In 7-amino-5-tert-butyl-2-methyl­pyrazolo[1,5-a]pyrimidine, C11H16N4, which crystallizes with Z′ = 2 in the space group P\overline{1}, the independent mol­ecules are linked by four N—H⋯N hydrogen bonds into chains containing three types of ring. In 3,7-diamino-2,5-dimethyl­pyrazolo[1,5-a]pyrimidine monohydrate, C8H11N5·H2O, the mol­ecular components are linked into a three-dimensional framework structure by a combination of O—H⋯N, N—H⋯N and N—H⋯O hydrogen bonds.