tarsius/edit-server — comment on commit 3da88a5524fe191e9ba346d54d174512c53a67c1
File:  line 0
By stsquad:

The mechanism between the client and server does allow for iterative editing so the C-x C-s key-stroke should be able to send the current state of the buffer to the browser. However this doesn't solve the problem you were having as the browser can still be closed in-between saves. Instead of merging your patch I've put forward a slightly different one which calls a specific function for C-x C-s - namely edit-server-save. Currently this just yanks the buffer into the kill-ring.