Configuration¶

mcpplay works with zero configuration. Everything is set via CLI flags.

mcpplay run server.py --port 9000 --no-reload --verbose

See the CLI Reference for all options.

Environment variables¶

Pass env vars to the MCP server with --env:

mcpplay run server.py --env API_KEY=sk-xxx --env DATABASE_URL=postgres://localhost/mydb

These are merged on top of your shell environment.

Data storage¶

Timeline data is stored in a SQLite database. Default paths:

Platform	Path
macOS	`~/Library/Application Support/mcpplay/timeline.db`
Linux	`$XDG_STATE_HOME/mcpplay/timeline.db` or `~/.local/state/mcpplay/timeline.db`
Windows	`%LOCALAPPDATA%\mcpplay\timeline.db`

Override with --data-dir:

mcpplay run server.py --data-dir /tmp/mcpplay-data

Security¶

mcpplay binds to 127.0.0.1 only - it is not accessible from other machines. A security middleware validates Host and Origin headers on every request to prevent cross-site attacks against your local instance.

Warning

mcpplay is a development tool. Don't expose it to the public internet via port forwarding or tunnels. Only run MCP servers you trust.