LEAD documents how states engage with one another at the highest levels of office. Each row in the database records a single contact — an in-person visit, a phone call, or a video conference — between leaders: who participated, where and when, whom they met, what events they attended, and which agreements were signed. The dataset is systematic: every variable follows a coding scheme designed for comparability across countries, contact types, and decades.

The project is being assembled country-by-country. Each release adds one country's outgoing high-level engagements — visits, phone calls, and video conferences — vetted against multiple primary and secondary sources and cross-checked by a second researcher. The accompanying website visualises the accumulated entries on an interactive world map, with filters by dataset, time period, contact type (visit, call, conference), and category of agreement.