Article 1216 of the French Civil Code
A contracting party, the assignor, may assign his status as a party to the contract to a third party, the assignee, with the agreement of his co-contracting party, the assignee. This agreement may be given in advance, in particular in the contract concluded between the future assignor and assignee, in which case the assignment takes effect with regard to the assignee when the contract concluded between the assignor and assignee…