Crate rusdantic 

Rusdantic

A high-ergonomics data validation and serialization framework for Rust, inspired by Python’s Pydantic.

Rusdantic bridges the gap between serde (serialization) and validation crates like validator / garde into a single, unified derive macro.

Quick Start

use rusdantic::prelude::*;

#[derive(Rusdantic, Debug)]
struct User {
    #[rusdantic(length(min = 3, max = 20))]
    username: String,

    #[rusdantic(email)]
    email: String,

    #[rusdantic(range(min = 18))]
    age: u8,
}

// Deserialize + validate in one step
let json = r#"{"username": "rust_ace", "email": "user@example.com", "age": 25}"#;
let user: User = rusdantic::from_json(json).unwrap();

// Or validate a manually constructed struct
let user = User {
    username: "ab".to_string(),
    email: "not-email".to_string(),
    age: 16,
};
assert!(user.validate().is_err());

Features

• Unified Derive Macro: #[derive(Rusdantic)] generates Serialize, Deserialize, and Validate in one shot.
• Validate-on-Deserialize: Validation runs during deserialization, so invalid structs never exist in memory when using from_json().
• Path-Aware Errors: Get precise error paths like user.addresses[0].zip_code for nested structures.
• 7 Built-in Validators: length, range, email, url, pattern, contains, required — plus custom validators.
• Serde Compatibility: Works with #[serde(rename)], #[serde(default)], and other serde attributes.
• JSON Schema Generation: Generate Draft 2020-12 / OpenAPI 3.1 schemas.
• PII Redaction: #[rusdantic(redact)] hides sensitive data in Debug output.
• Zero-Cost Abstractions: Validation logic is monomorphized at compile time.

Modules

prelude

Convenience prelude module for common imports.

types

Constrained types: PositiveInt, NonEmptyString, EmailStr, SecretStr, HttpUrl, etc.

Structs

DumpOptions

Options for controlling serialization output.

TypeAdapter

A standalone validator/serializer for any serde-compatible type.

ValidationError

A single validation error with location context.

ValidationErrors

A collection of validation errors from validating a struct.

Enums

PathSegment

Path segment in a validation error location.

RusdanticError

Error type for Rusdantic operations that may fail due to either deserialization errors (malformed JSON) or validation errors (valid JSON but invalid data).

Traits

Dump

Trait for types that support advanced serialization with options.

Validate

The core validation trait for Rusdantic.

Functions

from_json

Deserialize a JSON string into a validated struct.

from_json_with_limit

Deserialize a JSON string with an input size limit.

from_value

Deserialize a serde_json::Value into a validated struct.

Derive Macros

Rusdantic

Derive macro that generates Serialize, Deserialize, and Validate implementations for a struct.