Cross Domain · specification · OpenJS Foundation

JSON Schema

JSON Schema enables the confident and reliable use of the JSON data format, bringing consistency, validity, and interoperability to enterprise operations. JSON Schema defines the digital objects that we post to APIs, and receive as responses. JSON Schema defines the payloads of our APIs, but it also defines the surface area of our APIs as part of the OpenAPI specification. JSON Schema is ubiquitous in all enterprise organizations, bringing the following benefits to operations.

  • API Schema - Acts as a form of self-documentation for APIs, making it easier for developers to understand the expected data format and structure.
  • API Validation - Ensures incoming or outgoing JSON data conforms to a predefined structure, reducing errors and improving data integrity.
  • API Interoperability - Provides a standardized way to describe data formats, ensuring compatibility between systems using JSON for data exchange.
  • API Automation - Allows for code generation, form validation, and testing tools to work seamlessly by leveraging schema definitions.

JSON Schema provides these four basic building blocks that can be used to define and validate every aspect of enterprise API operations, helping teams be more precise and consistent when it comes to the requests made to APIs, as well as the responses that are returned.

  • Identifiers (URL reference to each schema)
  • Types (string, number, boolean, object, array, null)
  • Metadata (title, names, descriptions)
  • Constraints (minimum, maximum, required fields)
  • Properties (required and optional properties)
  • Patterns (regex-based validation for strings)
  • Structure (nested or references)

JSON Schema is a standardized and flexible way to validate, document, and enforce structure across your JSON data. It simplifies API design, enhances reliability, and reduces errors, making it a foundational specification for any API operation. APIs.json, OpenAPI, Spectral, and other commonly used API specifications all also use JSON Schema to validate the compliance with their specification, further baking it into API operations.

The inventory and refinement of JSON Schema and publishing them to Git repositories and/or publishing them to schema registries help encourage reuse and is the number one thing you can do to stabilize API operations. Ensuring that the latest version of the JSON Specification is in use across teams, with validators baked into build pipelines, and even API gateways in some cases, will all contribute to the stability and security of the API surface area of any enterprise.

json-schema.org/The standard
OpenJS FoundationGoverning body · Linux Foundation
2009First published
Draft 2020-12Current version
Yes — JSON SchemaMachine-readable schema · open
20providers in the catalog

Also known as JSON Schema Specification.

Providers that carry JSON Schema 20

These providers' own APIs.json profiles carry JSON Schema as a tag — the provider's statement that the standard is part of what it does. APIs.io has not verified the implementation on this page; the de facto profiles on this site are where that measurement exists. Ordered by Kin Score.

Reading

Read from the API Evangelist standards directory, facts verified 2026-08-17. Provider links come from the catalog's own identity tags and are rebuilt nightly. If this page is wrong about a standard or a provider, say so.