An agreement via text message may or may not be binding under the law. For example, agreements for transfer of real estate must be in writing, signed by the person selling the real estate. And there are many other examples of agreements that must be in writing and signed. However, a text agreement may very well be binding if the law does not specifically require the contactual agreement to be in writing and signed. An attorney can properly advise you, based on the specific facts of your situation.