This SGA provides comprehensive programming and support for the European Commission’s Mission of 100 Climate-neutral and Smart Cities by 2030. It builds on the NetZeroCities (NZC) project, coordinated by CKIC. Combined, these two projects set out actions as follows: (a) Create and operate a Cities Mission Platform as a ‘one-stop-shop’ to access the expertise, capabilities, services, and solutions necessary to achieve climate neutrality. This Platform will provide tailored and intensive support to cities participating in the Mission and will ensure open access to the knowledge and resources of the Platform. (b) Help all Mission Cities with the co-creation and use of Climate City Contracts (CCC) to enable an ambitious pursuit of the goal of climate neutrality by 2030. This SGA expressly seeks to ensure all Mission Cities are supported and builds directly on the initial scope of NZC. In addition, support will be offered to additional cities seeking to follow the Mission closely. (c) Assist Mission cities in the development of tailor-made investment plans, project preparation and finance for the cities participating in the Mission. (d) Deliver substantial resources to Mission cities for ongoing research and innovation activities critical to achieving climate neutrality by 2030. This support will be in the form of ‘pilot’ funding to test and demonstrate actions needed to deliver climate neutral outcomes. This pilot activity will work together with the Platform and CCC processes in the cities, operationalising emerging knowledge and insights about how cities can achieve the Mission objectives.