wdsm

wdsm is a poor man's attempt to make a FaaS runtime via WASM Component Model. It takes a config file and program file (currently JavaScript files), makes WebAssembly Interface Types (.wit) file, compiles WASM files, and then serves then through the endpoint defined in config.

Requirements

• Rust
• Node.js + npm (for jco)
• @bytecodealliance/jco installed globally

Install jco:

npm install -g @bytecodealliance/jco

Install / Build

Build the CLI and make wdsm available:

cargo install --path cli

Alternatively, build in-place:

cargo build --release

Quick start

Try the included examples.

1. Hello

wdsm deploy --config examples/hello/config.yml

# from another terminal
curl "http://127.0.0.1:3001/hello?name=World"
# -> Hello, World!

2. Addition (query params)

wdsm deploy --config examples/add/config.yml

# from another terminal
curl "http://127.0.0.1:3001/add?a=69.0&b=0.420"
# -> 69.420

3. Networking Example

wdsm deploy --config examples/ts/net/config.yml

curl -X POST http://127.0.0.1:3005/net -H "Content-Type: application/json" -d '{"msg": "Hello WASI!", "request_catcher": "heyjude"}'

Configuration File

Below is an example of a configuration file with optional WASI capabilities:

name: net
language: typescript
entrypoint: net.ts
entrypoint_function: net
port: 3005
endpoint: /net
method: POST
payload:
  - msg: string
  - request_catcher: string
return_type: string

capabilities:
  stdio: true            # Inherit stdio for logging (default: true)
  env:
    inherit: false       # Inherit host environment variables (default: false)
    vars:                # Explicit environment variables to expose
      - API_KEY
  network:               # WASI network capabilities (default: false for security)
    http: true           # Enable WASI HTTP outbound client
    tcp: true            # Allow TCP sockets
    udp: false           # Allow UDP sockets
    dns: true            # Allow DNS resolution
  filesystem:            # WASI filesystem volume
    - host: "./data"
      guest: "/data"
      read_only: true

Supported basic types: string|str, int|i32, i64, float|f32, f64, boolean|bool.

Features

• WASI capability sandboxing configurable per endpoint via capabilities in config.yml.
• Outbound WASI networking & HTTP client support (fetch in JS/TS, urllib/HTTP in Python) enabled declaratively via capabilities.network.http.

Limitations

• very much limited

License

See LICENSE.