Rail Connector MCP

Local MCP bridge for operating Claude Code Remote Control from Codex.

Same-OS contract: Codex, this MCP server, and Claude Code must run in the same operating-system context. Native Windows controls native Windows. A WSL installation controls Claude only when Codex and Claude both run inside that same WSL environment.

Rail Connector MCP combines Claude Code's local session logs and Remote Control CLI with a persistent Windows terminal broker or tmux on Linux and macOS. It lets Codex list, inspect, start, resume, continue, fork, prompt, wait for, capture, rename, archive, and stop local Claude Code conversations.

This project does not implement Anthropic's private cloud protocol. A local, authenticated Claude Code process remains required.

Rail Connector MCP is an independent open-source project. It is not affiliated with, sponsored by, or endorsed by Anthropic or OpenAI. Product names are used only to describe interoperability. See NOTICE.

Status

The current version is 1.0.0-beta.1, the first public beta candidate. Treat the MCP tool schemas and response fields as prerelease interfaces until a stable release is published. See Compatibility.

The package is intentionally marked private and is not published to the npm registry. Git tags and GitHub Releases are the public release authority.

Related MCP server: codex-mcp-server

Capabilities

• Local Claude conversation listing, search, inspection, resume, continue, and fork support

• Model, effort, Ultracode, permission, safe-mode, tool, and workspace-trust launch controls

• Persistent per-user ConPTY broker on Windows and validated tmux ownership on Linux/macOS

• Chunked prompt submission and transcript-backed completion waiting

• Session rename plus MCP-local archive metadata

• Requested, resolved, and observed launch-posture evidence

• Repo-scoped Codex operator, debugger, and reviewer skills

Requirements

• Windows, Linux, or macOS

• Node.js 22, 24, or 26

• npm and Git

• Claude Code CLI installed and authenticated

• Codex Desktop or Codex CLI with local MCP server support

• tmux 2.4 or newer on Linux/macOS

• Build prerequisites for node-pty when a matching prebuilt binary is not available; see Troubleshooting

Package installation scripts must be enabled because node-pty uses its install step to select a prebuild or compile. npm ci --ignore-scripts is unsupported.

Data And Trust Boundary

Rail Connector runs locally under the current user. It reads local Claude Code session logs and controls a local terminal process; MCP responses can include conversation text or Remote Control URLs when a caller requests those fields. The project has no telemetry service and does not upload session data. Claude Code itself still communicates with Anthropic under the user's Claude account.

Treat the Codex MCP client, the selected project directory, Claude hooks, and any enabled bypass policy as part of one local trust boundary. Use allowed roots when a registration should be limited to specific project trees.

Install

Install from the same OS environment that runs Codex and Claude Code.

For a published release, clone the immutable tag:

Linux:

git clone --branch v1.0.0-beta.1 --depth 1 https://github.com/SNComrade/Rail-Connector-MCP.git
cd Rail-Connector-MCP
./install.sh

macOS uses the same installer after the prerequisites in macOS Install are present.

Native Windows PowerShell:

git clone --branch v1.0.0-beta.1 --depth 1 https://github.com/SNComrade/Rail-Connector-MCP.git
cd Rail-Connector-MCP
.\install-windows.ps1

To evaluate unreleased work, clone main without --branch; do not describe a mutable main checkout as a released version. The source-tree installers are not included in the runtime-only npm tarball produced for release inspection.

The default installer runs syntax and smoke verification before registration. Pass --run-tests on Linux/macOS or -RunTests on Windows to run the complete suite during installation. CI always runs the complete suite.

The registered MCP server name is rail-connector; Codex tools appear under mcp__rail_connector after a fresh Codex task loads the registration. Bundled skills are repo-scoped. Use Codex's native $skill-installer for the three directories under .agents/skills/ when they should be available from unrelated project repositories; skill installation is an explicit, separate choice from MCP registration.

Permission Policy

Bypass mode is disabled by default. On an intentionally authorized development host, install with the explicit local-host policy:

./install.sh --bypass-policy LocalHost --allowed-root "$HOME/projects"

.\install-windows.ps1 -BypassPolicy LocalHost -AllowedRoot "$HOME\Projects"

Each bypass launch must still include confirmBypassPermissions: true. Bypass mode removes Claude's approval prompts and can modify any host resource available to the Claude process. Read Security Model before enabling it.

LocalHost is an advanced single-user development policy, not a claim that the host is isolated. Disabled remains the default. Restricting allowed roots is strongly recommended when LocalHost is enabled.

Verify

npm ci
npm test

Start with the MCP get_claude_capabilities and status tools. On Windows, status should report the persistent native broker backend. Use the actual task project as cwd, not this repository unless this repository is the review target.

Documentation

• Install Guide

• Windows Install

• Linux/WSL Install

• macOS Install

• Usage

• Security Model

• Task Guide

• Repo Skills

• Install Skills

• Troubleshooting

Project policies and maintainer references:

• Security Policy

• Support

• Contributing

• Code of Conduct

• Governance

• Compatibility

• Changelog

• Release Process

• GitHub Setup

• Agent Instructions

License

MIT. See LICENSE and Third-Party Notices.