Introduction

Build, run, and deploy WASI HTTP handlers

mik is a batteries-included CLI for WASI HTTP projects. It handles building, composition, and running your WASM HTTP handlers with reliability features like circuit breakers, rate limiting, and JavaScript orchestration.

Note: mik is an experimental project for learning WASI P2 and the component model. Not yet battle-tested for production.

Why mik?

Challenge	mik Solution
Complex WASI runtimes	Single binary with embedded runtime
No built-in reliability	Circuit breaker, rate limiting, caching
Orchestration requires Rust	JavaScript/TypeScript via rquickjs
Multi-module scenarios	Route multiple handlers from one server

Key Features

• Single Binary - mik CLI includes the embedded runtime
• Reliability - Circuit breaker, rate limiting, graceful shutdown
• LRU Cache - Byte-aware module caching with configurable limits
• JavaScript Orchestration - Compose multiple WASM handlers via JS/TS scripts
• Static Files - Optional static file serving with MIME detection
• Prometheus Metrics - Built-in /metrics endpoint
• Gzip Compression - Automatic compression for large responses

Quick Start

# Install
cargo install mik

# Create project
mik new my-api
cd my-api

# Build and run (dev mode with watch + services)
mik build -rc
mik dev

Test: curl http://localhost:3000/run/my-api/

Architecture

Runtime Modes

Multi-Module Mode

Run multiple handlers from a directory:

mik run   # Uses mik.toml configuration

[server]
modules = "modules/"

Route	Handler
/run/auth/*	modules/auth.wasm
/run/users/*	modules/users.wasm
/run/orders/*	modules/orders.wasm
/static/*	Static files (if configured)
/health	Health check
/metrics	Prometheus metrics

Single Component Mode

Run a single component:

mik run dist/my-api-composed.wasm

Routes: /run/my-api/* -> component (name derived from filename)

The mik-sdk

Write handlers with typed, ergonomic Rust macros:

#[allow(warnings)]
mod bindings;

use bindings::exports::mik::core::handler::{self, Guest, Response};
use mik_sdk::prelude::*;

#[derive(Path)]
struct UserPath {
    id: u32,
}

routes! {
    GET "/" | "" => home,
    GET "/users/{id}" => get_user(path: UserPath),
}

fn home(_req: &Request) -> Response {
    ok!({
        "message": "Hello from mik!",
        "version": "0.1.0"
    })
}

fn get_user(path: UserPath, _req: &Request) -> Response {
    ok!({
        "id": path.id,
        "name": "Alice"
    })
}

Documentation

• Getting Started - Build your first handler
• Configuration - mik.toml reference
• Scripts - JavaScript orchestration
• Reliability - Circuit breaker, rate limiting
• CLI Reference - Command line tools
• Architecture - Technical design

Requirements

• Rust 1.85+
• cargo-component for building WASM
• wac-cli for composition

License

MIT