WebCodex gives ChatGPT, Claude, and other MCP clients a real development environment on machines you own, so an AI assistant can edit your actual repositories instead of a pasted snapshot. A self-hosted Server authenticates every request and routes it to a Runner sitting next to your code, where file edits, Git operations, test runs, shell commands, and long jobs execute with your real toolchain. Your projects never move into a hosted workspace; only the tool results you authorize travel back to the model. The browser Runtime Console shows project readiness, the work queue, session activity, and connected Runners, and it is where you decide pending approvals or accept and reject finished work, because the model cannot approve its own changes. Runners join with a short-lived pairing code and stay connected over QUIC, WebSocket, or polling, so machines behind NAT still work. One-command sharing opens a temporary session for a single repository, while durable setups run the Server and Runner as system services behind your own HTTPS domain. Workflow Sessions keep evidence and context across conversations, so long tasks survive closed browser tabs and threads you pick up days later. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.