# jsonschema
[
](https://crates.io/crates/jsonschema)
[
](https://docs.rs/jsonschema)
[
](https://github.com/Stranger6667/jsonschema/actions?query=branch%3Amaster)
[
](https://app.codecov.io/github/Stranger6667/jsonschema)
[
](https://bowtie.report/#/implementations/rust-jsonschema)
A high-performance JSON Schema validator for Rust.
```rust
use serde_json::json;
fn main() -> Result<(), Box> {
let schema = json!({"maxLength": 5});
let instance = json!("foo");
// One-off validation
assert!(jsonschema::is_valid(&schema, &instance));
assert!(jsonschema::validate(&schema, &instance).is_ok());
// Build & reuse (faster)
let validator = jsonschema::validator_for(&schema)?;
// Fail on first error
assert!(validator.validate(&instance).is_ok());
// Iterate over errors
for error in validator.iter_errors(&instance) {
eprintln!("Error: {error}");
eprintln!("Location: {}", error.instance_path());
}
// Boolean result
assert!(validator.is_valid(&instance));
// Structured output (JSON Schema Output v1)
let evaluation = validator.evaluate(&instance);
for annotation in evaluation.iter_annotations() {
eprintln!(
"Annotation at {}: {:?}",
annotation.schema_location,
annotation.annotations.value()
);
}
// Generated validators are significantly faster than runtime ones,
// so prefer them when the schema is known at build time.
// Requires the `macros` feature.
// Inline schema, or `path = "schema.json"` to load from a file
#[jsonschema::validator(schema = r#"{"maxLength": 5}"#)]
struct Short;
assert!(Short::is_valid(&instance));
Short::validate(&instance)?;
Ok(())
}
```
You also can use it from the command line via the [jsonschema-cli](https://github.com/Stranger6667/jsonschema/tree/master/crates/jsonschema-cli) crate.
```console
$ jsonschema-cli validate schema.json -i instance.json
```
See more usage examples in the [documentation](https://docs.rs/jsonschema).
> ⚠️ **Upgrading from older versions?** Check our [Migration Guide](https://github.com/Stranger6667/jsonschema/blob/master/MIGRATION.md) for key changes.
## Playground
If you'd like to try `jsonschema`, you can check the WebAssembly-powered [playground](https://jsonschema.dygalo.dev/) to see the results instantly.
## Highlights
- 📚 Full support for popular JSON Schema drafts
- 🔧 Custom keywords and format validators
- ⚡ Compile-time validators for Rust, Python and Ruby extension modules
- 🌐 Blocking & non-blocking remote reference fetching (network/file)
- 📦 Schema bundling into Compound Schema Documents, and `$ref` dereferencing
- 🎨 Structured Output v1 reports (flag/list/hierarchical)
- ✨ Meta-schema validation for schema documents, including custom metaschemas
- 🧮 Experimental schema canonicalization
- 🧩 Validation of custom in-memory JSON representations
- 🔗 Bindings for [Python](https://github.com/Stranger6667/jsonschema/tree/master/crates/jsonschema-py) and [Ruby](https://github.com/Stranger6667/jsonschema/tree/master/crates/jsonschema-rb)
- 🚀 WebAssembly support
- 💻 Command Line Interface
### Supported drafts
The following drafts are supported:
- [](https://bowtie.report/#/implementations/rust-jsonschema)
- [](https://bowtie.report/#/implementations/rust-jsonschema)
- [](https://bowtie.report/#/implementations/rust-jsonschema)
- [](https://bowtie.report/#/implementations/rust-jsonschema)
- [](https://bowtie.report/#/implementations/rust-jsonschema)
You can check the current status on the [Bowtie Report](https://bowtie.report/#/implementations/rust-jsonschema).
## Notable Users
- Tauri: [Config validation](https://github.com/tauri-apps/tauri/blob/c901d9fdf932bf7c3c77e9d3097fabb1fe0712af/crates/tauri-cli/src/helpers/config.rs#L173)
- Apollo Router: [Config file validation](https://github.com/apollographql/router/blob/855cf6cc0757ca6176970ddf3ae8c98c87c632d1/apollo-router/src/configuration/schema.rs#L120)
- qsv: [CSV record validation with custom keyword & format validator](https://github.com/jqnatividad/qsv/blob/6b6985065a1270f767d881b13aa2a27fae1958fb/src/cmd/validate.rs#L630)
## Performance
`jsonschema` outperforms other Rust JSON Schema validators in most scenarios. The numbers below are for the runtime validator, which compiles a schema into a reusable `Validator`:
- **75-692x** faster than `valico` and **10-78x** faster than `jsonschema_valid` for complex schemas (**>1,000,000x** on FHIR)
- Generally **2.8-40x** faster than `boon`, **>280x** on FHIR, and **>5000x** for recursive schemas
When the schema is known at build time, the `#[jsonschema::validator]` macro (`macros` feature) generates a specialized validator at compile time. This avoids schema compilation at runtime and validates roughly **2.3-10x** faster than the runtime validator across our benchmark schemas.
For detailed benchmarks, see our [full performance comparison](https://github.com/Stranger6667/jsonschema/tree/master/crates/benchmark-suite).
## Cargo features
| Feature | Default | Enables |
|---|---|---|
| `resolve-http` | ✅ | Fetching remote references over HTTP |
| `resolve-file` | ✅ | Reading references from the filesystem |
| `tls-aws-lc-rs` | ✅ | TLS provider for `resolve-http` |
| `idna` | ✅ | The `idn-hostname` and `idn-email` formats |
| `tls-ring` | | `ring` as the TLS provider instead of `aws-lc-rs` |
| `resolve-async` | | Non-blocking reference resolution |
| `arbitrary-precision` | | Arbitrarily large integers and exact decimal values |
| `macros` | | The `#[jsonschema::validator]` compile-time validator |
| `pyo3` | | Validating Python objects in place, and `backend = Pyo3` for the macro |
| `magnus` | | Validating Ruby objects in place, and `backend = Magnus` for the macro |
| `jsonb` | | Validating Postgres `jsonb` values in place |
Turning off `idna` drops the IDNA and ICU dependencies; `idn-hostname` and `idn-email` are then
treated as unknown formats.
## Minimum Supported Rust Version (MSRV)
This crate requires Rust 1.85.0 or later.
## TLS Configuration
By default, `jsonschema` uses `aws-lc-rs` as the TLS cryptography provider, which is the default one in `reqwest`.
### Using Ring Instead
You can opt into using `ring` as the TLS provider:
```toml
[dependencies]
jsonschema = {
version = "0.42",
default-features = false,
features = ["resolve-http", "resolve-file", "tls-ring"]
}
```
**NOTE:** If both `tls-aws-lc-rs` and `tls-ring` features are enabled, `aws-lc-rs` takes precedence.
## Acknowledgements
This library draws API design inspiration from the Python [`jsonschema`](https://github.com/python-jsonschema/jsonschema) package. We're grateful to the Python `jsonschema` maintainers and contributors for their pioneering work in JSON Schema validation.
## Support
If you have questions, need help, or want to suggest improvements, please use [GitHub Discussions](https://github.com/Stranger6667/jsonschema/discussions).
## Sponsorship
If you find `jsonschema` useful, please consider [sponsoring its development](https://github.com/sponsors/Stranger6667).
## Contributing
We welcome contributions! Here's how you can help:
- Share your use cases
- Implement missing keywords
- Fix failing test cases from the [JSON Schema test suite](https://bowtie.report/#/implementations/rust-jsonschema)
See [CONTRIBUTING.md](https://github.com/Stranger6667/jsonschema/blob/master/CONTRIBUTING.md) for more details.
## License
Licensed under [MIT License](https://github.com/Stranger6667/jsonschema/blob/master/LICENSE).