🎭 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"))
}