nu

nu-mcp exposes Nushell as an MCP server using the official Rust SDK (rmcp). It runs a core command execution surface (run) and can be extended with a catalog of Nushell-based tools located under the tools/ directory. By default you can start nu-mcp to enable the core run capability, and you can enable an extension toolset by pointing to a custom tools directory with --tools-dir. The server supports a global timeout via MCP_NU_MCP_TIMEOUT and allows per-call timeout settings through the timeout_seconds parameter in tool invocations. This makes it suitable for integrating Nushell commands into automated pipelines or chat-based tooling, while maintaining security through a sandbox and path validation. The included tool catalog covers Kubernetes, ArgoCD, Tmux, and Context7, among others, and tools can be used to perform common admin and scripting tasks through MCP-compatible commands.

Prerequisites:

• Nushell installed and available on the PATH
• A compatible runtime environment (Nix, Homebrew, or manual binary release) per the platform you’re using
• Optional: Rust toolchain if you’re building or tweaking the server from source

Install options (choose one):

1. Via Nix (recommended for Nix users)

• Install the MCP server (standalone): nix profile install github:ck3mp3r/nu-mcp

• Or install the complete tool collection: nix profile install github:ck3mp3r/nu-mcp#mcp-tools

• To use the server with tools, install the tool collection and start nu-mcp: nu-mcp --tools-dir=./tools

• To install as an overlay in a flake, follow the example in the README: Add inputs.nu-mcp.url = "github:ck3mp3r/nu-mcp" and expose pkgs.nu-mcp in your outputs.

2. Via Homebrew (macOS and Linux)

• Tap the repository and install: brew tap ck3mp3r/nu-mcp https://github.com/ck3mp3r/nu-mcp brew install nu-mcp

3. Quick start (local run without tooling changes)

• Start the server with the default core mode (run tool available): nu-mcp

Prerequisites notes:

• Ensure Nushell is installed and accessible in your PATH.
• The nu-mcp server can be configured to load tools from a local directory via --tools-dir; ensure the directory exists and contains tool modules with mod.nu entry files as described in the docs.

Tips and notes:

• Timeout and sandbox: You can set a default timeout using the MCP_NU_MCP_TIMEOUT environment variable. Individual tools may also accept timeout_seconds for per-call control. The sandbox includes path validation and caching to prevent unauthorized file system access while allowing legitimate API/output strings (e.g., API endpoints) to pass through.
• Tools: The tools/ directory houses modular Nushell scripts. Each tool directory should contain a mod.nu entry file. You can enable extension tools with --tools-dir=PATH and combine core execution with tools using --enable-run-nu.
• Destructive operations: Several tools include destructive capabilities and require explicit user confirmation. See the README’s safety and destructive operations sections for details and warnings that are propagated to LLMs and automation.
• Path access: Use --add-path to grant access to additional directories. The current working directory is always accessible by default.
• Security: Commands run within a configurable sandbox with two-tier validation to balance security and flexibility. Refer to docs/security.md and docs/configuration.md for in-depth guidance.