Etymology of 'cap' [Tik-Tok slang]

Before several minutes ago, I’d never heard ‘cap’ as Tik-Tok slang for ‘lie’. What is the etymology? Is it an acronym?

This seems plausible:

So, where did “No Cap” come from?

The phrase was popularized by Atlanta-based rappers Young Thug and Future, who released their track “No Cap” back in 2017. But they weren’t using the phrase as totally a euphemism for “lie.” They implied it’s actual meaning with the word, as in there was no ceiling on the amount of jewelry, cars, and excesses they could afford and enjoy on a daily basis as a result of their immense talent and work ethic.

Which is kind of admirable in a way, to see these dudes pep talking themselves into going after their dreams.

So, how did “no cap” essentially become another way of someone stating, “no lie”? Perhaps the dedication to expressing just how serious they were about attaining said dreams became conflated with the same seriousness of averring what one is saying is the truth.
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