I wrote a web-based MMO with the goal that players would augment their experience by enhancing their client (potentially allowing a single player to control 10s of units RTS-style) as well as writing AI/bots to help them. The game can be played entirely by bots (this is how I tested it during development). Interestingly, the game balance and mechanics are such that a skilled solo hero can take on large numbers of bots and win (see this gameplay GIF: https://github.com/srpeck/kchess/blob/gh-pages/docs/kchess.g...).

The major enabling feature is that I do not differentiate between players and AI - both are networked clients (see here for the API docs: https://github.com/srpeck/kchess/blob/gh-pages/docs/kchessdo...). I wrote up some of my other design decisions here: https://news.ycombinator.com/item?id=10924316

And sorry, the live demo is currently down...but should be pretty quick/easy to run your own locally.