mik-sdk

Ergonomic SDK for building WASI HTTP handlers with pure Rust.

v0.1.x - Published and usable, but evolving. The API may change between minor versions.

Features

• Type-Safe Routing - routes! macro with path, query, and body extraction
• Derive Macros - #[derive(Type)], #[derive(Query)], #[derive(Path)]
• Response Helpers - ok!, error! with RFC 7807 support
• SQL Builder - sql_read!, sql_create! with cursor pagination
• Minimal - ~200KB composed component size

Quick Start

use mik_sdk::prelude::*;

// Define typed inputs with derive macros
#[derive(Type)]
pub struct HelloResponse {
    pub greeting: String,
    pub name: String,
}

#[derive(Path)]
pub struct HelloPath {
    pub name: String,
}

#[derive(Query)]
pub struct SearchQuery {
    pub q: Option<String>,
    #[field(default = 1)]
    pub page: u32,
    #[field(default = 10, max = 100)]
    pub limit: u32,
}

// Define routes with typed inputs
routes! {
    GET "/" => home,
    GET "/hello/{name}" => hello(path: HelloPath) -> HelloResponse,
    GET "/search" => search(query: SearchQuery),
}

fn home(_req: &Request) -> Response {
    ok!({ "message": "Welcome!" })
}

fn hello(path: HelloPath, _req: &Request) -> Response {
    ok!({
        "greeting": format!("Hello, {}!", path.name),
        "name": path.name
    })
}

fn search(query: SearchQuery, _req: &Request) -> Response {
    ok!({
        "query": query.q,
        "page": query.page,
        "limit": query.limit
    })
}

Core Macros

Response Macros

ok!({ "data": value })                    // 200 OK with JSON
error! { status: 404, title: "Not Found" } // RFC 7807 error
created!("/users/123", { "id": "123" })   // 201 Created with Location
no_content!()                              // 204 No Content

Routing

routes! {
    GET "/" => home,
    GET "/users/{id}" => get_user(path: Id) -> User,
    POST "/users" => create_user(body: CreateInput) -> User,
    GET "/search" => search(query: SearchQuery),
}

DX Macros

guard!(!name.is_empty(), 400, "Name required");      // Early return validation
let user = ensure!(find_user(id), 404, "Not found"); // Unwrap or return error

For JSON body parsing, use typed inputs with #[derive(Type)] - the body is parsed automatically in the route handler.

SQL Builder

let (sql, params) = sql_read!(users {
    select: [id, name, email],
    filter: { active: true },
    order: [-created_at, id],
    after: cursor,
    limit: 20,
});

HTTP Client

// Simple request
let resp = fetch!(GET "https://api.example.com/users").send()?;

// POST with JSON body
let resp = fetch!(POST "https://api.example.com/users", json: {
    "name": "Alice"
}).send()?;

// SSRF protection for user-provided URLs
let resp = fetch!(GET &user_url)
    .deny_private_ips()  // Blocks localhost, 10.x, 192.168.x, etc.
    .send()?;

Request Helpers

req.param("id")          // Path parameter: Option<&str>
req.query("page")        // Query parameter: Option<&str>
req.header("auth")       // Header (case-insensitive): Option<&str>
req.body()               // Raw body: Option<&[u8]>
req.text()               // Body as UTF-8: Option<&str>
req.is_json()            // Content-Type is JSON: bool
req.is_html()            // Content-Type is HTML: bool
req.is_form()            // Content-Type is form: bool
req.accepts("json")      // Accept header check: bool

Type Inference

Variables work directly in ok! and json! macros via the ToJson trait:

ok!({
    "name": name,       // String → JSON string
    "age": age,         // i32 → JSON integer
    "score": score,     // Option<f64> → JSON number or null
    "tags": tags        // Vec<&str> → JSON array
})

Type hints available for explicit control: str(), int(), float(), bool()

API Reference

Modules

Response Macros

DX Macros

SQL Macros

time Module

random Module

Request Methods

Logging

// Format-string style
log::info!("User {} logged in", id);
log::warn!("Cache miss: {}", key);
log::error!("Failed: {}", err);
log::debug!("Debug: {:?}", data);  // Compiled out in release

// Structured style (JSON output)
log!(info, "user created", id: user_id, email: &email);

Feature Flags

[dependencies]
mik-sdk = "0.1"  # Includes sql + http-client by default

# Minimal build
mik-sdk = { version = "0.1", default-features = false }

Configuration

Environment variables for runtime limits:

Requirements

• Rust 1.89+ (Edition 2024)
• Target: wasm32-wasip2
• Build tool: cargo-component

License

Licensed under MIT license. See LICENSE-MIT.