JSONAPI

JSON API is a specification for building APIs in JSON. It defines how clients should request and modify resources, and how servers should respond, with the goal of minimizing both the number of requests and the amount of data transmitted. The specification is maintained by a community group and is versioned; the most widely adopted version is 1.1, published in 2022.

At its core, JSON API describes a standard structure for request and response bodies. Resources are represented as objects containing an “id”, a “type”, and an optional “attributes” member for resource data. Relationships between resources are expressed through a “relationships” member, which can include linkage data and related resource objects. Errors are returned in a consistent format providing a status code, title, detail, and optional source pointer.

The specification also defines HTTP query parameters for sorting, pagination, field selection, and filtering, allowing clients to tailor responses to their needs. Media types are standardized as application/vnd.api+json, which signals that the payload conforms to the JSON API format. Servers that follow the spec can automatically provide features such as sparse fieldsets and compound documents, reducing the need for custom client‑side parsing logic.

Numerous libraries implement JSON API across programming languages, including Ruby on Rails, JavaScript (Axios and Ember Data), Python (Flask‑JSONAPI), and Java (Spring Data REST). While the standard promotes consistency, critics note that its strict conventions can add complexity for simple APIs. Nonetheless, JSON API remains a prominent approach for designing scalable, interoperable web services.