echo/website/content/guide/routing.md

title	menu
Routing	main parent weight guide 3

Echo's router is [fast, optimized]({{< relref "index.md#performance">}}) and flexible. It's based on radix tree data structure which makes route lookup really fast. Router leverages sync pool to reuse memory and achieve zero dynamic memory allocation with no GC overhead.

Routes can be registered by specifying HTTP method, path and a handler. For example, code below registers a route for method GET, path /hello and a handler which sends Hello! HTTP response.

e.Get("/hello", func(c *echo.Context) error {
	return c.String(http.StatusOK, "Hello!")
})

Echo's default handler is func(*echo.Context) error where echo.Context primarily holds HTTP request and response objects. Echo also has a support for other types of handlers.

Match-any

Matches zero or more characters in the path. For example, pattern /users/* will match:

• /users/
• /users/1
• /users/1/files/1
• /users/anything...

Path matching order

• Static
• Param
• Match any

Example

e.Get("/users/:id", func(c *echo.Context) error {
	return c.String(http.StatusOK, "/users/:id")
})

e.Get("/users/new", func(c *echo.Context) error {
	return c.String(http.StatusOK, "/users/new")
})

e.Get("/users/1/files/*", func(c *echo.Context) error {
	return c.String(http.StatusOK, "/users/1/files/*")
})

Above routes would resolve in the following order:

• /users/new
• /users/:id
• /users/1/files/*

Routes can be written in any order.

Group

Echo.Group(prefix string, m ...Middleware) *Group

Routes with common prefix can be grouped to define a new sub-router with optional middleware. If middleware is passed to the function, it overrides parent middleware

• helpful if you want a completely new middleware stack for the group. To add middleware later you can use Group.Use(m ...Middleware). Groups can also be nested.

In the code below, we create an admin group which requires basic HTTP authentication for routes /admin/*.

echo.Group("/admin")
e.Use(mw.BasicAuth(func(usr, pwd string) bool {
	if usr == "joe" && pwd == "secret" {
		return true
	}
	return false
}))

URI building

Echo.URI can be used to generate URI for any handler with specified path parameters. It's helpful to centralize all your URI patterns which ease in refactoring your application.

e.URI(h, 1) will generate /users/1 for the route registered below

// Handler
h := func(c *echo.Context) error {
	return c.String(http.StatusOK, "OK")
}

// Route
e.Get("/users/:id", h)