Firefox extension providing an HTTP-based API. Users are able to install endpoint scripts (pretty much alike userscripts for Greasemonkey / Tampermonkey), which can be called by sending an HTTP request to localhost. The requests contain a target URL and (optionally) some additional parameters. Goaticmonkey opens the target URL and executes the script defined in the endpoint's code.
Please note, only install endpoint scripts from trusted sources : ignoring to do so may open the browser to vulnerabilities.
You can build the extension from the goaticmonkey/ directory using jpm xpi
Sample endpoints for Goaticmonkey.