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](https://wasmer.io/explore).
- **Embeddable**. Add sandboxes to your app with the [Wasmer SDK](#wasmer-sdk).
## Run your first sandbox
Install the CLI on macOS or Linux:
```sh
curl https://get.wasmer.io -sSfL | sh
```
Windows and other installation options
**Windows (PowerShell)**
```powershell
iwr https://win.wasmer.io -useb | iex
```
**Homebrew (macOS / Linux)**
```sh
brew install wasmer
```
See the [installation guide](https://docs.wasmer.io/install/) for more options.
Run Python in a sandbox:
```sh
wasmer run python/python -- -c "print('Hello from Wasmer')"
```
```text
Hello from Wasmer
```
Or try a shell command and Cowsay:
```sh
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](https://docs.wasmer.io/runtime/cli/) for details.
**No installation needed:** open [wasmer.sh](https://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](https://github.com/wasmerio/wasmer-sdk).
### Install the SDK
**JavaScript / TypeScript** (Node.js 20 or newer):
```sh
npm install @wasmer/sdk
```
Rust
The Rust SDK currently uses a source dependency. Clone
[`wasmerio/wasmer-sdk`](https://github.com/wasmerio/wasmer-sdk), then point your
application at its `rust` directory:
```toml
[dependencies]
wasmer-sdk = { path = "../wasmer-sdk/rust" }
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }
```
Follow the [Rust setup guide](https://github.com/wasmerio/wasmer-sdk/tree/main/rust)
for the required toolchain and workspace patches. Crates.io publishing is
currently disabled.
Python
```sh
python -m pip install wasmer-sdk
```
The SDK's Python wheels support macOS and Linux on Intel and ARM64.
See the [Python guide](https://github.com/wasmerio/wasmer-sdk/tree/main/python).
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:
```swift
.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:
```swift
.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`:
```xml
NSAppTransportSecurity
NSAllowsLocalNetworking
```
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](https://github.com/wasmerio/wasmer-sdk/tree/main/swift) and
[iOS setup guide](https://github.com/wasmerio/wasmer-sdk/tree/main/swift/WasmerWKSDK#add-to-an-app)
for more details.
### Run code in a sandbox
**JavaScript / TypeScript**
Save this as `sandbox.mjs`:
```javascript
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](https://github.com/wasmerio/wasmer-sdk/tree/main/js).
Python example
Save this as `sandbox.py`:
```python
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](https://github.com/wasmerio/wasmer-sdk/tree/main/python).
Swift example (iOS and macOS)
Use this code in an `async throws` context:
```swift
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](https://github.com/wasmerio/wasmer-sdk/tree/main/swift)
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](https://github.com/wasmerio/wasmer-sdk/tree/main/js#browser)
or explore [wasmer.sh](https://wasmer.sh).
Rust example
```rust
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](https://github.com/wasmerio/wasmer-sdk/tree/main/rust)
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](https://github.com/wasmerio/wasmer-sdk#what-can-you-run)
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`](https://wasmer.io/python/python) |
| JavaScript / Node.js-compatible apps | [`wasmer/edgejs`](https://wasmer.io/wasmer/edgejs) |
| Bash | [`wasmer/bash`](https://wasmer.io/wasmer/bash) |
| PHP | [`php/php`](https://wasmer.io/php/php) |
| PostgreSQL | [`wasmer/pglite`](https://wasmer.io/wasmer/pglite) |
| SQLite | [`sqlite/sqlite`](https://wasmer.io/sqlite/sqlite) |
| FFmpeg | [`wasmer/ffmpeg`](https://wasmer.io/wasmer/ffmpeg) |
[Explore more packages](https://wasmer.io/explore),
[package your own software](https://docs.wasmer.io/registry/get-started/), or
[deploy an application to Wasmer Edge](https://docs.wasmer.io/edge/get-started/).
## Develop and contribute
This repository contains the Wasmer runtime and CLI that power the sandbox
experience. The sandbox SDKs live in
[`wasmerio/wasmer-sdk`](https://github.com/wasmerio/wasmer-sdk).
For lower-level WebAssembly embedding, see the [Rust API](https://docs.rs/wasmer/)
and [C API](./lib/c-api).
- [Build Wasmer from source](./docs/BUILD.md)
- [Test your changes](./docs/TEST.md)
- [Report a security issue](./docs/SECURITY.md)
- [Open an issue](https://github.com/wasmerio/wasmer/issues)
Contributions are welcome. For guidance on getting started, read
[Contributing to Complex Projects](https://mitchellh.com/writing/contributing-to-complex-projects).
Wasmer is [MIT licensed](./LICENSE).
## Community
Get help, share what you're building, and meet other Wasmer users:
[Discord](https://discord.gg/rWkMNStrEW) ·
[X](https://x.com/wasmerio) ·
[LinkedIn](https://www.linkedin.com/company/wasmerio) ·
[Blog](https://wasmer.io/posts)
Community translations (may describe an earlier version)
[中文](./docs/cn/README.md) ·
[Deutsch](./docs/de/README.md) ·
[Español](./docs/es/README.md) ·
[Français](./docs/fr/README.md) ·
[日本語](./docs/ja/README.md) ·
[한국어](./docs/ko/README.md)
