The present study analyzes contract procedures and their limits as of the liberal theory of fundamental rights. Using the indirect documentation technique by means of bibliographic research, it initially presents the origin and historic evolution of contract procedures abroad and in our legal order. Concepts and classifications of contract procedures under the optics of several authors are also presented. It evaluates hypotheses on contract procedures started as from articles 190, 191 and 357, § 2nd and § 3rd of the Code of Civil Procedure of 2015 (CPC/2015), as a way to bring up the main criticism made by the doctrine to this day, rather than discuss the theme thoroughly. It falls back on the judicial fact theory in order to analyze the procedural requirements, validity, and effectiveness of contract procedures, seeking to comprehend the criteria used by the doctrine to delineate the limits for the celebration of contract procedures. Lastly, by the use of elements from the German Legal Dogmatics, we identify: an area of protection of fundamental rights (freedom by the parts in the process); a state intervention in this area of protection (the Normative Instruction no. 39/2016 of the Labor Court, which, a few days prior to the CPC/2015 came into force, imposed that several legal devices of the new Code shall not be applied to Labor Processes, among which, art. 190 and Sole Paragraph, that is, the procedural negotiation), all of which intent on finding the constitutional justification for this intervention so that a conclusion is drawn as for the (in)constitutionality of state intervention.