SQLx

SQLx is the default store backend and supports SQLite and PostgreSQL.

Connect and build

Generate the schema as shown in installation, then connect the pool and supply the store:

use crate::auth_schema::{AppAuthSchema, run_app_migrations};
use better_auth::plugins::EmailPasswordPlugin;
use better_auth::sqlx::{SqlxPool, SqlxStore};
use better_auth::{AuthConfig, BetterAuth};

async fn build_auth(
    secret: &str,
    database_url: &str,
) -> Result<BetterAuth<AppAuthSchema>, Box<dyn std::error::Error>> {
    let config = AuthConfig::new(secret).base_url("http://localhost:3000");
    let pool = SqlxPool::connect(database_url).await?;
    run_app_migrations(&pool).await?;
    let store = SqlxStore::<AppAuthSchema>::new(config.clone(), pool);

    Ok(BetterAuth::<AppAuthSchema>::new(config)
        .store(store)
        .plugin(EmailPasswordPlugin::new())
        .build()
        .await?)
}

SqlxPool selects the engine from the URL. Use sqlx-sqlite or sqlx-postgres with default features disabled to select one engine; retain a TLS feature for outbound requests.

Existing models

Derive sqlx::FromRow and better_auth::sqlx::AuthEntity on your models. #[auth(table = "...")] selects a table; #[sqlx(rename = "...")] maps a column.

Use DateTime<Utc> for PostgreSQL TIMESTAMPTZ and NaiveDateTime for existing UTC TIMESTAMP columns. See existing databases before changing a schema’s timestamp representation.