Today I’ve created a CodePlex project for a Todoist C# Class Library I’ve built.
Please check it out at http://todoistapi.codeplex.com
The reason for building this has primarily been to enable to convert my Todoist items to iCal and have them displayed in my google calendar. You can also use this service through my new labs site. Have a look at http://labs.deap.nu/Labs/TodoistIcal/TodoistIcal.aspx
Anyway, thats probably why the API currently only contains functionality for reading data. But the Todoist API at todoist.com certainly exposes methods to make it possible to add items, projects etc. If you are planning to do any kind of Todoist integration from a .net application, please contribute to this class library to make it mirror the Todoist API completely. You can request to join the project at codeplex and check out the source code with Tortoise SVN.
If you’ve never heard of Todoist, check out todoist.com, it’s a really great tool for keeping track of stuff to do :-).