OpenRefine http://openrefine.org/ allows URL generation using GREL as tokens. I want to connect to an API which only supports a POST method . Can I format the URL so it calls the REST API using POST? Ref: https://github.com/OpenRefine/OpenRefine/wiki/Fetching-URLs-From-Web-Services
Not currently, but it'd be a good enhancement request. Click "issues" at the OpenRefine site URL that you posted.
Bonus points for patches/pull requests which implement the feature. :-)