Mewz

Mewz is a unikernel designed specifically for running Wasm applications and compatible with WASI.

What's new with Mewz

There are now various Wasm runtimes, but they operate on general-purpose operating systems such as Linux or Windows.

Mewz is a specialized kernel designed for running Wasm. Mewz runs a single Wasm application within the kernel by linking it together during the build process with the Wasm application. (A kernel composed in this manner is commonly referred to as a unikernel.) In this way, Mewz provides the minimal required features and environment for executing Wasm.

Quick Start

There are some example programs. Please check out examples.

Option1: Docker

We prepare for a Docker image that has a environment for running Mewz.

curl -o helloworld.wat https://raw.githubusercontent.com/Mewz-project/Wasker/main/helloworld.wat
docker run -v .:/volume ghcr.io/mewz-project/mewz helloworld.wat

This image internally run Wasker, build Mewz, and run it on QEMU.

Option2: Dev Container

You can use Dev Container on GitHub Codespaces or your local VSCode.

To start Codespaces,

• Click Code -> Codespaces -> New codespace on this repository page.
• Wait for a while, then you can see VSCode on browser.
• Open terminal on VSCode

# On the Dev Container
git submodule update --init
curl -o helloworld.wat https://raw.githubusercontent.com/Mewz-project/Wasker/main/helloworld.wat
wasker helloworld.wat
zig build -Dapp-obj=wasm.o run

Option3: Build from source

Compile a Wasm file into a native object file, using Wasker. Follow the instruction here.

Then, build Mewz and run it on QEMU with the following commands.

zig build -Dapp-obj=<path to the object file generated by Wasker> run

To use file systems, specify the directory by -Ddir=<path to dir>. See examples/static_file_server.

Warning

This option makes an archive of the directory by tar and attach it to QEMU.

Note

QEMU's port 1234 is mapped to localhost:1234.

Run integration tests

zig bulid -Dtest=true run

Current Status

Feature	Status
WASI Preview 1	In Progress: Partial Implementation (Please refer to #1)
Socket	✅ (WasmEdge Compatible)
Component Model	Not yet
File System	On memory, read only
Network	✅