Contracts take effect only between the parties, their assigns and heirs, except in case where the rights and obligations arising from the contract are not transmissible by their nature, or by stipulation or by provision of law. The heir is not liable beyond the value of the property he received from the decedent.
If a contract should contain some stipulation in favor of a third person, he may demand its fulfillment provided he communicated his acceptance to the obligor before its revocation. A mere incidental benefit or interest of a person is not sufficient. The contracting parties must have clearly and deliberately conferred a favor upon a third person. (1257a)