An ELIXIR Common Data Management Toolkit is intended to support researchers and data stewards to enable lifecycle management for their research data, according to international standards, and integrated in the national context. The goal is to support FAIR by Design: from the first steps of producing FAIR data and Data Management Planning to the final steps of depositing data in public archives through data brokerage pathways from data management systems (Task 1.2) and enabling its reuse. The vision of the Toolkit has matured into three, interlinked, streams: 1. The RDMKit, a website-based toolkit designed to guide life scientists and data stewards in their efforts to better manage their research data. 2. Tool Assemblies, which are examples of combining tools to cover stages of the RDM Lifecycle and assembly patterns to report how tools can be combined and replaced by local specialisations. 3. Data Stewardship Wizard, which leads data stewards through decision trees to choose the right tools, resources and practices when planning their data management. WP3 has concentrated on the RDMKit. This provides rapid and maximum benefit to the Node’s Life Science communities and effectively coordinates and integrates the work of the CONVERGE WPs around a common goal. It also provides a timely resource for funders such as the EC’s Open Science Unit during development of the HorizonEurope programme. The RDMKit is targeted at researchers, data managers and data stewards in laboratories, facilities or universities; project consortium coordinators and funding agencies and policy makers. The RDMKit’s underlying technical infrastructure has been established using GitHub (https://github.com/elixir-europe/rdmkit) and the contribution and editorial processes put in place. Content has been assembled through hackathons/contentathons. This deliverable reports on the conception, design, implementation of the RDMKit, its open contribution, review and editorial processes, gives screenshot examples and lays out the next steps. The RDMKit is available at https://rdm.elixir-europe.org/ and https://rdmkit.elixir-europe.org/ (aliases) and will be internally beta released for review and awareness raising on 31 January 2021 and publicly released on 31 March 2021.