Prax

A next-generation, type-safe ORM for Rust

Features • Installation • Quick Start • Documentation • License

Prax is a modern, Prisma-inspired ORM for Rust with first-class async support. Built on top of tokio-postgres, sqlx, and other async database clients, Prax provides a type-safe, ergonomic API for database operations with compile-time guarantees.

⚠️ Work in Progress - Prax is currently under active development. See TODO.md for the implementation roadmap.

Features

• 🔒 Type-Safe Queries - Compile-time checked queries with zero runtime overhead
• ⚡ Async-First - Built on Tokio for high-performance async I/O
• 🎯 Fluent API - Intuitive query builder with method chaining
• 🔗 Relations - Eager and lazy loading with include and select
• 📦 Migrations - Schema diffing, SQL generation, and migration tracking
• 🛠️ Code Generation - Proc-macros for compile-time model generation
• 🗄️ Multi-Database - PostgreSQL, MySQL, and SQLite support
• 🔌 Framework Integration - First-class support for Armature, Axum, and Actix-web

Installation

Add Prax to your Cargo.toml:

[dependencies]
prax = "0.1"
tokio = { version = "1", features = ["full"] }

For specific database backends:

# PostgreSQL (default)
prax = { version = "0.1", features = ["postgres"] }

# MySQL
prax = { version = "0.1", features = ["mysql"] }

# SQLite
prax = { version = "0.1", features = ["sqlite"] }

# Armature framework integration
prax-armature = "0.1"

Quick Start

Define Your Models

use prax::prelude::*;

#[derive(Model)]
#[prax(table = "users")]
pub struct User {
    #[prax(id, auto_increment)]
    pub id: i32,

    #[prax(unique)]
    pub email: String,

    pub name: Option<String>,

    #[prax(default = "now()")]
    pub created_at: DateTime<Utc>,

    #[prax(relation(has_many))]
    pub posts: Vec<Post>,
}

#[derive(Model)]
#[prax(table = "posts")]
pub struct Post {
    #[prax(id, auto_increment)]
    pub id: i32,

    pub title: String,

    pub content: String,

    #[prax(relation(belongs_to))]
    pub author: User,

    pub author_id: i32,
}

Connect and Query

use prax::prelude::*;

#[tokio::main]
async fn main() -> Result<(), prax::Error> {
    // Connect to database
    let client = PraxClient::new("postgresql://localhost/mydb").await?;

    // Find many with filtering and relations
    let users = client
        .user()
        .find_many()
        .where(user::email::contains("@example.com"))
        .include(user::posts::fetch())
        .order_by(user::created_at::desc())
        .take(10)
        .exec()
        .await?;

    // Create a new user
    let user = client
        .user()
        .create(user::Create {
            email: "hello@example.com".into(),
            name: Some("Alice".into()),
            ..Default::default()
        })
        .exec()
        .await?;

    // Update with filtering
    let updated = client
        .user()
        .update_many()
        .where(user::created_at::lt(Utc::now() - Duration::days(30)))
        .data(user::Update {
            name: Some("Inactive User".into()),
            ..Default::default()
        })
        .exec()
        .await?;

    // Transactions
    client
        .transaction(|tx| async move {
            let user = tx.user().create(/* ... */).exec().await?;
            tx.post().create(/* ... */).exec().await?;
            Ok(())
        })
        .await?;

    Ok(())
}

Armature Framework Integration

Prax integrates seamlessly with Armature, providing dependency injection support:

use armature::prelude::*;
use prax_armature::PraxModule;

#[module_impl]
impl DatabaseModule {
    #[provider(singleton)]
    async fn prax_client() -> Arc<PraxClient> {
        Arc::new(
            PraxClient::new("postgresql://localhost/mydb")
                .await
                .expect("Database connection failed")
        )
    }
}

#[controller("/users")]
impl UserController {
    #[get("/")]
    async fn list(
        &self,
        #[inject] db: Arc<PraxClient>,
    ) -> Result<Json<Vec<User>>, HttpError> {
        let users = db.user().find_many().exec().await?;
        Ok(Json(users))
    }
}

Query Operations

Filtering

// Equals
user::email::equals("alice@example.com")

// Contains, starts with, ends with
user::name::contains("alice")
user::email::starts_with("admin")
user::email::ends_with("@company.com")

// Comparisons
user::age::gt(18)
user::age::gte(21)
user::age::lt(65)
user::created_at::lte(Utc::now())

// Logical operators
and![
    user::age::gte(18),
    user::status::equals("active")
]

or![
    user::role::equals("admin"),
    user::role::equals("moderator")
]

not!(user::banned::equals(true))

// Nested relation filters
user::posts::some(post::published::equals(true))

Pagination

// Offset-based
client.user().find_many().skip(20).take(10).exec().await?;

// Cursor-based
client.user().find_many().cursor(user::id::equals(100)).take(10).exec().await?;

Aggregations

let count = client.user().count().exec().await?;

let stats = client
    .post()
    .aggregate()
    .count()
    .avg(post::views)
    .sum(post::likes)
    .exec()
    .await?;

let grouped = client
    .user()
    .group_by(user::country)
    .count()
    .exec()
    .await?;

Architecture

Prax is organized as a workspace of focused crates:

prax/
├── prax-core/           # Core types, traits, and abstractions
├── prax-schema/         # Schema parser and AST
├── prax-codegen/        # Proc-macro crate for code generation
├── prax-query/          # Query builder implementation
├── prax-postgres/       # tokio-postgres query engine
├── prax-mysql/          # mysql_async query engine
├── prax-sqlite/         # rusqlite query engine
├── prax-migrate/        # Migration engine
├── prax-cli/            # CLI tool
├── prax-armature/       # Armature framework integration
└── prax/                # Main crate re-exporting everything

CLI

Prax includes a CLI for schema management and migrations:

# Install the CLI
cargo install prax-cli

# Initialize a new Prax project
prax init

# Generate client from schema
prax generate

# Create a migration
prax migrate dev --name add_users_table

# Apply migrations
prax migrate deploy

# Reset database
prax migrate reset

# Introspect existing database
prax db pull

Comparison

Contributing

Contributions are welcome! Please read the contributing guidelines before submitting a pull request.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Copyright (c) 2025 Pegasus Heavy Industries LLC

Acknowledgments

Prax is heavily inspired by:

• Prisma - For pioneering the modern ORM developer experience
• Diesel - For proving type-safe database access in Rust is possible
• SeaORM - For async ORM patterns in Rust
• Armature - Our companion HTTP framework