pglite-oxide

pglite-oxide embeds the Electric SQL PGlite WASI PostgreSQL runtime in Rust. It gives Rust apps a local Postgres-compatible database without shipping a native Postgres sidecar.

Use it when you want:

• local Postgres semantics in a Rust or Tauri app
• fast Postgres-backed tests without Docker or testcontainers
• a PostgreSQL connection URI for crates such as SQLx or tokio-postgres
• a small, embedded database boundary that stays on the Rust side of the app

The crate currently targets PostgreSQL 17.x PGlite builds, Rust 1.92+, and Wasmtime 44.

Install

cargo add pglite-oxide serde_json

The default runtime-cache feature enables Wasmtime's persistent compiled module cache. Disable default features only if your app cannot write to the global Wasmtime cache.

Direct Embedded API

Use Pglite when your Rust code owns the database calls.

use pglite_oxide::Pglite;
use serde_json::json;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut db = Pglite::open("./.pglite")?;

    db.exec("CREATE TABLE IF NOT EXISTS items(value TEXT)", None)?;
    db.query("INSERT INTO items(value) VALUES ($1)", &[json!("alpha")], None)?;

    let result = db.query("SELECT value FROM items", &[], None)?;
    println!("{:?}", result.rows);

    db.close()?;
    Ok(())
}

For tests, use Pglite::temporary()?. Temporary databases clone a process-local template cluster, so repeated tests avoid fresh initdb work.

PostgreSQL Client URI

Use PgliteServer when an existing library expects a PostgreSQL URL. Configure client pools with one connection because the embedded runtime owns one backend.

For SQLx:

cargo add sqlx --features postgres,runtime-tokio
cargo add tokio --features macros,rt-multi-thread

use pglite_oxide::PgliteServer;
use sqlx::{Connection, Row};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let server = PgliteServer::temporary_tcp()?;
    let mut conn = sqlx::PgConnection::connect(&server.connection_uri()).await?;

    let row = sqlx::query("SELECT $1::int4 + 1 AS answer")
        .bind(41_i32)
        .fetch_one(&mut conn)
        .await?;
    assert_eq!(row.try_get::<i32, _>("answer")?, 42);

    conn.close().await?;
    server.shutdown()?;
    Ok(())
}

For app persistence, use PgliteServer::builder().path("./.pglite").start()?.

Current Shape

pglite-oxide is a Wasmtime/WASI embedding of PGlite, not native libpglite bindings. The first process start can spend time compiling the large WASM module; later starts reuse Wasmtime cache state when the default feature is enabled.

Prefer the direct Pglite API when you do not need a PostgreSQL connection string. Use PgliteServer for compatibility with existing Postgres client crates.

Docs

• Usage guide
• Runtime and performance notes
• Tauri usage
• Development guide
• Runtime asset provenance
• Release process