This MASTER SALES AGREEMENT (this "Agreement") sets forth the terms and conditions. The information contained in this Standard.Document is specific to Texas and refers to the Uniform Commercial Code enacted under Texas law and not the model. Electronic versions of Texas Purchase Agreements. These purchase agreements were deigned specifically for use in the State of Texas. Representations of the City . The forms listed below are PDF files. They include graphics, fillable form fields, scripts and functionality that work best with the free Adobe Reader. A master purchase agreement is a legally binding contract between buyer and seller, and typically relates to buying and selling goods rather than services.