There is no clear contract, but there are facts. If there is an oral contract, it is also the way of contract.

The parties may conclude a contract in writing, orally or in other forms. If the parties agree to use written form, it shall be in written form.

According to the Contract Law of People's Republic of China (PRC)

Article 10 The parties may conclude a contract in writing, orally or in other forms.

If laws and administrative regulations stipulate that it should be in writing, it should be in writing. If the parties agree to use written form, it shall be in written form.

Article 11 Written forms refer to forms such as contracts, letters and data messages (including telegrams, telexes, faxes, electronic data interchange and e-mails) that can tangibly express the contents contained.