JSON Data Interchange Format
JSON is the lingua franca of web APIs. RFC 8259 is short and worth reading once — it clarifies edge cases around numbers, encoding, and trailing commas.
What It Defines
Defines the JSON syntax: objects, arrays, strings, numbers, booleans, null. The dominant serialization format for APIs, configuration, and data interchange.
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
JWTs are the token format for OIDC ID tokens and many OAuth implementations. Understanding the structure and security tradeoffs is essential.
When your app verifies a JWT from an identity provider, it fetches the public key as a JWK from the OIDC discovery endpoint.
JSON Schema is the standard way to document and validate API request/response shapes. OpenAPI 3.1 fully adopts it. Know it if you design APIs.