Hapi is a novel easy-to-use package that only requires 3 to 5 gametes to reconstruct accurate and high-resolution haplotypes of an individual. The gamete genotype data may be generated from various platforms including genotyping arrays and next generation sequencing even with low-coverage. Hapi simply takes genotype data of known hetSNPs in single gamete cells as input and report the high-resolution haplotypes as well as confidence level of each phased hetSNPs. The package also includes a module allowing downstream analyses and visualization of crossovers in the gametes.