Coda is a comprehensive Web Editor and IDE.

It has limited support for exchanging files with other iOS applications on iOS yet unprecedented support for working with files on remote servers.

Working Copy can act as a WebDAV server letting Coda edit files directly in your Git repositories with no need to copy files back and forth.

You need to enable the WebDAV server in Working Copy and create a WebDAV server inside Coda representing Working Copy. Because both ends of the networking connection are on your device, this will work even when you have no Internet connection.

Working Copy is only allowed to run in the background for a limited amount of time and when the app is no longer running the WebDAV server is stopped.

On iPad you can keep both apps in the foreground at the same time using Split-View to keep WebDAV running.

Otherwise you can install a shortcut to make it faster to restart WebDAV. This is available from the App Integration page for the Shortcuts app.