Is the Book of Bukhari considered among the Books of God?

Belief in the Books of Allah means believing in the books that He revealed to His messengers, as Allah Almighty says: "The Messenger has believed in what was revealed to him from his Lord, and [so have] the believers. All of them have believed in Allah and His angels and His books and His messengers." This does not include Sahih al-Bukhari, nor is it obligatory to believe its hadiths from this perspective.