Answer: Yes the contract is valid.
Explanation:
The United Nations Convention on Contracts for the International Sale of Goods (CISG) is a binding agreement between nations. It sets rules to govern commercial contracts between parties in different countries.
Article 11 of the CISG states that a contract of sale does not need to be in writing and may even be proved by witnesses to the contract.
In other words, agreements made in conversation are enforceable and as both France and Germany are parties to the CISG, the contract is valid.