🎭 Grouping - Fiber

:::info Grouping works like Express.js. Groups are virtual; routes are flattened with the group's prefix and executed in declaration order, mirroring Express.js. :::

Paths

Groups can use path prefixes to organize related routes.

func main() {
    app := fiber.New()

    api := app.Group("/api", middleware) // /api

    v1 := api.Group("/v1", middleware)   // /api/v1
    v1.Get("/list", handler)             // /api/v1/list
    v1.Get("/user", handler)             // /api/v1/user

    v2 := api.Group("/v2", middleware)   // /api/v2
    v2.Get("/list", handler)             // /api/v2/list
    v2.Get("/user", handler)             // /api/v2/user

    log.Fatal(app.Listen(":3000"))
}

:::note Group prefixes follow the same slash-boundary rule as app.Use. A prefix must either match the full path or stop at a /, so /api applies to /api and /api/v1 but not /apiv1. Parameter markers (for example :id, :id?, *, and +) are processed before checking the boundary. :::

Groups can also include an optional handler.

func main() {
    app := fiber.New()

    api := app.Group("/api")      // /api

    v1 := api.Group("/v1")        // /api/v1
    v1.Get("/list", handler)      // /api/v1/list
    v1.Get("/user", handler)      // /api/v1/user

    v2 := api.Group("/v2")        // /api/v2
    v2.Get("/list", handler)      // /api/v2/list
    v2.Get("/user", handler)      // /api/v2/user

    log.Fatal(app.Listen(":3000"))
}

:::caution Accessing /api, /v1, or /v2 directly returns a 404, so add error handlers as needed. :::

Group Handlers

Group handlers can act as routing paths but must call Next to continue the flow.

func main() {
    app := fiber.New()

    handler := func(c fiber.Ctx) error {
        return c.SendStatus(fiber.StatusOK)
    }
    api := app.Group("/api") // /api

    v1 := api.Group("/v1", func(c fiber.Ctx) error { // middleware for /api/v1
        c.Set("Version", "v1")
        return c.Next()
    })
    v1.Get("/list", handler) // /api/v1/list
    v1.Get("/user", handler) // /api/v1/user

    log.Fatal(app.Listen(":3000"))
}

Route

Route groups routes under a common prefix declared inside a single callback, with an optional name prefix. It is shorthand for nesting with Group.

app.Route("/api/v1", func(r fiber.Router) {
    r.Get("/users", handler).Name("users")   // /api/v1/users  (name: v1.users)
    r.Post("/users", handler).Name("create") // /api/v1/users  (name: v1.create)
}, "v1.")

RouteChain

When several HTTP methods share the same path, RouteChain lets you declare the path once and chain the verb handlers. An All in the chain runs before the verb handlers on that path, acting as route-specific middleware.

app.RouteChain("/events").
    All(func(c fiber.Ctx) error { return c.Next() }). // route-local middleware
    Get(func(c fiber.Ctx) error { return c.SendString("GET /events") }).
    Post(func(c fiber.Ctx) error { return c.SendString("POST /events") })

:::note Within a chain, All registers prefix-matched middleware (like app.Use), not the exact-path App.All, so it also runs for sub-paths of the chain path. :::