Once GreasySpoon is installed, open your web browser on http://127.0.0.1:8088 (or GreasySpoon server IP address if not running locally), login with admin/admin login and password (default) then go to "GreasySpoon Scripts" page.
If you want to enrich HTTP requests (GET/POST) Messages, select "Request Scripts".
If you want to manipulate HTML responses, select "Response Scripts".
Then click on "new script" button to create a new service.
Choose a name for your service, select your favorite language and select "Apply". It opens the editor interface on which you can start developping your service.
You can directly start to code your service. Don't forget to save your modifications before leaving the page (either by clicking on "Save" or by using <Control><s> shortcut).
Scripts application is managed through a control header, explained in next chapter. A basic header skeletton is created with new scripts, and should be adapted based on your needs (see next chapter for details).
Once the script status has been turned to "on" (either by setting the @status tag or by enabling the script on the interface), modifications made on your code are applied in real time, when saving your code.