Algebraic solution of the Jacobi inverse problem and explicit addition laws

We formulate a solution to the Algebraic version of the Inverse Jacobi problem. Using this solution we produce explicit addition laws on any algebraic curve generalizing the law suggested by Leykin [2] in the case of (n, s) curves. This gives a positive answer to a question asked by T. Shaska whether addition laws appearing in [2] can be produced in a coordinate free manner.