zenoh-nostd

Zero Network Overhead. Async. No std. No alloc. Pure Rust.

async • bare-metal • no_std • zenoh

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📦 Overview

⚠️ This project is in early development.

zenoh-nostd is a Rust-native, async, #![no_std], no_alloc library that provides a zero-overhead network abstraction layer for ultra-constrained and bare-metal environments. In other terms you can run this bare metal on your favourite microcontroller.

⚡ Built on the Zenoh protocol, but stripped to the bone for minimalism and raw performance.

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✨ Features

• #![no_std]: No reliance on the Rust standard library.
• No dynamic allocation: Fully no_alloc, ideal for bare-metal targets.
• Deterministic: No heap, no surprises.
• Safe Rust: Entirely memory-safe.
• Testable: Supports both embedded and native testing environments.
• Embassy Integration: Seamlessly integrates with the Embassy async runtime for embedded systems.
• Broker: A #![no_std] broker to broke multiple zenoh clients with an optional gateway to a zenoh network.

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🔧 Installation

Add this to your Cargo.toml:

[dependencies]
zenoh-nostd = { git = "https://github.com/ZettaScaleLabs/zenoh-nostd" }

For embedded systems, ensure your crate uses #![no_std]:

#![no_std]

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🔌 Integration

Minimal Example

Here’s a simple example of sending a payload with zenoh-nostd:

async fn entry(spawner: embassy_executor::Spawner) -> zenoh::ZResult<()> {
    let config = init_session_example(&spawner).await;
    let mut resources = Resources::default();
    let session = zenoh::connect(&mut resources, &config, Endpoint::try_from(ENDPOINT)?).await?;

    let ke = zenoh::keyexpr::new("demo/example")?;
    let payload = b"Hello, from no-std!";
    
    session.put(ke, payload).finish().await?;
    
    Ok(())
}

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🔬 MSRV

🛠️ Minimum Supported Rust Version: Currently 1.91.0

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⚠️ Limitations

• No serial support yet. (#11)
• Interest protocol not implemented yet. (#46)

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🧪 Building and Testing

This project uses just for task management. Use just check to check the project and examples, just test to run the tests and just bench to run the benchmarks.

🔍 Pull requests that slow down the bench should be avoided.

Testing Examples

Use the following command structure:

just <platform> <example> [optional features]

• Platforms: std, wasm, esp32s3
• Examples: z_get, z_open, z_ping, z_pong, z_pub, z_pub_thr, z_put, z_querier, z_queryable, z_sub, , z_sub_thr,
• Broker: z_broker (with alloc feature)

Set the ENDPOINT=<endpoint> environment variable to specify the endpoint (default is tcp/127.0.0.1:7447). Set LISTEN=1 to specify the connection method.

For esp32s3, you must also provide:

• WIFI_SSID (default is ZettaScale).
• WIFI_PASSWORD (no default, must be provided).

See the ESP32 setup documentation for toolchain and target installation.

Example of few commands:

ENDPOINT=tcp/127.0.0.1:7447 just std z_pub

WIFI_PASSWORD=* ENDPOINT=tcp/192.168.21.1:7447 just esp32s3 z_sub

Example: Local TCP

Run a Zenoh router with:

zenohd -l tcp/127.0.0.1:7447

In two terminals:

# Terminal 1
just std z_pub

# Terminal 2
just std z_sub

Example: WebSocket + WASM

Run a Zenoh router with:

zenohd -l tcp/127.0.0.1:7447 -l ws/127.0.0.1:7446

Then:

# Terminal 1 (WASM)
ENDPOINT=ws/127.0.0.1:7446 just wasm z_pub

# Terminal 2 (STD)
just std z_sub

📦 Note: For WASM, ensure you have:

• wasm32-unknown-unknown target
• wasm-bindgen-cli
• basic-http-server (or similar)

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📁 Project Layout

zenoh-nostd/            # Git repository root
├── crates/
│   ├── zenoh-derive/   # Derive macros
│   ├── zenoh-nostd/    # Zenoh with IO, embassy
│   ├── zenoh-proto/    # Zenoh Protocol
│   └── zenoh-sansio/   # Zenoh Sans-IO objects (Transport only right now)
│
├── examples/
│   ├── web/
│   │   └── index.html  # File to test wasm example
│   │
│   ├── z_broker.rs     # Example with std/wasm/embassy io
│   ├── z_get.rs        # Example with std/wasm/embassy io
│   ├── z_open.rs       # Example with std/wasm/embassy io
│   ├── z_ping.rs       # Example with std/wasm/embassy io
│   ├── z_pong.rs       # Example with std/wasm/embassy io
│   ├── z_pub.rs        # Example with std/wasm/embassy io
│   ├── z_pub_thr.rs    # Example with std/wasm/embassy io
│   ├── z_put.rs        # Example with std/wasm/embassy io
│   ├── z_querier.rs    # Example with std/wasm/embassy io
│   ├── z_queryable.rs  # Example with std/wasm/embassy io
│   ├── z_sub.rs        # Example with std/wasm/embassy io
│   └── z_sub_thr.rs    # Example with std/wasm/embassy io
│
├── platforms/          # Platform-specific implementations
│   ├── zenoh-embassy/  # Embassy platforms (no_std)
│   ├── zenoh-std/      # Standard platforms (std)
│   └── zenoh-wasm/     # WASM32 platforms (wasm)
│
├── Cargo.toml          # Workspace + example package
└── src/
    └── lib.rs          # Example lib.rs

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📚 Documentation

The base project has been implemented in (#6) The structure and API have been reworked in (#34) The API has been reworked (#52)