ConstraintProgrammingExtensions.jl is a project bringing constraint programming to JuMP. Its main part is a large series of constraints that aim at providing a common interface for constraint-programming solvers. It also consists of a series of bridges that define relationships between those sets (including between high-level constraints such as knapsacks and mathematical-programming formulations) and of a FlatZinc reader-writer to import and export models in that common format.