On 12nd of February 2020, Michael Paquier committed patch:
Add %x to default PROMPT1 and PROMPT2 in psql %d can be used to track if the current connection is in a transaction block or not, and adding it by default to the prompt has the advantage to not need a modification of .psqlrc, something not possible depending on the environment. This discussion has happened across various sources, and there was a strong consensus in favor of this change. Author: Vik Fearing Reviewed-by: Fabien Coelho Discussion: https://postgr.es/m/09502c40-cfe1-bb29-10f9-4b3fa7b2bbb2@2ndquadrant.com
Continue reading Waiting for PostgreSQL 13 – Add %x to default PROMPT1 and PROMPT2 in psql