tinywasm/fetch

A minimal, zero-dependency, WASM-compatible HTTP client for Go.

Features

• Tiny API: Get, Post, Put, Delete
• Declarative Headers: ContentTypeJSON(), ContentTypeBinary(), etc.
• WASM Compatible: Works in browsers using fetch API and in standard Go
• Async Support: Send (callback) and Dispatch (fire-and-forget)

Installation

go get github.com/tinywasm/fetch

Usage

package main

import (
	"github.com/tinywasm/fetch"
)

func main() {
	// Simple GET request using relative path (auto-detects origin in WASM)
	fetch.Get("/data").
		Send(func(resp *fetch.Response, err error) {
			if err != nil {
				println("Error:", err.Error())
				return
			}
			println("Status:", resp.Status)
			println("Body:", resp.Text())
		})

	// POST request with JSON body using custom BaseURL
	body := []byte(`{"name":"Alice"}`)
	fetch.Post("/users").
		BaseURL("https://api.example.com").
		ContentTypeJSON().
		Body(body).
		Timeout(5000).
		Send(func(resp *fetch.Response, err error) {
			if err != nil {
				return
			}
			println("Created:", resp.Text())
		})
}

Documentation

• Base URL & Endpoint Resolution - How URLs are resolved automatically
• HTTP Headers - How to set and retrieve headers
• CORS Troubleshooting - Common issues in WASM environments

Content-Type Helpers

The following declarative methods are available on Request:

• ContentTypeJSON() -> application/json
• ContentTypeBinary() -> application/octet-stream
• ContentTypeForm() -> application/x-www-form-urlencoded
• ContentTypeText() -> text/plain
• ContentTypeHTML() -> text/html

Global Handler (Dispatch)

For fire-and-forget requests or centralized error handling:

func main() {
	// Set a global handler
	fetch.SetHandler(func(resp *fetch.Response) {
		if resp.Status >= 400 {
			println("Request to", resp.RequestURL, "failed with", resp.Status)
		}
	})

	// Fire and forget
	fetch.Post("/analytics").
		ContentTypeText().
		Body([]byte("event=click")).
		Dispatch()
}