Give Claude or Cursor a cloud sandbox, a database and a publish button over MCP

Coding agents in Claude, Cursor and Codex are good at writing code. They're weaker at everything around it: a machine to run the app on, a live preview, a database, file storage, secrets and a public URL at the end. Usually you wire that up yourself. This post shows how to hand all of that to the agent through one remote MCP server. I build Mythex, an AI app builder from Dubai, and this is how its MCP server works. The pattern applies to any MCP server that exposes a sandbox. What the agent gets Once connected, the client can: create or open a project and wake a cloud sandbox read, write, edit and search files, and run bash start a preview and read its logs (set_run_config, start_preview, get_preview) set secrets you provide (keys are listed back, values never are) add a Postgres database and file storage, make checkpoints, and publish run a Playwright browser script and get screenshots back in chat export or import code, sync with GitHub and connect a domain Every to