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🚀 App

Routing​

Route Handlers​

Registers a route bound to a specific HTTP method.

Signatures
// HTTP methods
func (app *App) Get(path string, handler Handler, handlers ...Handler) Router
func (app *App) Head(path string, handler Handler, handlers ...Handler) Router
func (app *App) Post(path string, handler Handler, handlers ...Handler) Router
func (app *App) Put(path string, handler Handler, handlers ...Handler) Router
func (app *App) Delete(path string, handler Handler, handlers ...Handler) Router
func (app *App) Connect(path string, handler Handler, handlers ...Handler) Router
func (app *App) Options(path string, handler Handler, handlers ...Handler) Router
func (app *App) Trace(path string, handler Handler, handlers ...Handler) Router
func (app *App) Patch(path string, handler Handler, handlers ...Handler) Router

// Add allows you to specify a method as value
func (app *App) Add(method, path string, handler Handler, handlers ...Handler) Router

// All will register the route on all HTTP methods
// Almost the same as app.Use but not bound to prefixes
func (app *App) All(path string, handler Handler, handlers ...Handler) Router
Examples
// Simple GET handler
app.Get("/api/list", func(c fiber.Ctx) error {
    return c.SendString("I'm a GET request!")
})

// Simple POST handler
app.Post("/api/register", func(c fiber.Ctx) error {
    return c.SendString("I'm a POST request!")
})
Use

Can be used for middleware packages and prefix catchers. These routes will only match the beginning of each path i.e. /john will match /john/doe, /johnnnnn etc

Signature
func (app *App) Use(args ...any) Router

// Different usage variations
func (app *App) Use(handler Handler, handlers ...Handler) Router
func (app *App) Use(path string, handler Handler, handlers ...Handler) Router
func (app *App) Use(paths []string, handler Handler, handlers ...Handler) Router
func (app *App) Use(path string, app *App) Router
Examples
// Match any request
app.Use(func(c fiber.Ctx) error {
    return c.Next()
})

// Match request starting with /api
app.Use("/api", func(c fiber.Ctx) error {
    return c.Next()
})

// Match requests starting with /api or /home (multiple-prefix support)
app.Use([]string{"/api", "/home"}, func(c fiber.Ctx) error {
    return c.Next()
})

// Attach multiple handlers 
app.Use("/api", func(c fiber.Ctx) error {
    c.Set("X-Custom-Header", random.String(32))
    return c.Next()
}, func(c fiber.Ctx) error {
    return c.Next()
})

// Mount a sub-app
app.Use("/api", api)

Mounting​

You can mount a Fiber instance using the app.Use method, similar to Express.

Example
package main

import (
    "log"

    "github.com/gofiber/fiber/v3"
)

func main() {
    app := fiber.New()
    micro := fiber.New()
    
    // Mount the micro app on the "/john" route
    app.Use("/john", micro) // GET /john/doe -> 200 OK
    
    micro.Get("/doe", func(c fiber.Ctx) error {
        return c.SendStatus(fiber.StatusOK)
    })
    
    log.Fatal(app.Listen(":3000"))
}

MountPath​

The MountPath property contains one or more path patterns on which a sub-app was mounted.

Signature
func (app *App) MountPath() string
Example
package main

import (
    "fmt"

    "github.com/gofiber/fiber/v3"
)

func main() {
    app := fiber.New()
    one := fiber.New()
    two := fiber.New()
    three := fiber.New()

    two.Use("/three", three)
    one.Use("/two", two)
    app.Use("/one", one)
    
    fmt.Println("Mount paths:")
    fmt.Println("one.MountPath():", one.MountPath())       // "/one"
    fmt.Println("two.MountPath():", two.MountPath())       // "/one/two"
    fmt.Println("three.MountPath():", three.MountPath())   // "/one/two/three"
    fmt.Println("app.MountPath():", app.MountPath())       // ""
}
caution

Mounting order is important for MountPath. To get mount paths properly, you should start mounting from the deepest app.

Group​

You can group routes by creating a *Group struct.

Signature
func (app *App) Group(prefix string, handlers ...Handler) Router
Example
package main

import (
    "log"

    "github.com/gofiber/fiber/v3"
)

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

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

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

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

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

func handler(c fiber.Ctx) error {
    return c.SendString("Handler response")
}

Route​

Returns an instance of a single route, which you can then use to handle HTTP verbs with optional middleware.

Similar to Express.

Signature
func (app *App) Route(path string) Register
Click here to see the Register interface
type Register interface {
    All(handler Handler, handlers ...Handler) Register
    Get(handler Handler, handlers ...Handler) Register
    Head(handler Handler, handlers ...Handler) Register
    Post(handler Handler, handlers ...Handler) Register
    Put(handler Handler, handlers ...Handler) Register
    Delete(handler Handler, handlers ...Handler) Register
    Connect(handler Handler, handlers ...Handler) Register
    Options(handler Handler, handlers ...Handler) Register
    Trace(handler Handler, handlers ...Handler) Register
    Patch(handler Handler, handlers ...Handler) Register

    Add(methods []string, handler Handler, handlers ...Handler) Register

    Route(path string) Register
}
Example
package main

import (
    "log"

    "github.com/gofiber/fiber/v3"
)

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

    // Use `Route` as a chainable route declaration method
    app.Route("/test").Get(func(c fiber.Ctx) error {
        return c.SendString("GET /test")
    })

    app.Route("/events").All(func(c fiber.Ctx) error {
        // Runs for all HTTP verbs first
        // Think of it as route-specific middleware!
    }).
    Get(func(c fiber.Ctx) error {
        return c.SendString("GET /events")
    }).
    Post(func(c fiber.Ctx) error {
        // Maybe add a new event...
        return c.SendString("POST /events")
    })

    // Combine multiple routes
    app.Route("/v2").Route("/user").Get(func(c fiber.Ctx) error {
        return c.SendString("GET /v2/user")
    })

    // Use multiple methods
    app.Route("/api").Get(func(c fiber.Ctx) error {
        return c.SendString("GET /api")
    }).Post(func(c fiber.Ctx) error {
        return c.SendString("POST /api")
    })

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

HandlersCount​

This method returns the number of registered handlers.

Signature
func (app *App) HandlersCount() uint32

Stack​

This method returns the original router stack.

Signature
func (app *App) Stack() [][]*Route
Example
package main

import (
    "encoding/json"
    "log"

    "github.com/gofiber/fiber/v3"
)

var handler = func(c fiber.Ctx) error { return nil }

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

    app.Get("/john/:age", handler)
    app.Post("/register", handler)

    data, _ := json.MarshalIndent(app.Stack(), "", "  ")
    fmt.Println(string(data))

    log.Fatal(app.Listen(":3000"))
}
Click here to see the result
[
  [
    {
      "method": "GET",
      "path": "/john/:age",
      "params": [
        "age"
      ]
    }
  ],
  [
    {
      "method": "HEAD",
      "path": "/john/:age",
      "params": [
        "age"
      ]
    }
  ],
  [
    {
      "method": "POST",
      "path": "/register",
      "params": null
    }
  ]
]

Name​

This method assigns the name to the latest created route.

Signature
func (app *App) Name(name string) Router
Example
package main

import (
    "encoding/json"
    "fmt"
    "log"

    "github.com/gofiber/fiber/v3"
)

func main() {
    var handler = func(c fiber.Ctx) error { return nil }

    app := fiber.New()

    app.Get("/", handler)
    app.Name("index")
    app.Get("/doe", handler).Name("home")
    app.Trace("/tracer", handler).Name("tracert")
    app.Delete("/delete", handler).Name("delete")

    a := app.Group("/a")
    a.Name("fd.")

    a.Get("/test", handler).Name("test")

    data, _ := json.MarshalIndent(app.Stack(), "", "  ")
    fmt.Println(string(data))

    log.Fatal(app.Listen(":3000"))
}
Click here to see the result
[
  [
    {
      "method": "GET",
      "name": "index",
      "path": "/",
      "params": null
    },
    {
      "method": "GET",
      "name": "home",
      "path": "/doe",
      "params": null
    },
    {
      "method": "GET",
      "name": "fd.test",
      "path": "/a/test",
      "params": null
    }
  ],
  [
    {
      "method": "HEAD",
      "name": "",
      "path": "/",
      "params": null
    },
    {
      "method": "HEAD",
      "name": "",
      "path": "/doe",
      "params": null
    },
    {
      "method": "HEAD",
      "name": "",
      "path": "/a/test",
      "params": null
    }
  ],
  null,
  null,
  [
    {
      "method": "DELETE",
      "name": "delete",
      "path": "/delete",
      "params": null
    }
  ],
  null,
  null,
  [
    {
      "method": "TRACE",
      "name": "tracert",
      "path": "/tracer",
      "params": null
    }
  ],
  null
]

GetRoute​

This method retrieves a route by its name.

Signature
func (app *App) GetRoute(name string) Route
Example
package main

import (
    "encoding/json"
    "fmt"
    "log"

    "github.com/gofiber/fiber/v3"
)

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

    app.Get("/", handler).Name("index")
    
    route := app.GetRoute("index")

    data, _ := json.MarshalIndent(route, "", "  ")
    fmt.Println(string(data))

    log.Fatal(app.Listen(":3000"))
}
Click here to see the result
{
  "method": "GET",
  "name": "index",
  "path": "/",
  "params": null
}

GetRoutes​

This method retrieves all routes.

Signature
func (app *App) GetRoutes(filterUseOption ...bool) []Route

When filterUseOption is set to true, it filters out routes registered by middleware.

Example
package main

import (
    "encoding/json"
    "fmt"
    "log"

    "github.com/gofiber/fiber/v3"
)

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

    app.Post("/", func(c fiber.Ctx) error {
        return c.SendString("Hello, World!")
    }).Name("index")

    routes := app.GetRoutes(true)

    data, _ := json.MarshalIndent(routes, "", "  ")
    fmt.Println(string(data))

    log.Fatal(app.Listen(":3000"))
}
Click here to see the result
[
    {
        "method": "POST",
        "name": "index",
        "path": "/",
        "params": null
    }
]

Config​

Config returns the app config as a value (read-only).

Signature
func (app *App) Config() Config

Handler​

Handler returns the server handler that can be used to serve custom \*fasthttp.RequestCtx requests.

Signature
func (app *App) Handler() fasthttp.RequestHandler

ErrorHandler​

ErrorHandler executes the process defined for the application in case of errors. This is used in some cases in middlewares.

Signature
func (app *App) ErrorHandler(ctx Ctx, err error) error

NewCtxFunc​

NewCtxFunc allows you to customize the ctx struct as needed.

Signature
func (app *App) NewCtxFunc(function func(app *App) CustomCtx)
Example
package main

import (
    "fmt"

    "github.com/gofiber/fiber/v3"
)

type CustomCtx struct {
    fiber.DefaultCtx
}

// Custom method
func (c *CustomCtx) Params(key string, defaultValue ...string) string {
    return "prefix_" + c.DefaultCtx.Params(key)
}

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

    app.NewCtxFunc(func(app *fiber.App) fiber.CustomCtx {
        return &CustomCtx{
            DefaultCtx: *fiber.NewDefaultCtx(app),
        }
    })

    app.Get("/:id", func(c fiber.Ctx) error {
        // Use custom method - output: prefix_123
        return c.SendString(c.Params("id"))
    })

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

RegisterCustomBinder​

You can register custom binders to use with Bind().Custom("name"). They should be compatible with the CustomBinder interface.

Signature
func (app *App) RegisterCustomBinder(binder CustomBinder)
Example
package main

import (
    "log"

    "github.com/gofiber/fiber/v3"
    "gopkg.in/yaml.v2"
)

type User struct {
    Name string `yaml:"name"`
}

type customBinder struct{}

func (*customBinder) Name() string {
    return "custom"
}

func (*customBinder) MIMETypes() []string {
    return []string{"application/yaml"}
}

func (*customBinder) Parse(c fiber.Ctx, out any) error {
    // Parse YAML body
    return yaml.Unmarshal(c.Body(), out)
}

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

    // Register custom binder
    app.RegisterCustomBinder(&customBinder{})

    app.Post("/custom", func(c fiber.Ctx) error {
        var user User
        // Use Custom binder by name
        if err := c.Bind().Custom("custom", &user); err != nil {
            return err
        }
        return c.JSON(user)
    })

    app.Post("/normal", func(c fiber.Ctx) error {
        var user User
        // Custom binder is used by the MIME type
        if err := c.Bind().Body(&user); err != nil {
            return err
        }
        return c.JSON(user)
    })

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

RegisterCustomConstraint​

RegisterCustomConstraint allows you to register custom constraints.

Signature
func (app *App) RegisterCustomConstraint(constraint CustomConstraint)

See the Custom Constraint section for more information.

SetTLSHandler​

Use SetTLSHandler to set ClientHelloInfo when using TLS with a Listener.

Signature
func (app *App) SetTLSHandler(tlsHandler *TLSHandler)

Test​

Testing your application is done with the Test method. Use this method for creating _test.go files or when you need to debug your routing logic. The default timeout is 1s; to disable a timeout altogether, pass a TestConfig struct with Timeout: 0.

Signature
func (app *App) Test(req *http.Request, config ...TestConfig) (*http.Response, error)
Example
package main

import (
    "fmt"
    "io"
    "log"
    "net/http"
    "net/http/httptest"

    "github.com/gofiber/fiber/v3"
)

func main() {
    app := fiber.New()
    
    // Create route with GET method for test:
    app.Get("/", func(c fiber.Ctx) error {
        fmt.Println(c.BaseURL())              // => http://google.com
        fmt.Println(c.Get("X-Custom-Header")) // => hi
        return c.SendString("hello, World!")
    })

    // Create http.Request
    req := httptest.NewRequest("GET", "http://google.com", nil)
    req.Header.Set("X-Custom-Header", "hi")

    // Perform the test
    resp, _ := app.Test(req)

    // Do something with the results:
    if resp.StatusCode == fiber.StatusOK {
        body, _ := io.ReadAll(resp.Body)
        fmt.Println(string(body)) // => hello, World!
    }
}

If not provided, TestConfig is set to the following defaults:

Default TestConfig
config := fiber.TestConfig{
  Timeout:      time.Second(),
  FailOnTimeout: true,
}
caution

This is not the same as supplying an empty TestConfig{} to `app.Test(), but rather be the equivalent of supplying:

Empty TestConfig
cfg := fiber.TestConfig{
  Timeout:      0,
  FailOnTimeout: false,
}

This would make a Test that has no timeout.

Hooks​

Hooks is a method to return the hooks property.

Signature
func (app *App) Hooks() *Hooks

RebuildTree​

The RebuildTree method is designed to rebuild the route tree and enable dynamic route registration. It returns a pointer to the App instance.

Signature
func (app *App) RebuildTree() *App

Note: Use this method with caution. It is not thread-safe and calling it can be very performance-intensive, so it should be used sparingly and only in development mode. Avoid using it concurrently.

Example Usage​

Here’s an example of how to define and register routes dynamically:

Example
package main

import (
    "log"

    "github.com/gofiber/fiber/v3"
)

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

    app.Get("/define", func(c fiber.Ctx) error {
        // Define a new route dynamically
        app.Get("/dynamically-defined", func(c fiber.Ctx) error {
            return c.SendStatus(fiber.StatusOK)
        })

        // Rebuild the route tree to register the new route
        app.RebuildTree()

        return c.SendStatus(fiber.StatusOK)
    })

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

In this example, a new route is defined and then RebuildTree() is called to ensure the new route is registered and available.