
• Prefer keeping custom MCP configurations in your home directory

{
  imports = [ inputs.mcps.homeManagerModules.claude-install ];

  programs.claude-code = {
    enable = true;
    mcps = {
      git.enable = true;
      buildkite = {
        enable = true;
        apiKeyFilepath = "/path/to/buildkite-token";
      };
    };
  };
}

Available MCP Servers

Built-in Presets

Module Structure

The project now provides focused modules that integrate with native Claude Code support:

• devenvModules.claude: Adds claude.code.mcps configuration to devenv’s native claude.code module
• homeManagerModules.claude: Adds programs.claude-code.mcps configuration to home-manager’s native Claude module
• homeManagerModules.claude-install: Alternative home-manager module that uses Claude CLI to manage ~/.claude.json

All modules provide access to the same preset MCP server configurations, allowing you to easily enable popular MCP servers with simple boolean flags.

Security Features

• Credential File Support: All MCP servers support reading credentials from files instead of environment variables
• Path Restrictions: Filesystem access is restricted to explicitly allowed paths
• No Credential Exposure: API tokens and keys are never exposed in the Nix store

Contributing

See CONTRIBUTE.md for development setup, testing, and contribution guidelines.

License

This project is licensed under the MIT License.