### Initialize JWT Authentication and Generate Sample Token

Source: https://github.com/go-chi/jwtauth/blob/master/README.md

Initializes a new JWTAuth instance with a specific algorithm, secret, and nil options. It then generates and prints a sample JWT token with custom claims for debugging or demonstration purposes.

```go
package main

import (
	"fmt"
	"net/http"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/jwtauth/v5"
)

var tokenAuth *jwtauth.JWTAuth

func init() {
	tokenAuth = jwtauth.New("HS256", []byte("secret"), nil)

	// For debugging/example purposes, we generate and print
	// a sample jwt token with claims `user_id:123` here:
	_, tokenString, _ := tokenAuth.Encode(map[string]interface{}{"user_id": 123})
	fmt.Printf("DEBUG: a sample jwt is %s\n\n", tokenString)
}

func main() {
	addr := ":3333"
	fmt.Printf("Starting server on %v\n", addr)
	http.ListenAndServe(addr, router())
}

func router() http.Handler {
	r := chi.NewRouter()

	// Protected routes
	r.Group(func(r chi.Router) {
		// Seek, verify and validate JWT tokens
		r.Use(jwtauth.Verifier(tokenAuth))

		// Handle valid / invalid tokens. In this example, we use
		// the provided authenticator middleware, but you can write your
		// own very easily, look at the Authenticator method in jwtauth.go
		// and tweak it, its not scary.
		r.Use(jwtauth.Authenticator(tokenAuth))

		r.Get("/admin", func(w http.ResponseWriter, r *http.Request) {
			_, claims, _ := jwtauth.FromContext(r.Context())
			w.Write([]byte(fmt.Sprintf("protected area. hi %v", claims["user_id"])))
		})
	})

	// Public routes
	r.Group(func(r chi.Router) {
		r.Get("/", func(w http.ResponseWriter, r *http.Request) {
			w.Write([]byte("welcome anonymous"))
		})
	})

	return r
}

```

--------------------------------

### Generate JWT Token using jwtutil CLI

Source: https://github.com/go-chi/jwtauth/blob/master/README.md

Demonstrates how to generate a JWT token using the `jwtutil` command-line tool. This is useful for creating tokens with specific secrets and claims for testing or utility purposes.

```bash
go install github.com/goware/jwtutil

Usage: jwtutil -secret=secret -encode -claims='{"user_id":111}'

Output: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoxMTF9._cLJn0xFS0Mdr_4L_8XF8-8tv7bHyOQJXyWaNsSqlEs
```

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