It literally takes a 2 second Google search of just the two terms Palantir and anthropic to find sources for this and is fairly well known.

https://investors.palantir.com/news-details/2024/Anthropic-a...

https://www.cnbc.com/2026/03/12/karp-palantir-anthropic-clau...

https://www.reuters.com/technology/palantir-faces-challenge-...

Any company of Palantir size is not just gonna have people using personal subscriptions to use Claude on mission critical software or it's development.