Rust SDK Overview

The Lager Rust crate gives embedded developers first-class access to Lager nets. A hardware-in-the-loop (HIL) test suite can live next to your firmware and run with cargo test. No Python is required. The crate is a pure HTTP/JSON client of the Lager Box API. It covers:

power supplies, battery simulators, e-loads and solar simulators
GPIO, ADC, DAC, thermocouples, watt meters and energy analyzers
SPI, I2C, USB hub ports, robot arms, webcams and routers
oscilloscopes and YubiHSM 2 HSMs
nets that a custom driver on the box runs
streaming UART
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, because the bare lager name is taken by an unrelated crate. The library target is still 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 = "0.9" }

The crate requires Rust 1.75 or newer and builds on edition 2021. 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; `AsyncUart` when `async` is on too
`rtt`	no	RTT log streaming over the box’s Socket.IO namespace, for reading `defmt` output from a running target; `AsyncRttSession` when `async` is on too
`scope-trace`	no	Scope waveform samples: `Scope::capture()` and `Scope::stream()`

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

lager = { package = "lager-net", version = "0.9", 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
`FlashFailed`, `ProbeBusy`, `SafetyRefused`	A debug-probe operation failed in a way the crate names
`DfuFailed`	Box-side `dfu-util` exited non-zero
`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`	Kept for compatibility; no net type returns it
`UartInUse`	Another session holds the UART net or its serial device

Requirements

A Lager Box with software new enough to serve POST /net/command — check lager.status()?.capabilities.net_command, or run lager update. Newer calls need newer box software, and each page names the version. An older box returns Error::UnsupportedByBox.
Rust 1.75+.

Logic-analyzer nets are not on the box HTTP API yet. The work list is in the crate’s MISSING_ENDPOINTS.md.

Getting Started

Development

Power & Simulation

Measurement

I/O & Communication

Utilities

Security

Guides

Rust SDK Overview

Quickstart

Features

Errors

Requirements

Reference

Getting started

Firmware and debug

Power and simulation

Measurement

I/O and communication

Utilities

Security

Guides

​Quickstart

​Features

​Errors

​Requirements

​Reference

​Getting started

​Firmware and debug

​Power and simulation

​Measurement

​I/O and communication

​Utilities

​Security

​Guides

Quickstart

Features

Errors

Requirements

Reference

Getting started

Firmware and debug

Power and simulation

Measurement

I/O and communication

Utilities

Security

Guides