json_schema_ast

Build, validate, and resolve Draft 2020-12 JSON Schema and OpenAPI 3.1 Schema Object documents.

Installation

Add to your Cargo.toml:

[dependencies]
json_schema_ast = "0.3.1"

Usage

use json_schema_ast::{SchemaDocument, compile};
use serde_json::json;

let raw = json!({
    "type": "object",
    "properties": {
        "id": { "type": "integer" },
        "name": { "type": "string" }
    },
    "required": ["id"]
});

let schema = SchemaDocument::from_json(&raw).unwrap();

assert!(schema.is_valid(&json!({ "id": 42 })).unwrap());
assert!(!schema.is_valid(&json!({ "name": "Ada" })).unwrap());

let validator = compile(&raw).unwrap();
assert!(validator.is_valid(&json!({ "id": 42 })));

API

Most callers only need:

• SchemaDocument::from_json(&Value) builds a document from a raw Draft 2020-12 JSON Schema or OpenAPI 3.1 Schema Object.
• SchemaDocument::is_valid(&Value) validates instances against the original raw schema.
• compile(&Value) returns a ready-to-use validator after this crate's dialect checks.

Lower-level APIs for canonicalized schema access, resolved graph traversal, and typed errors are documented on docs.rs. developing.md explains how this repository uses them internally.

If a schema document sets $schema, it must be either Draft 2020-12 (https://json-schema.org/draft/2020-12/schema, with an optional trailing #) or the OpenAPI 3.1 Schema Object dialect (https://spec.openapis.org/oas/3.1/dialect/base). Omitting $schema is allowed and is interpreted as Draft 2020-12. OpenAPI 3.0-only schema semantics such as nullable are not interpreted; use the OpenAPI 3.1 / JSON Schema form instead.

Same-document refs to "#" and "#/..." are supported, including recursive graphs. Pure alias cycles, remote refs, plain-name fragments, and dynamic refs are rejected with typed resolver errors.

More detail

• Developer guide for resolved-IR internals and constraint design
• Repository README for the broader jsoncompat workflow
• docs.rs for API reference

License

Licensed under MIT. See LICENSE.