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mcp-bash-server

The problem

Cowork and Claude Desktop run in a sandbox and can't execute commands on your own machine. mcp-bash-server bridges that gap: it connects Cowork to your local bash so Claude can run shell commands directly on your computer and read their output.

Install (no terminal)

Download mcp-bash-server.mcpb from the latest release and double-click it. Claude Desktop installs it — no pip, no config files. It uses the uv runtime, so Python isn't required. Once installed, it also shows up inside Cowork.

The tool

run_bash(command, cwd?, timeout?) — runs a command via bash -c and returns exit code, stdout, and stderr.

Configuration

• BASH_MCP_ALLOWED — comma-separated allowlist of command prefixes (blank = full shell)
• BASH_MCP_CWD — default working directory
• BASH_MCP_MAX_TIMEOUT — hard cap on command runtime (seconds)

Security

With no allowlist set, this is an open shell — the client can run anything you can. Set BASH_MCP_ALLOWED if you share it.

See the README for full details.