vel

vel

A type-safe Go HTTP framework with automatic OpenAPI generation and client code generation.

Features

• Type-safe handlers using Go generics for compile-time safety
• Automatic OpenAPI 3.0 generation from your handler implementations
• Client code generation for Go and TypeScript
• Full net/http compatibility - no custom abstractions
• Code-first approach - API specs generated from implementation, not documentation
• Minimal dependencies - built on Go standard library

Quick Start

package main

import (
	"context"
	"net/http"

	"github.com/dennypenta/vel"
)

type HelloRequest struct {
	Name string `json:"name"`
}

type HelloResponse struct {
	Message string `json:"message"`
}

func HelloHandler(ctx context.Context, req HelloRequest) (HelloResponse, *vel.Error) {
	return HelloResponse{
		Message: "Hello, " + req.Name,
	}, nil
}

func main() {
	router := vel.NewRouter()
	vel.RegisterPost(router, "hello", HelloHandler)

	http.ListenAndServe(":8080", router.Mux())
}

Installation

go get github.com/dennypenta/vel

Documentation

https://vel-8u3w.onrender.com

Development

• Test: go test -v ./...
• Format: goimports -w .

Design Philosophy

• Opinionated: No path parameters, explicit types required
• Simple: Leverages Go's type system for safety
• Compatible: Full net/http compatibility maintained
• Generated: OpenAPI specs and clients generated from code

Backlog

• SSE code gen for clients and OpenAPI
• Error codes code gen, from yaml generate the server constants and its mapping to http status, from the same file OpenAPI can be enriched to include the error codes
• Extend possible Error types, to support not only the build-in one, but others
• Custom clients templates to generate clients as you wish