Independent This document defines CBOR::Core, a platform-agnostic profile for CBOR (RFC 8949) intended to serve as a viable replacement for JSON in computationally advanced systems like Internet browsers, mobile phones, and Web servers. For enhanced strictness, as well as for enabling cryptographic methods like signing and hashing, to optionally be applied to "raw" (non-wrapped) CBOR data, deterministic encoding is mandated. Furthermore, the document outlines API features for manipulating CBOR data in a secure manner. This document mainly targets CBOR tool developers.