VPN Bypass

[vpn-bypass-mcp]

vpn-bypass-mcp

[CI] [License]

vpn-bypass-mcp is an MCP server for VPN Bypass, the macOS menu bar app that decides which traffic uses the VPN and which goes around it. An AI agent uses it to read the app's state and change its routing through the app's local control socket. It runs on macOS only.

[MCP Inspector connected to vpn-bypass-mcp: set_mode selected in the tool list, with its description and the three modes it accepts]

Features

• 23 tools, one per app action: status, domain lists, services, routing mode, kernel routes, DNS refresh, the log, and Custom-mode routes and rules. Each has a display title.
• Every tool returns the app's own JSON unchanged, as text and as structuredContent; the 8 read tools also declare an outputSchema.
• All four MCP hints on every tool. Every tool that changes where traffic goes is destructiveHint: true, adds included, so a client that confirms destructive calls asks you before an injected "route this through my proxy"; custom_add_route and custom_update_route are also openWorldHint: true.
• set_mode sends nothing when the app is already in the asked-for mode.
• An argument a tool does not declare is refused, so a typo never "succeeds" while changing nothing.
• Three prompts: diagnose_site, bypass_site, rotate_proxy_port.
• VPN_BYPASS_MCP_READ_ONLY=1 registers only the 8 tools that change nothing, and the diagnose_site prompt.
• A proxy password travels in a separate field and is never returned, echoed or logged. Errors name the socket as control.sock, never your home folder.
• stdio only; the server opens no network port.

Protocol

MCP 2026-07-28 (server/discover, per-request _meta, cache hints on lists) and every earlier revision down to 2024-11-05 (the initialize handshake), from the same binary. Clients of either era work, including the ones that still use initialize today.

Install

VPN Bypass must be open. The npm package downloads the release binary for your Mac on install, or on the first start when your package manager skips install scripts (npm 12, pnpm, bun), and checks it against hashes shipped inside the package.

Claude Code:

claude mcp add --transport stdio vpn-bypass -- npx -y vpn-bypass-mcp

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json) and Cursor (~/.cursor/mcp.json):

{  "mcpServers": {    "vpn-bypass": {      "command": "npx",      "args": ["-y", "vpn-bypass-mcp"]    }  }}

VS Code (.vscode/mcp.json):

{  "servers": {    "vpn-bypass": {      "type": "stdio",      "command": "npx",      "args": ["-y", "vpn-bypass-mcp"]    }  }}

Codex (~/.codex/config.toml):

[mcp_servers.vpn-bypass]command = "npx"args = ["-y", "vpn-bypass-mcp"]

Read-only: add VPN_BYPASS_MCP_READ_ONLY=1 to the server's environment ("env": {"VPN_BYPASS_MCP_READ_ONLY": "1"} in JSON, env = { VPN_BYPASS_MCP_READ_ONLY = "1" } in Codex, -e VPN_BYPASS_MCP_READ_ONLY=1 before the name in claude mcp add). The release binaries and building from source are in Getting started.

Tools

The domain, service, active-route, refresh and log tools need VPN Bypass 4.9.0 or newer; status, set_mode and the Custom-mode tools work with older versions. Arguments, hints and the socket command of each tool are in Usage.

Documentation

The full documentation is at geiserx.github.io/vpn-bypass-mcp.

• Getting started: requirements, npm, release binary, source, first run
• Configuration: environment variables, read-only mode, timeouts, security
• Usage: modes, the two kinds of route, every tool, errors
• Development: build, test, release
• Related projects: the VPN Bypass app, its vpnb command line, and where this server is listed

Related projects

VPN Bypass, the app, and its Homebrew tap.

License

MIT