NEAR Sandbox (Rust Edition)

Rust library for running a local NEAR node for development and testing.

Release Notes

Release notes can be found in the CHANGELOG.

Requirements

• Rust v1.85.0 or newer.
• MacOS (ARM64) or Linux (x86) for sandbox execution.

What is NEAR Sandbox?

NEAR Sandbox is a custom build of the NEAR blockchain, optimized for local development and testing.
If you're familiar with Ganache for Ethereum, this serves a similar purpose for NEAR.

This library provides a Rust API to easily start and configure your local NEAR Sandbox instance. The sandbox binary is automatically downloaded and managed for you.

There are near-sandbox packages available in other programming languages, see here.

Installation

Add near-sandbox to your [dependencies] or [dev-dependencies]:

cargo add near-sandbox

Simple Testing Example

use near_sandbox::Sandbox;

#[tokio::test]
async fn test_basic_sandbox() -> Result<(), Box<dyn std::error::Error>> {
    // Start a sandbox instance
    let sandbox = Sandbox::start_sandbox().await?;

    // Your test code here
    // The sandbox will be automatically cleaned up when it's dropped

    Ok(())
}

Examples

More examples can be found in the examples/ directory.

Features

• Easy sandbox startup: Start a local NEAR node with default or custom configuration.
• Version selection: Choose a specific NEAR Sandbox version.
• Custom configuration: Configure the config.json and genesis.json for your near-sandbox instance.
• Automatic binary management: The required sandbox binary is downloaded and managed automatically.
• RPC access: Interact with your sandbox node via its RPC endpoint.
• Environment variable configuration: Control binary source, logging, and timeouts via environment variables.

Starting a Sandbox

use near_sandbox::{Sandbox, SandboxConfig};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Start with default configuration
    let sandbox = Sandbox::start_sandbox().await?;

    // Or with a specific version
    let sandbox = Sandbox::start_sandbox_with_version("2.6.3").await?;

    // Or with custom configuration
    let config = SandboxConfig::default();
    let sandbox = Sandbox::start_sandbox_with_config(config).await?;

    // Or with both custom config and version
    let sandbox = Sandbox::start_sandbox_with_config_and_version(config, "2.6.3").await?;

    // The sandbox is automatically cleaned up when dropped
    Ok(())
}

Accessing RPC

use near_sandbox::Sandbox;

#[tokio::test]
async fn test_rpc_access() -> Result<(), Box<dyn std::error::Error>> {
    let sandbox = Sandbox::start_sandbox().await?;

    // Access the RPC endpoint
    let rpc_url = &sandbox.rpc_addr;
    println!("Sandbox RPC available at: {}", rpc_url);

    // Make RPC calls to your sandbox
    // ...

    Ok(())
}

Configuring RPC

use near_sandbox::{GenesisAccount, Sandbox, SandboxConfig};
use serde_json::json;

#[tokio::test]
async fn test_custom_rpc_config() -> Result<(), Box<dyn std::error::Error>> {
    let alice_genesis = GenesisAccount {
        account_id: "alice.near".to_string(),
        // You can also use `near_api::signer::get_secret_key()` and `signer.public_key()`
        public_key: "ed25519:AzBN9XwQDRuLvGvor2JnMitkRxBxn2TLY4yEM3othKUF".to_string(),
        private_key: "ed25519:5byt6y8h1uuHwkr2ozfN5gt8xGiHujpcT5KyNhZpG62BrnU51sMQk5eTVNwWp7RRiMgKHp7W1jrByxLCr2apXNGB".to_string(),
        // You can also use `NearToken::from_near(1000).as_yoctonear()`
        balance: 10_00u128 * 10u128.pow(24),
    };

    let config = SandboxConfig {
        additional_genesis: Some(json!({ "epoch_length": 100 })),
        additional_accounts: vec![alice_genesis.clone()],
        additional_config: Some(json!({ "network": { "trusted_stun_servers": [] } })),
        max_payload_size: None,
        max_open_files: None,
    };

    let sandbox = Sandbox::start_sandbox_with_config(config).await?;

    // Test of your custom sandbox instance
    // ...

    Ok(())
}

Automatic near-sandbox Binary Management

1. When you start a sandbox, the appropriate binary for your platform is automatically downloaded if it is not already present.
2. The sandbox process runs in the background.
3. When the Sandbox struct is dropped, the process is automatically killed.

Environment Variables

Customize sandbox behavior with these environment variables:

• SANDBOX_ARTIFACT_URL: Override the download link for neard. Useful if you have trouble downloading from the default IPFS gateway.
• NEAR_RPC_TIMEOUT_SECS: Set the timeout (in seconds) for waiting for the sandbox to start (default: 10).
• NEAR_SANDBOX_BIN_PATH: Use your own pre-built neard-sandbox binary instead of the default. Be careful not to use NodeJs package!
• NEAR_ENABLE_SANDBOX_LOG: Set to 1 to enable sandbox logging of near-sandbox (helpful for debugging).
• NEAR_SANDBOX_LOG: Specify custom log levels for the sandbox (forwarded to the RUST_LOG environment variable).
• NEAR_SANDBOX_LOG_STYLE: Specify custom log style for the sandbox (forwarded to the RUST_LOG_STYLE environment variable).

API Reference

API documentation is available at docs.rs/near-sandbox.