Sigpy is an open-source python package for signomial and polynomial optimization. The project is maintained on github.
For signomials, sigpy implements the SAGE hierarchy as described by Chandrasekaran and Shah.
For polynomials, it uses the idea of a “signomial representative” to produce global lower bounds as described in my recent paper. The result is a theoretically and practically efficient method for computing lower bounds on polynomials, and is especially well-suited to sparse polynomials or polynomials of high degree. The bounds returned are always at least as strong as those computed by “SONC” and “SDSOS“, and can be stronger.