Standards
JSON-LD
Also known as: JSON for Linking Data
A W3C-standardized JSON serialization for Linked Data. Every W3C Verifiable Credential is a JSON-LD document.
JSON-LD (JSON for Linking Data) is a W3C Recommendation for expressing RDF graphs in JSON. The magic is the @context: a map that tells parsers how to interpret JSON keys as IRIs, how to type values, and how to namespace across multiple vocabularies. Two JSON-LD documents with different shapes can express the same underlying graph if their contexts agree.
JSON-LD is the wire format for W3C Verifiable Credentials. Every LearnCoin credential is a JSON-LD document whose @context array declares, in order: the VC 2.0 context, the Blockcerts v3 context, and the Open Badges 3.0 context. The ordering matters because each subsequent context can refine or extend the terms the previous ones defined.
The alternative the VC Working Group considered — VC-JWT — encodes claims as a signed JWT payload. That's simpler to implement but loses the Linked Data graph model, so we stayed with JSON-LD.