When u don’t lie to ur homies

No cap usually refers to the phrase "no lie"

phrase that means no lie; truth; no limit. it is often used in a sentence with a dare or to express and emphasize a point.

Coming from twitch.tv Kappa meaning joking, no cap means no joke

Capping basically means that you are kidding or joking around so that would mean that “No cap” means that you aren’t.

Brief History: The term originates from the Twitch emote “kappa” which means that you are joking. Instead of when you aren’t kidding saying “No kappa”, it was shortened down to “No kap” and then interpreted by mainstream audiences as “No cap”.

A phrase that is akin to “it is true that” or “I think that”, “no cap” is often used to describe an opinionated statement or a statement that is believed to be true. Stemming from the verb capping (basically, “to lie”), it quite literally means “no lie.” Because of this, no cap can be used to describe something that is not thought to be true by the speaker’s audience. No cap can be used to describe factual statements, but due to its slang nature, it is most often used in an exclamatory manner.