This document describes a pilot project called the Digital Democracy and Common Data Commons (DDDC) pilot that will take place in Barcelona from October 2018 to April 2019. The pilot will use DECODE and Decidim technology to enable citizens to make policy proposals and collectively govern data commons. It will involve a series of engagement events focused on governance, legal and economic issues relating to data and digital democracy. The goal is to experiment with technologies that empower citizens to transparently and privately propose, debate, and decide on data issues.