# 20000419/fauxnix [Health: Active]

**Category:** 🖥️ Command Line  
**Repository:** https://github.com/20000419/fauxnix  
**GitHub Stars:** 903  
**Views:** 1  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/20000419-fauxnix

## Description
bash for AI agents on Windows via deterministic bash→PowerShell translation — no WSL, VM, or bash toolchain. MCP bash tool with GNU-style output, bash-style errors, coreutils exit codes, session-persisted cwd/env across calls, and per-file UTF-8/GBK sniffing (GBK files grep correctly, unlike Git Bash). Unsupported bash constructs fail loudly with the construct named; native commands (git/node/npm) pass through with argv quoting. npm install -g fauxnix-cli; verified with Claude Code, Codex, OpenCode, Kimi Code and Qwen Code.

## Claude Desktop Quick Installation
No confirmed install details yet, so no config is published. Follow the setup steps in the repository above.

## Documentation

## What 20000419/fauxnix does

20000419/fauxnix provides a Windows-native command layer for AI agents that write bash. Instead of requiring a Bash runtime, it converts supported bash syntax and commands into PowerShell operations, executes them on the local Windows filesystem, and formats results to resemble GNU/Linux command-line behavior.

The package covers a broad subset of file management, text processing, process management, archives, and basic networking commands. Examples include `ls`, `find`, `grep`, `wc`, `cp`, `mv`, `rm`, `chmod`, `stat`, and `kill`. Commands that are outside the supported translation subset fail explicitly and identify the unsupported construct rather than producing a silent or approximate result. Native programs such as `git`, `node`, and `npm` pass through with argument quoting adapted for Windows.

## How it works

The MCP entry point is started with `fauxnix mcp` over stdio. Its primary tool is named `bash`; the name can be changed with `FAUXNIX_TOOL_NAME`. Each call runs in a persistent session. Changes to `cwd`, exported or unset variables, `OLDPWD`, and positional parameters remain available to later calls, so the interaction resembles a logged-in shell rather than independent process launches.

For predetermined workflows, `bash_batch` accepts an ordered list of command steps. fauxnix compiles the complete plan before execution, runs it in one session, and returns a structured result for each step. Execution stops at the first nonzero exit by default.

Input and output handling includes UTF-8 and GBK file detection, GNU-like listings, bash-style error text, and coreutils-compatible exit codes. The implementation makes no runtime LLM calls.

## Setup and configuration

Install the CLI globally with:

```bash
npm install -g fauxnix-cli
```

The runtime requires Windows, PowerShell 5.1 or newer, and Node.js 22.20.0 or newer. Start the MCP server with:

```bash
fauxnix mcp
```

The installer can add configurations for supported harnesses:

```bash
fauxnix install --claude
fauxnix install --codex
fauxnix install --opencode
fauxnix install --kimi
fauxnix install --qwen
```

Run `fauxnix doctor` to check encoding support, harness configuration, and an MCP round trip. Manual configuration uses the command `fauxnix` with the argument `mcp`.

## Tools and capabilities

- Translate supported bash commands into native PowerShell execution.
- Preserve working directory, environment, exports, `unset`, `cd -`, and positional parameters between calls.
- Provide GNU-style output and bash-like errors on Windows.
- Detect UTF-8 and GBK files per file for text operations such as `grep`.
- Execute multi-step `bash_batch` plans with one MCP round trip.
- Pass native Windows commands through with argv quoting.
- Run directly from the CLI, including `fauxnix "ls -la src"` and `fauxnix translate "..."`.

## Limitations and notes

fauxnix translates a defined command and syntax subset rather than implementing a complete Bash shell. Unsupported constructs fail loudly, so workflows depending on arbitrary Bash features should be tested against the translator. Node.js 18 and 20 are unsupported for the v2 release.

The server uses a local stdio connection and executes commands on the Windows host. In Codex non-interactive `codex exec` mode, MCP calls are automatically denied by the approval layer unless approvals and sandbox restrictions are bypassed as described by the project configuration. The optional Claude Code native shell facade is experimental and separate from the MCP server.

_Full upstream README: https://allmcps.com/mcp/20000419-fauxnix/readme_