If that is what you meant, than you are getting in the realm of hypothesis testing. The best equivalent of a p-value is then an anabashedly named "Bayes factor"

If that is what you meant, than you are getting in the realm of hypothesis testing. The best equivalent of a p-value is then an anabashedly named "Bayes factor" [1], which is a ratio of posterior probabilities for competing hypotheses. https://en.wikipedia.org/wiki/Bayes_factor https://en.wikipedia.org/wiki/Bayes_factor