Rust SDK Overview

The Lager Rust crate gives embedded developers first-class access to Lager nets, so a hardware-in-the-loop (HIL) test suite can live next to your firmware and run with cargo test — no Python required. The crate is a pure HTTP/JSON client of the Lager Box API: power supplies, battery simulators, e-loads, solar simulators, GPIO, ADC, DAC, thermocouples, watt meters, energy analyzers, SPI, I2C, USB hub ports, robot arms, webcams, routers, and streaming UART — plus the box-level capabilities (its own BLE adapter, WiFi interface, and BluFi ESP32 provisioning). Debug-probe nets (flash / erase / reset / memory reads / RTT) talk to the box’s debug service.

The package publishes on crates.io as lager-net (the bare lager name is taken by an unrelated crate), but the library target is named lager, so your code reads use lager::LagerBox;. Full API reference lives on docs.rs/lager-net.

Quickstart

Add the crate to your firmware project’s dev-dependencies:

# Cargo.toml
[dev-dependencies]
lager = { package = "lager-net", version = "0.2" }

Write a test:

// tests/boot.rs
use lager::{LagerBox, Level};

#[test]
fn dut_boots_at_3v3() -> lager::Result<()> {
    let lager = LagerBox::from_env()?; // reads LAGER_BOX_HOST
    let supply = lager.supply("supply1");
    let boot_ok = lager.gpio("boot_ok");

    supply.set_voltage(3.3)?;
    supply.enable()?;

    // Hardware-timed wait on the box; returns elapsed seconds.
    let t = boot_ok.wait_for_level(Level::High, 5.0)?;
    println!("booted in {t:.3}s");

    supply.disable()
}

Run it:

LAGER_BOX_HOST=192.168.1.42 cargo test

LagerBox::connect("hostname-or-ip") also works, with an optional host:port or full URL.

Features

Feature	Default	What you get
`blocking`	yes	`LagerBox` on `ureq` — tiny dependency tree, no tokio
`async`	no	`AsyncLagerBox` on `reqwest`/tokio; same methods, `.await`ed
`uart`	no	`Uart` streaming sessions over the box’s Socket.IO `/uart` namespace

Both clients execute the exact same request builders and response parsers, so the two transports cannot drift apart.

lager = { package = "lager-net", version = "0.2", features = ["async"] }

Errors

Everything returns lager::Result<T> with a single Error enum:

Variant	Meaning
`Connection`	Box unreachable (network/Tailscale/box offline)
`Timeout`	The box stalled past the (already widened) budget
`Box { status, message }`	The box refused or the hardware failed
`UnsupportedByBox`	HTTP 501: the box image predates this endpoint; update the box
`AuthRequired`	The box’s gateway wants a bearer token and none is available
`NotSupportedByBox`	The net type is a documented stub (see the note below)

Requirements

A Lager Box with software new enough to serve POST /net/command — check lager.status()?.capabilities.net_command, or run lager box update.
Rust 1.75+.

Oscilloscope / logic-analyzer workflows are not exposed on the box HTTP API yet, so Scope ships as a documented stub whose methods return Error::NotSupportedByBox. Support lands when the box API does; the endpoint sketch is tracked in the crate’s MISSING_ENDPOINTS.md.

Next steps

Net types — every handle the crate exposes
Testing guide — structuring a cargo test HIL suite, parallelism, CI
Debug probes & UART — flashing, RTT, and streaming serial
Authentication — boxes behind an authenticating gateway

Getting Started

Guides

Rust SDK Overview

Quickstart

Features

Errors

Requirements

Next steps

​Quickstart

​Features

​Errors

​Requirements

​Next steps

Quickstart

Features

Errors

Requirements

Next steps