When it comes to reaching a consensus, there are several synonyms for the phrase "agreement of all" that can be used interchangeably. One option is "unanimity," which refers to a complete and total agreement among all parties involved. Another synonym is "harmony," which suggests a positive and cooperative agreement between individuals or groups. "Consensus" is another synonym that denotes a general agreement or unity of opinion. In addition to these synonyms, other options include "conciliation," "concurrence," and "accord," each of which suggest a general agreement among all involved parties. Ultimately, the use of any of these synonyms can help convey the idea that all individuals or groups involved have come to a mutual understanding and agreement.