wasmer

Lightweight sandboxes for your apps and AI agents Run with the CLI · Embed with the SDK · Try in your browser Wasmer runs your apps in fast, secure, and lightweight sandboxes: locally, in the cloud, or in your browser. Secure by default. You control file, network, and environment access. Lightweight. Fast startup with a small memory footprint. Ready to run. Python, JavaScript, Bash, and more from the registry. Embeddable. Add sandboxes to your app with the Wasmer SDK. Run your first sandbox Install the CLI on macOS or Linux: curl https://get.wasmer.io -sSfL | sh Windows and other installation options Windows (PowerShell) iwr https://win.wasmer.io -useb | iex Homebrew (macOS / Linux) brew install wasmer See the installation guide for more options. Run Python in a sandbox: wasmer run python/python -- -c "print('Hello from Wasmer')" Hello from Wasmer Or try a shell command and Cowsay: wasmer run wasmer/bash -- -c "echo 'Hello from Wasmer'" wasmer run syrusakbary/cowsay -- "Hello from Wasmer" Wasmer downloads the package and caches it for future runs. Use -- to separate Wasmer options from the arguments passed to your program. To work with local files, grant access to a directory with --volume; enable host networking with --net when your program needs it. See the CLI guide for details. No installation needed: open wasmer.sh to try a sandbox in your browser. Wasmer SDK Create a sandbox, choose your tools, and run code directly in your app with the Wasmer SDK. Install the SDK JavaScript / TypeScript (Node.js 20 or newer): npm install @wasmer/sdk Rust The Rust SDK currently uses a source dependency. Clone wasmerio/wasmer-sdk, then point your application at its rust directory: [dependencies] wasmer-sdk = { path = "../wasmer-sdk/rust" } tokio = { version = "1", features = ["macros", "rt-multi-thread"] } Follow the Rust setup guide for the required toolchain and workspace patches. Crates.io publishing is currently disabled. Python python -m pip install wasmer-sdk The SDK's Python wheels support macOS and Linux on Intel and ARM64. See the Python guide. Swift (iOS and macOS) Use Swift 6 or newer. The SDK supports macOS 12+ and iOS 27+; iOS apps require Xcode 27 or newer. Add the package to your Package.swift dependencies: .package( url: "https://github.com/wasmerio/wasmer-sdk.git", revision: "wasmer-sdk-swift-v0.4.0" ) Then add the product to your target's dependencies: .product(name: "WasmerSDK", package: "wasmer-sdk") In Xcode, you can instead add the repository URL, select wasmer-sdk-swift-v0.4.0 as a revision, and choose the WasmerSDK product. SwiftPM downloads the prebuilt macOS binaries and iOS runtime resources. For iOS, set the deployment target to iOS 27.0 and allow local networking in your app's Info.plist: <key>NSAppTransportSecurity</key> <dict> <key>NSAllowsLocalNetworking</key> <true/> </dict> Both platforms use import WasmerSDK and the same API. On iOS, the SDK manages a hidden WKWebView; your app does not need to display one. See the Swift guide and iOS setup guide for more details. Run code in a sandbox JavaScript / TypeScript Save this as sandbox.mjs: import { Wasmer } from "@wasmer/sdk/node"; const wasmer = new Wasmer(); const sandbox = await wasmer.sandboxes.create({ packages: ["python/python@=3.13.20"], }); const output = await sandbox .command("python", ["-c", "print('Hello from Wasmer')"]) .run(); console.log(output.text()); Run it with node sandbox.mjs. Python executes inside the sandbox; you don't need Python installed on the host. See the JavaScript guide. Python example Save this as sandbox.py: import asyncio from wasmer_sdk import Wasmer async def main(): wasmer = Wasmer() sandbox = await wasmer.sandboxes.create( packages=["python/python@=3.13.20"], ) output = await sandbox.command( "python", ["-c", "print('Hello from Wasmer')"] ).run() print(output.text()) asyncio.run(main()) Run it with python sandbox.py. See the Python guide. Swift example (iOS and macOS) Use this code in an async throws context: import WasmerSDK let wasmer = try Wasmer() let sandbox = try await wasmer.sandboxes.create( packages: ["python/python@=3.13.20"] ) let output = try await sandbox.command( "python", ["-c", "print('Hello from Swift!')"] ).run(timeout: 30) print(try output.text()) See the Swift guide for embedding in an iOS or macOS app and more examples. JavaScript in the browser Use the same JavaScript sandbox API with the @wasmer/sdk/browser import. Execution happens in the browser. Your page needs cross-origin isolation (Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp) for worker-backed execution. Follow the browser setup guide or explore wasmer.sh. Rust example use wasmer_sdk::{Result, Wasmer}; #[tokio::main] async fn main() -> Result<()> { let wasmer = Wasmer::new()?; let sandbox = wasmer .sandboxes() .create() .package("python/python@=3.13.20") .await?; let output = sandbox .command("python") .args(["-c", "print('Hello from Wasmer')"]) .run() .await?; println!("{}", output.text()?); Ok(()) } See the Rust guide for workspace setup and more examples. Go further Build more with the sandbox API: Commands. Run code and capture output. Processes. Stream output and manage long-running tasks. Files. Read and write the sandbox workspace. Tools. Combine languages and packages in one sandbox. Services. Run servers with explicit network access. The SDK is currently alpha. See the language guides for platform support and capabilities, and the SDK examples for Python scripts, an Edge.js HTTP server, PostgreSQL, and multiple tools sharing one sandbox. Software you can run Start with packages from the registry: Software Package Python python/python JavaScript / Node.js-compatible app