Quickstart

Install the crate and parse, validate and serialize your first Rust model.

Parse a JSON document, normalize its fields and return a validated Rust value. This is the starting point for every integration.

Define→Parse & validate→Serialize

Choose your version

These examples target Rydantic 0.7.0 stable. Review the release notes for the breaking explicit-derive contract when upgrading from 0.6.0. For older deployments, use the 0.6.0 tagged guide.

Add the dependency

Cargo.toml

[dependencies]
rydantic = "=0.7.0"

Define your first model

src/main.rs

use rydantic::{Model, SchemaMode};

#[derive(Debug, Model)]
#[model(extra = "forbid")]
struct User {
    #[model(trim, min_length = 3, max_length = 30)]
    name: String,

    #[model(coerce, ge = 18, le = 120)]
    age: u8,

    #[model(trim, lowercase, email)]
    email: String,

    #[model(default)]
    tags: Vec<String>,

    note: Option<String>,
}

fn main() -> Result<(), rydantic::ValidationErrors> {
    let user = User::parse_json(
        r#"{"name":" Alice ","age":"25","email":" [e-mail] "}"#,
    )?;

    assert_eq!(user.name, "Alice");
    assert_eq!(user.age, 25);
    assert_eq!(user.email, "[e-mail]");
    println!("{}", user.dump_json()?);

    let schema = User::json_schema(SchemaMode::Output);
    assert!(schema.is_object());
    Ok(())
}

Model also generates Serde’s Serialize and Deserialize implementations. Derive Model once per model. Deserialization runs full validation, and serialization revalidates the current object.

Run an example

From the source checkout, run the model or tool-call examples:

cargo run -p rydantic --example user
cargo run -p rydantic --example tool_call
cargo run -p rydantic --example tool_call -- --schema
cargo run -p rydantic --example tool_call -- '{"kind":"ping"}'

Next steps

Validation rules

Explore constraints, defaults and normalization.

Follow the tutorials

Build a model, CRUD API and typed AI agent step by step.

Run an example

Find feature flags, complete programs and expected output.

Optional integrations

Enable HTTP, SQL, Cap’n Proto and other features.