This document describes changes from v7.2.4 to v8.0.0.

If you are migrating from v6 you can use this document.

New features

Support JSON Schema draft-2020-12: prefixItems keyword and changed semantics of items keyword, dynamic recursive references.
OpenAPI discriminator keyword.
Improved JSON Type Definition support:

• errors consistent with JTD specification.
• error objects with additional properties to simplify error handling (see Error objects)
• internationalized error messages with ajv-i18n
  TypeScript: support type unions in JSONSchemaType

Other changes / improvements

Node.js require works without .default property - see examples in Getting started
Reduce runtime dependency for standalone validation code
Fix resolution of $ref: "#" when $id is present (#815)

Breaking changes

Option strict controls all strict mode restrictions
JSON Schema validation errors changes:

• dataPath property replaced with instancePath
• "should" replaced with "must" in the messages
• property name is removed from "propertyName" keyword error message (it is still available in error.params.propertyName).