We provide an open source toolbox on https://github.com/ct2641/CAI/releases/tag/1.0 to conduct computer-aided investigation on the fundamental limits of information systems. The toolbox relies on either Gurobi or Cplex as the linear program solving engine. The program can read a problem description file, and then fulfill the following tasks: 1) compute a bound for a given linear combination of information measures and provide the value of information measures at the optimal solution; 2) efficiently compute a polytope tradeoff outer bound between two information quantities; 3) produce a proof (as a weighted sum of known information inequalities; and 4) provide the range for information quantities between which the optimal value does not change (sensitivity analysis). This technical report provides an overview of this toolbox, a detailed description of the syntax of the problem description file, and a few example use cases.