Go echo and templ context passing middleware for csrf borrowed from https://jeffcaldwell.is/blog/using-echo-context-with-templ-components

custommiddleware.go

package custommiddleware

import (
	"context"

	"github.com/labstack/echo/v4"
)

// extend echo.Context
type contextValue struct {
	echo.Context
}

func (c contextValue) Get(key string) interface{} {
	// grab value from echo.Context
	val := c.Context.Get(key)
	// if it's not nil, return it
	if val != nil {
		return val
	}
	// otherwise, return Request.Context
	return c.Request().Context().Value(key)
}

func (c contextValue) Set(key string, val interface{}) {
	// we're replacing the whole Request in echo.Context
	// with a copied request that has the updated context value
	c.SetRequest(
		c.Request().WithContext(
			context.WithValue(c.Request().Context(), key, val),
		),
	)
}

func ContextValueMiddleware(next echo.HandlerFunc) echo.HandlerFunc {
	// this is just an echo.HandlerFunc
	return func(c echo.Context) error {
		// instead of passing next(c) as you usually would,
		// you return it with the extended version
		return next(contextValue{c})
	}
}

main.go

package main

func main() {
  e := echo.New()
  // before any other middleware
  e.Use(custommiddleware.ContextValueMiddleware)
	e.Use(middleware.CSRFWithConfig(middleware.CSRFConfig{
		Skipper:        middleware.DefaultSkipper,
		TokenLength:    32,
		ContextKey:     "csrf",
		CookieName:     "_csrf",
		CookieMaxAge:   86400,
		CookieSameSite: http.SameSiteNoneMode,
		CookieHTTPOnly: true,
		CookieSecure:   PROD,
		TokenLookup:    "form:csrf",
		CookiePath:     "/",
	}))
  // ...
}

myview.templ

func getCSRF(c context.Context) string {
	csrfToken := c.Value("csrf")
	if csrfToken != nil {
		return csrfToken.(string)
	}
	return ""
}

templ CSRF() {
	<input type="hidden" name="csrf" value={ getCSRF(ctx) }/>
}

// use by doing @CSRF() in any view