This Lab Report is an interim deliverable of the ongoing Independent Evaluation of the GCF’s Readiness and Preparatory Support Programme (RPSP) 2024–2027. It presents synthesized learnings from the evaluation interviews and focus group discussions, literature review, and data collection and analysis done so far during the inception- and early data collection and analysis phases. As an interim deliverable, this lab report does not contain the final conclusions and recommendations of the evaluation. The Lab Report briefly covers the evolution of GCF’s readiness support through the three key RPSP strategy phases (the initial RPSP phase of 2014–2018; RPSP Strategy 2019–2021 period which was extended to the end of 2023; and the RPSP Strategy 2024–2027 which is currently in effect at the time of this evaluation), and highlights the available evidence and lessons around the current Strategy 2024–2027 (or Readiness 3.0) period and the Strategy operations so far.