OATS for Rust

use oatschema::{SchemaName, schema_json};let text = schema_json(SchemaName::Classification, None)?; // the file, exactly as releasedassert!(text.contains(r#""$id": "https://oatschema.org/0.8.0/classification""#));assert_eq!(oatschema::SCHEMA_VERSION, "0.8.0"); // used when you don't pass a versionlet name: SchemaName = "llm-output".parse()?; // or SchemaName::LlmOutputlet pinned = schema_json(name, Some("0.8.0"))?;

Schema names are a SchemaName enum, so typos fail at compile time. Each schema is byte-identical to its release on this site, and the crate's tests check every file against a checksum manifest.

The crate has no validator of its own; pass a schema to any JSON Schema draft 2020-12 validator. With the jsonschema crate and the serde_json feature:

cargo add oatschema --features serde_jsoncargo add jsonschema serde_json

use oatschema::SchemaName;use serde_json::json;fn main() -> Result<(), Box<dyn std::error::Error>> {    let schema = oatschema::schema(SchemaName::Classification, None)?;    let validator = jsonschema::options().should_validate_formats(true).build(&schema)?;    assert!(validator.is_valid(&json!({"labels": [{"label": "cat", "score": 0.92}]})));    for error in validator.iter_errors(&json!({"labels": [{"label": "cat", "score": 1.5}]})) {        println!("{}: {error}", error.instance_path()); // /labels/0/score: 1.5 is greater than the maximum of 1    }    Ok(())}

Build each validator once and reuse it. Turn on format checking (uri, date-time and so on), as above, to match the OATS packages for other languages. x-license and x-version are the only non-standard keywords, and draft 2020-12 validators treat them as annotations.

Before OATS 1.0, a new release may reject records an older one accepted, so pass the version a record was written for: schema_json(name, Some("0.8.0")).

• version is an Option<&str>; None means SCHEMA_VERSION. It must be exact: "0.8.0", never "0.8" or "latest".
• Each $id includes its version, so several versions can share one validator registry.
• The crate bundles OATS 0.8.0, the first public release, and every later one. For 0.4.0 to 0.7.0, use the Python package, or fetch them from this site.

More on releases in Versions and URLs.

The crate has its own semantic version, which never encodes a schema version. Upgrading never removes a schema version. Before 1.0, a release that bundles a new OATS release, and so changes the default SCHEMA_VERSION, is a minor bump, so Cargo's default 0.x.y requirement keeps your default fixed. Raising the minimum supported Rust version is also a minor bump.