The GCF aims to support developing countries in achieving a paradigm shift to low-emission and climate-resilient pathways. This is achieved by funding innovative and transformative lowemission (mitigation) and climate-resilient (adaptation) projects and programmes developed by the public and private sectors to contribute to the implementation of national climate change priorities in developing countries. While it is relatively easy to tell what a mitigation project or programme is (i.e. its contribution to the reduction of greenhouse gases in the atmosphere, and/or whether it increases the capacity of an ecosystem to absorb them), the blurred line between a general development project and an adaptation project has been a contentious issue in the international climate finance debate. The relevant question is not whether a project is (also) a development project, but whether the project contributes to adaptation (i.e. what the adaptation/additionality argument is). <br><b>This toolkit helps governments and project developers understand how to fulfil the Green Climate Fund’s requirements when developing a fully-fledged funding proposal.</b>