This web-based Toolkit compiling 12 essential tools and templates, developed and tested under the Gap Fund Step-Up Project (SUP), implemented by ICLEI with the City Climate Finance Gap Fund. Co-created with cities in Africa and South America, this Toolkit is designed to empower city officials, project managers and technical partners globally to: 1. Diagnose capacity and data gaps with needs assessment and governance tools 2. Map stakeholders, risks, and de-risking instruments for investment readiness 3. Build basic financial models and assess PPP applicability 4. Apply behavioural insights and systems thinking to project design 5. Identify a clear roadmap from pre-feasibility to bankability Each tool includes step-by-step guidance and downloadable templates that cities, city networks, practitioners, and trainers can adapt to their local context and use in trainings.