World, co-founded by OpenAI chief Sam Altman, has made ProveKit available to developers outside World ID, where it has been used since April. The toolkit enables users to prove claims such as age or nationality directly on their phones or browsers, with the verifier only receiving confirmation of the specific claim. ProveKit uses local proof generation, ensuring sensitive personal information remains on the user's device and is not sent to external servers. The company states ProveKit targets 128-bit post-quantum security and does not require a trusted setup.