pglite-oxide 0.3.0

Rust helpers for embedding the Electric SQL pglite WebAssembly PostgreSQL runtime
Documentation

pglite-oxide

CI crates.io docs.rs MSRV License

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 path uses the bundled PGDATA template and compiled Wasmtime module cache. There are no startup flags to remember for ordinary apps.

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. Fresh databases are created from the bundled PGDATA template, and later process starts reuse the compiled module cache when possible.

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

Docs