GOMODULES
/
fiber
mirror of https://github.com/gofiber/fiber.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
fiber/docs/api/ctx.md

56 KiB
Raw Blame History

id title description sidebar_position
ctx 🧠 Ctx The Ctx interface represents the Context which hold the HTTP request and response. It has methods for the request query string, parameters, body, HTTP headers, and so on. 3

Accepts

Checks, if the specified extensions or content types are acceptable.

:::info Based on the request’s Accept HTTP header. :::

func (c Ctx) Accepts(offers ...string)          string
func (c Ctx) AcceptsCharsets(offers ...string)  string
func (c Ctx) AcceptsEncodings(offers ...string) string
func (c Ctx) AcceptsLanguages(offers ...string) string

// Accept: text/html, application/json; q=0.8, text/plain; q=0.5; charset="utf-8"

app.Get("/", func(c fiber.Ctx) error {
  c.Accepts("html")             // "html"
  c.Accepts("text/html")        // "text/html"
  c.Accepts("json", "text")     // "json"
  c.Accepts("application/json") // "application/json"
  c.Accepts("text/plain", "application/json") // "application/json", due to quality
  c.Accepts("image/png")        // ""
  c.Accepts("png")              // ""
  // ...
})

// Accept: text/html, text/*, application/json, */*; q=0

app.Get("/", func(c fiber.Ctx) error {
  c.Accepts("text/plain", "application/json") // "application/json", due to specificity
  c.Accepts("application/json", "text/html") // "text/html", due to first match
  c.Accepts("image/png")        // "", due to */* without q factor 0 is Not Acceptable
  // ...
})

Media-Type parameters are supported.

// Accept: text/plain, application/json; version=1; foo=bar

app.Get("/", func(c fiber.Ctx) error {
  // Extra parameters in the accept are ignored
  c.Accepts("text/plain;format=flowed") // "text/plain;format=flowed"
  
  // An offer must contain all parameters present in the Accept type
  c.Accepts("application/json") // ""

  // Parameter order and capitalization does not matter. Quotes on values are stripped.
  c.Accepts(`application/json;foo="bar";VERSION=1`) // "application/json;foo="bar";VERSION=1"
})

// Accept: text/plain;format=flowed;q=0.9, text/plain
// i.e., "I prefer text/plain;format=flowed less than other forms of text/plain"
app.Get("/", func(c fiber.Ctx) error {
  // Beware: the order in which offers are listed matters.
  // Although the client specified they prefer not to receive format=flowed,
  // the text/plain Accept matches with "text/plain;format=flowed" first, so it is returned.
  c.Accepts("text/plain;format=flowed", "text/plain") // "text/plain;format=flowed"

  // Here, things behave as expected:
  c.Accepts("text/plain", "text/plain;format=flowed") // "text/plain"
})

Fiber provides similar functions for the other accept headers.

// Accept-Charset: utf-8, iso-8859-1;q=0.2
// Accept-Encoding: gzip, compress;q=0.2
// Accept-Language: en;q=0.8, nl, ru

app.Get("/", func(c fiber.Ctx) error {
  c.AcceptsCharsets("utf-16", "iso-8859-1")
  // "iso-8859-1"

  c.AcceptsEncodings("compress", "br")
  // "compress"

  c.AcceptsLanguages("pt", "nl", "ru")
  // "nl"
  // ...
})

App

Returns the *App reference so you could easily access all application settings.

func (c Ctx) App() *App

app.Get("/stack", func(c fiber.Ctx) error {
  return c.JSON(c.App().Stack())
})

Append

Appends the specified value to the HTTP response header field.

:::caution If the header is not already set, it creates the header with the specified value. :::

func (c Ctx) Append(field string, values ...string)

app.Get("/", func(c fiber.Ctx) error {
  c.Append("Link", "http://google.com", "http://localhost")
  // => Link: http://localhost, http://google.com

  c.Append("Link", "Test")
  // => Link: http://localhost, http://google.com, Test

  // ...
})

Attachment

Sets the HTTP response Content-Disposition header field to attachment.

func (c Ctx) Attachment(filename ...string)

app.Get("/", func(c fiber.Ctx) error {
  c.Attachment()
  // => Content-Disposition: attachment

  c.Attachment("./upload/images/logo.png")
  // => Content-Disposition: attachment; filename="logo.png"
  // => Content-Type: image/png

  // ...
})

AutoFormat

Performs content-negotiation on the Accept HTTP header. It uses Accepts to select a proper format. The supported content types are text/html, text/plain, application/json, and application/xml. For more flexible content negotiation, use Format.

:::info If the header is not specified or there is no proper format, text/plain is used. :::

func (c Ctx) AutoFormat(body any) error

app.Get("/", func(c fiber.Ctx) error {
  // Accept: text/plain
  c.AutoFormat("Hello, World!")
  // => Hello, World!

  // Accept: text/html
  c.AutoFormat("Hello, World!")
  // => <p>Hello, World!</p>

  type User struct {
    Name string
  }
  user := User{"John Doe"}

  // Accept: application/json
  c.AutoFormat(user)
  // => {"Name":"John Doe"}

  // Accept: application/xml
  c.AutoFormat(user)
  // => <User><Name>John Doe</Name></User>
  // ..
})

BaseURL

Returns the base URL **protocol** + **host** as a string.

func (c Ctx) BaseURL() string

// GET https://example.com/page#chapter-1

app.Get("/", func(c fiber.Ctx) error {
  c.BaseURL() // https://example.com
  // ...
})

Bind

Bind is a method that support supports bindings for the request/response body, query parameters, URL parameters, cookies and much more. It returns a pointer to the Bind struct which contains all the methods to bind the request/response data.

For detailed information check the Bind documentation.

func (c Ctx) Bind() *Bind

app.Post("/", func(c fiber.Ctx) error {
  user := new(User)
  // Bind the request body to a struct:
  return c.Bind().Body(user)
})

Body

As per the header Content-Encoding, this method will try to perform a file decompression from the body bytes. In case no Content-Encoding header is sent, it will perform as BodyRaw.

func (c Ctx) Body() []byte

// echo 'user=john' | gzip | curl -v -i --data-binary @- -H "Content-Encoding: gzip" http://localhost:8080

app.Post("/", func(c fiber.Ctx) error {
  // Decompress body from POST request based on the Content-Encoding and return the raw content:
  return c.Send(c.Body()) // []byte("user=john")
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

BodyRaw

Returns the raw request body.

func (c Ctx) BodyRaw() []byte

// curl -X POST http://localhost:8080 -d user=john

app.Post("/", func(c fiber.Ctx) error {
  // Get raw body from POST request:
  return c.Send(c.BodyRaw()) // []byte("user=john")
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

ClearCookie

Expire a client cookie _or all cookies if left empty_

func (c Ctx) ClearCookie(key ...string)

app.Get("/", func(c fiber.Ctx) error {
  // Clears all cookies:
  c.ClearCookie()

  // Expire specific cookie by name:
  c.ClearCookie("user")

  // Expire multiple cookies by names:
  c.ClearCookie("token", "session", "track_id", "version")
  // ...
})

:::caution Web browsers and other compliant clients will only clear the cookie if the given options are identical to those when creating the cookie, excluding expires and maxAge. ClearCookie will not set these values for you - a technique similar to the one shown below should be used to ensure your cookie is deleted. :::

app.Get("/set", func(c fiber.Ctx) error {
    c.Cookie(&fiber.Cookie{
        Name:     "token",
        Value:    "randomvalue",
        Expires:  time.Now().Add(24 * time.Hour),
        HTTPOnly: true,
        SameSite: "lax",
    })

    // ...
})

app.Get("/delete", func(c fiber.Ctx) error {
    c.Cookie(&fiber.Cookie{
        Name:     "token",
        // Set expiry date to the past
        Expires:  time.Now().Add(-(time.Hour * 2)),
        HTTPOnly: true,
        SameSite: "lax",
    })

    // ...
})

ClientHelloInfo

ClientHelloInfo contains information from a ClientHello message in order to guide application logic in the GetCertificate and GetConfigForClient callbacks. You can refer to the ClientHelloInfo struct documentation for more information on the returned struct.

func (c Ctx) ClientHelloInfo() *tls.ClientHelloInfo

// GET http://example.com/hello
app.Get("/hello", func(c fiber.Ctx) error {
  chi := c.ClientHelloInfo()
  // ...
})

Context

Returns *fasthttp.RequestCtx that is compatible with the context.Context interface that requires a deadline, a cancellation signal, and other values across API boundaries.

func (c Ctx) Context() *fasthttp.RequestCtx

:::info Please read the Fasthttp Documentation for more information. :::

Cookie

Set cookie

func (c Ctx) Cookie(cookie *Cookie)

type Cookie struct {
    Name        string    `json:"name"`         // The name of the cookie
    Value       string    `json:"value"`        // The value of the cookie
    Path        string    `json:"path"`         // Specifies a URL path which is allowed to receive the cookie
    Domain      string    `json:"domain"`       // Specifies the domain which is allowed to receive the cookie
    MaxAge      int       `json:"max_age"`      // The maximum age (in seconds) of the cookie
    Expires     time.Time `json:"expires"`      // The expiration date of the cookie
    Secure      bool      `json:"secure"`       // Indicates that the cookie should only be transmitted over a secure HTTPS connection
    HTTPOnly    bool      `json:"http_only"`    // Indicates that the cookie is accessible only through the HTTP protocol
    SameSite    string    `json:"same_site"`    // Controls whether or not a cookie is sent with cross-site requests
    Partitioned bool      `json:"partitioned"`  // Indicates if the cookie is stored in a partitioned cookie jar
    SessionOnly bool      `json:"session_only"` // Indicates if the cookie is a session-only cookie
}

app.Get("/", func(c fiber.Ctx) error {
  // Create cookie
  cookie := new(fiber.Cookie)
  cookie.Name = "john"
  cookie.Value = "doe"
  cookie.Expires = time.Now().Add(24 * time.Hour)

  // Set cookie
  c.Cookie(cookie)
  // ...
})

:::info

Partitioned cookies allow partitioning the cookie jar by top-level site, enhancing user privacy by preventing cookies from being shared across different sites. This feature is particularly useful in scenarios where a user interacts with embedded third-party services that should not have access to the main site's cookies. You can check out CHIPS for more information.

:::

app.Get("/", func(c fiber.Ctx) error {
  // Create a new partitioned cookie
  cookie := new(fiber.Cookie)
  cookie.Name = "user_session"
  cookie.Value = "abc123"
  cookie.Partitioned = true  // This cookie will be stored in a separate jar when it's embeded into another website

  // Set the cookie in the response
  c.Cookie(cookie)
  return c.SendString("Partitioned cookie set")
})

Cookies

Get cookie value by key, you could pass an optional default value that will be returned if the cookie key does not exist.

func (c Ctx) Cookies(key string, defaultValue ...string) string

app.Get("/", func(c fiber.Ctx) error {
  // Get cookie by key:
  c.Cookies("name")         // "john"
  c.Cookies("empty", "doe") // "doe"
  // ...
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

Download

Transfers the file from path as an attachment.

Typically, browsers will prompt the user to download. By default, the Content-Disposition header filename= parameter is the file path _this typically appears in the browser dialog_.

Override this default with the filename parameter.

func (c Ctx) Download(file string, filename ...string) error

app.Get("/", func(c fiber.Ctx) error {
  return c.Download("./files/report-12345.pdf");
  // => Download report-12345.pdf

  return c.Download("./files/report-12345.pdf", "report.pdf");
  // => Download report.pdf
})

Format

Performs content-negotiation on the Accept HTTP header. It uses Accepts to select a proper format from the supplied offers. A default handler can be provided by setting the MediaType to "default". If no offers match and no default is provided, a 406 (Not Acceptable) response is sent. The Content-Type is automatically set when a handler is selected.

:::info If the Accept header is not specified, the first handler will be used. :::

func (c Ctx) Format(handlers ...ResFmt) error

// Accept: application/json => {"command":"eat","subject":"fruit"}
// Accept: text/plain => Eat Fruit!
// Accept: application/xml => Not Acceptable
app.Get("/no-default", func(c fiber.Ctx) error {
  return c.Format(
    fiber.ResFmt{"application/json", func(c fiber.Ctx) error {
      return c.JSON(fiber.Map{
        "command": "eat",
        "subject": "fruit",
      })
    }},
    fiber.ResFmt{"text/plain", func(c fiber.Ctx) error {
      return c.SendString("Eat Fruit!")
    }},
  )
})

// Accept: application/json => {"command":"eat","subject":"fruit"}
// Accept: text/plain => Eat Fruit!
// Accept: application/xml => Eat Fruit!
app.Get("/default", func(c fiber.Ctx) error {
  textHandler := func(c fiber.Ctx) error {
    return c.SendString("Eat Fruit!")
  }

  handlers := []fiber.ResFmt{
    {"application/json", func(c fiber.Ctx) error {
      return c.JSON(fiber.Map{
        "command": "eat",
        "subject": "fruit",
      })
    }},
    {"text/plain", textHandler},
    {"default", textHandler},
  }

  return c.Format(handlers...)
})

FormFile

MultipartForm files can be retrieved by name, the first file from the given key is returned.

func (c Ctx) FormFile(key string) (*multipart.FileHeader, error)

app.Post("/", func(c fiber.Ctx) error {
  // Get first file from form field "document":
  file, err := c.FormFile("document")

  // Save file to root directory:
  return c.SaveFile(file, fmt.Sprintf("./%s", file.Filename))
})

FormValue

Any form values can be retrieved by name, the first value from the given key is returned.

func (c Ctx) FormValue(key string, defaultValue ...string) string

app.Post("/", func(c fiber.Ctx) error {
  // Get first value from form field "name":
  c.FormValue("name")
  // => "john" or "" if not exist

  // ..
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

Fresh

When the response is still fresh in the client's cache true is returned, otherwise false is returned to indicate that the client cache is now stale and the full response should be sent.

When a client sends the Cache-Control: no-cache request header to indicate an end-to-end reload request, Fresh will return false to make handling these requests transparent.

Read more on https://expressjs.com/en/4x/api.html#req.fresh

func (c Ctx) Fresh() bool

Get

Returns the HTTP request header specified by the field.

:::tip The match is case-insensitive. :::

func (c Ctx) Get(key string, defaultValue ...string) string

app.Get("/", func(c fiber.Ctx) error {
  c.Get("Content-Type")       // "text/plain"
  c.Get("CoNtEnT-TypE")       // "text/plain"
  c.Get("something", "john")  // "john"
  // ..
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

GetReqHeaders

Returns the HTTP request headers as a map. Since a header can be set multiple times in a single request, the values of the map are slices of strings containing all the different values of the header.

func (c Ctx) GetReqHeaders() map[string][]string

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

GetRespHeader

Returns the HTTP response header specified by the field.

:::tip The match is case-insensitive. :::

func (c Ctx) GetRespHeader(key string, defaultValue ...string) string

app.Get("/", func(c fiber.Ctx) error {
  c.GetRespHeader("X-Request-Id")       // "8d7ad5e3-aaf3-450b-a241-2beb887efd54"
  c.GetRespHeader("Content-Type")       // "text/plain"
  c.GetRespHeader("something", "john")  // "john"
  // ..
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

GetRespHeaders

Returns the HTTP response headers as a map. Since a header can be set multiple times in a single request, the values of the map are slices of strings containing all the different values of the header.

func (c Ctx) GetRespHeaders() map[string][]string

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

GetRouteURL

Generates URLs to named routes, with parameters. URLs are relative, for example: "/user/1831"

func (c Ctx) GetRouteURL(routeName string, params Map) (string, error)

app.Get("/", func(c fiber.Ctx) error {
    return c.SendString("Home page")
}).Name("home")

app.Get("/user/:id", func(c fiber.Ctx) error {
    return c.SendString(c.Params("id"))
}).Name("user.show")

app.Get("/test", func(c fiber.Ctx) error {
    location, _ := c.GetRouteURL("user.show", fiber.Map{"id": 1})
    return c.SendString(location)
})

// /test returns "/user/1"

Host

Returns the host derived from the Host HTTP header.

In a network context, Host refers to the combination of a hostname and potentially a port number used for connecting, while Hostname refers specifically to the name assigned to a device on a network, excluding any port information.

func (c Ctx) Host() string

// GET http://google.com:8080/search

app.Get("/", func(c fiber.Ctx) error {
  c.Host() // "google.com:8080"
  c.Hostname() // "google.com"

  // ...
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

Hostname

Returns the hostname derived from the Host HTTP header.

func (c Ctx) Hostname() string

// GET http://google.com/search

app.Get("/", func(c fiber.Ctx) error {
  c.Hostname() // "google.com"

  // ...
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

IP

Returns the remote IP address of the request.

func (c Ctx) IP() string

app.Get("/", func(c fiber.Ctx) error {
  c.IP() // "127.0.0.1"

  // ...
})

When registering the proxy request header in the fiber app, the ip address of the header is returned (Fiber configuration)

app := fiber.New(fiber.Config{
  ProxyHeader: fiber.HeaderXForwardedFor,
})

IPs

Returns an array of IP addresses specified in the X-Forwarded-For request header.

func (c Ctx) IPs() []string

// X-Forwarded-For: proxy1, 127.0.0.1, proxy3

app.Get("/", func(c fiber.Ctx) error {
  c.IPs() // ["proxy1", "127.0.0.1", "proxy3"]

  // ...
})

:::caution Improper use of the X-Forwarded-For header can be a security risk. For details, see the Security and privacy concerns section. :::

Is

Returns the matching content type, if the incoming request’s Content-Type HTTP header field matches the MIME type specified by the type parameter.

:::info If the request has no body, it returns false. :::

func (c Ctx) Is(extension string) bool

// Content-Type: text/html; charset=utf-8

app.Get("/", func(c fiber.Ctx) error {
  c.Is("html")  // true
  c.Is(".html") // true
  c.Is("json")  // false

  // ...
})

IsFromLocal

Returns true if request came from localhost

func (c Ctx) IsFromLocal() bool {


app.Get("/", func(c fiber.Ctx) error {
  // If request came from localhost, return true else return false
  c.IsFromLocal()

  // ...
})

IsProxyTrusted

Checks trustworthiness of remote ip. If EnableTrustedProxyCheck false, it returns true IsProxyTrusted can check remote ip by proxy ranges and ip map.

func (c Ctx) IsProxyTrusted() bool


app := fiber.New(fiber.Config{
  // EnableTrustedProxyCheck enables the trusted proxy check
  EnableTrustedProxyCheck: true,
  // TrustedProxies is a list of trusted proxy IP addresses
  TrustedProxies: []string{"0.8.0.0", "0.8.0.1"},
})
        

app.Get("/", func(c fiber.Ctx) error {
  // If request came from trusted proxy, return true else return false
  c.IsProxyTrusted()

  // ...
})

JSON

Converts any interface or string to JSON using the encoding/json package.

:::info JSON also sets the content header to the ctype parameter. If no ctype is passed in, the header is set to application/json. :::

func (c Ctx) JSON(data any, ctype ...string) error

type SomeStruct struct {
  Name string
  Age  uint8
}

app.Get("/json", func(c fiber.Ctx) error {
  // Create data struct:
  data := SomeStruct{
    Name: "Grame",
    Age:  20,
  }

  return c.JSON(data)
  // => Content-Type: application/json
  // => "{"Name": "Grame", "Age": 20}"

  return c.JSON(fiber.Map{
    "name": "Grame",
    "age": 20,
  })
  // => Content-Type: application/json
  // => "{"name": "Grame", "age": 20}"

  return c.JSON(fiber.Map{
    "type": "https://example.com/probs/out-of-credit",
    "title": "You do not have enough credit.",
    "status": 403,
    "detail": "Your current balance is 30, but that costs 50.",
    "instance": "/account/12345/msgs/abc",
  }, "application/problem+json")
  // => Content-Type: application/problem+json
  // => "{
  // =>     "type": "https://example.com/probs/out-of-credit",
  // =>     "title": "You do not have enough credit.",
  // =>     "status": 403,
  // =>     "detail": "Your current balance is 30, but that costs 50.",
  // =>     "instance": "/account/12345/msgs/abc",
  // => }"
})

JSONP

Sends a JSON response with JSONP support. This method is identical to JSON, except that it opts-in to JSONP callback support. By default, the callback name is simply callback.

Override this by passing a named string in the method.

func (c Ctx) JSONP(data any, callback ...string) error

type SomeStruct struct {
  name string
  age  uint8
}

app.Get("/", func(c fiber.Ctx) error {
  // Create data struct:
  data := SomeStruct{
    name: "Grame",
    age:  20,
  }

  return c.JSONP(data)
  // => callback({"name": "Grame", "age": 20})

  return c.JSONP(data, "customFunc")
  // => customFunc({"name": "Grame", "age": 20})
})

Links

Joins the links followed by the property to populate the response’s Link HTTP header field.

func (c Ctx) Links(link ...string)

app.Get("/", func(c fiber.Ctx) error {
  c.Links(
    "http://api.example.com/users?page=2", "next",
    "http://api.example.com/users?page=5", "last",
  )
  // Link: <http://api.example.com/users?page=2>; rel="next",
  //       <http://api.example.com/users?page=5>; rel="last"

  // ...
})

Locals

A method that stores variables scoped to the request and, therefore, are available only to the routes that match the request. The stored variables are removed after the request is handled. If any of the stored data implements the io.Closer interface, its Close method will be called before it's removed.

:::tip This is useful if you want to pass some specific data to the next middleware. Remember to perform type assertions when retrieving the data to ensure it is of the expected type. You can also use a non-exported type as a key to avoid collisions. :::

func (c Ctx) Locals(key any, value ...any) any


// keyType is an unexported type for keys defined in this package.
// This prevents collisions with keys defined in other packages.
type keyType int

// userKey is the key for user.User values in Contexts. It is
// unexported; clients use user.NewContext and user.FromContext
// instead of using this key directly.
var userKey keyType

app.Use(func(c fiber.Ctx) error {
  c.Locals(userKey, "admin") // Stores the string "admin" under a non-exported type key
  return c.Next()
})

app.Get("/admin", func(c fiber.Ctx) error {
  user, ok := c.Locals(userKey).(string) // Retrieves the data stored under the key and performs a type assertion
  if ok && user == "admin" {
    return c.Status(fiber.StatusOK).SendString("Welcome, admin!")
  }
  return c.SendStatus(fiber.StatusForbidden)
})

An alternative version of the Locals method that takes advantage of Go's generics feature is also available. This version allows for the manipulation and retrieval of local values within a request's context with a more specific data type.

func Locals[V any](c Ctx, key any, value ...V) V

app.Use(func(c Ctx) error {
  fiber.Locals[string](c, "john", "doe")
  fiber.Locals[int](c, "age", 18)
  fiber.Locals[bool](c, "isHuman", true)
  return c.Next()
})
app.Get("/test", func(c Ctx) error {
  fiber.Locals[string](c, "john")     // "doe"
  fiber.Locals[int](c, "age")         // 18
  fiber.Locals[bool](c, "isHuman")    // true
  return nil
})

Make sure to understand and correctly implement the Locals method in both its standard and generic form for better control over route-specific data within your application.

Location

Sets the response Location HTTP header to the specified path parameter.

func (c Ctx) Location(path string)

app.Post("/", func(c fiber.Ctx) error {
  c.Location("http://example.com")

  c.Location("/foo/bar")

  return nil
})

Method

Returns a string corresponding to the HTTP method of the request: GET, POST, PUT, and so on.
Optionally, you could override the method by passing a string.

func (c Ctx) Method(override ...string) string

app.Post("/", func(c fiber.Ctx) error {
  c.Method() // "POST"

  c.Method("GET")
  c.Method() // GET

  // ...
})

MultipartForm

To access multipart form entries, you can parse the binary with MultipartForm(). This returns a map[string][]string, so given a key, the value will be a string slice.

func (c Ctx) MultipartForm() (*multipart.Form, error)

app.Post("/", func(c fiber.Ctx) error {
  // Parse the multipart form:
  if form, err := c.MultipartForm(); err == nil {
    // => *multipart.Form

    if token := form.Value["token"]; len(token) > 0 {
      // Get key value:
      fmt.Println(token[0])
    }

    // Get all files from "documents" key:
    files := form.File["documents"]
    // => []*multipart.FileHeader

    // Loop through files:
    for _, file := range files {
      fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
      // => "tutorial.pdf" 360641 "application/pdf"

      // Save the files to disk:
      if err := c.SaveFile(file, fmt.Sprintf("./%s", file.Filename)); err != nil {
        return err
      }
    }
  }

  return err
})

Next

When Next is called, it executes the next method in the stack that matches the current route. You can pass an error struct within the method that will end the chaining and call the error handler.

func (c Ctx) Next() error

app.Get("/", func(c fiber.Ctx) error {
  fmt.Println("1st route!")
  return c.Next()
})

app.Get("*", func(c fiber.Ctx) error {
  fmt.Println("2nd route!")
  return c.Next()
})

app.Get("/", func(c fiber.Ctx) error {
  fmt.Println("3rd route!")
  return c.SendString("Hello, World!")
})

OriginalURL

Returns the original request URL.

func (c Ctx) OriginalURL() string

// GET http://example.com/search?q=something

app.Get("/", func(c fiber.Ctx) error {
  c.OriginalURL() // "/search?q=something"

  // ...
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

Params

Method can be used to get the route parameters, you could pass an optional default value that will be returned if the param key does not exist.

:::info Defaults to empty string `""`, if the param doesn't exist. :::

func (c Ctx) Params(key string, defaultValue ...string) string

// GET http://example.com/user/fenny
app.Get("/user/:name", func(c fiber.Ctx) error {
  c.Params("name") // "fenny"

  // ...
})

// GET http://example.com/user/fenny/123
app.Get("/user/*", func(c fiber.Ctx) error {
  c.Params("*")  // "fenny/123"
  c.Params("*1") // "fenny/123"

  // ...
})

Unnamed route parameters(*, +) can be fetched by the character and the counter in the route.

// ROUTE: /v1/*/shop/*
// GET:   /v1/brand/4/shop/blue/xs
c.Params("*1")  // "brand/4"
c.Params("*2")  // "blue/xs"

For reasons of downward compatibility, the first parameter segment for the parameter character can also be accessed without the counter.

app.Get("/v1/*/shop/*", func(c fiber.Ctx) error {
  c.Params("*") // outputs the values of the first wildcard segment
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

In certain scenarios, it can be useful to have an alternative approach to handle different types of parameters, not just strings. This can be achieved using a generic Query function known as Params[V GenericType](c Ctx, key string, defaultValue ...V) V. This function is capable of parsing a query string and returning a value of a type that is assumed and specified by V GenericType.

func Params[v GenericType](c Ctx, key string, default value ...V) V


// Get http://example.com/user/114
app.Get("/user/:id", func(c fiber.Ctx) error{
  fiber.Params[string](c, "id") // returns "114" as string.
  fiber.Params[int](c, "id") // returns 114 as integer
  fiber.Params[string](c, "number") // retunrs "" (default string type)
  fiber.Params[int](c, "number") // returns 0 (default integer value type)
})

The generic Params function supports returning the following data types based on V GenericType:

  • Integer: int, int8, int16, int32, int64
  • Unsigned integer: uint, uint8, uint16, uint32, uint64
  • Floating-point numbers: float32, float64
  • Boolean: bool
  • String: string
  • Byte array: []byte

Path

Contains the path part of the request URL. Optionally, you could override the path by passing a string. For internal redirects, you might want to call RestartRouting instead of Next.

func (c Ctx) Path(override ...string) string

// GET http://example.com/users?sort=desc

app.Get("/users", func(c fiber.Ctx) error {
  c.Path() // "/users"

  c.Path("/john")
  c.Path() // "/john"

  // ...
})

Port

Returns the remote port of the request.

func (c Ctx) Port() string

// GET http://example.com:8080
app.Get("/", func(c fiber.Ctx) error {
  c.Port() // "8080"

  // ...
})

Protocol

Contains the request protocol string: http or https for TLS requests.

func (c Ctx) Protocol() string

// GET http://example.com

app.Get("/", func(c fiber.Ctx) error {
  c.Protocol() // "http"

  // ...
})

Queries

Queries is a function that returns an object containing a property for each query string parameter in the route.

func (c Ctx) Queries() map[string]string

// GET http://example.com/?name=alex&want_pizza=false&id=

app.Get("/", func(c fiber.Ctx) error {
    m := c.Queries()
    m["name"] // "alex"
    m["want_pizza"] // "false"
    m["id"] // ""
    // ...
})

// GET http://example.com/?field1=value1&field1=value2&field2=value3

app.Get("/", func (c fiber.Ctx) error {
    m := c.Queries()
    m["field1"] // "value2"
    m["field2"] // value3
})

// GET http://example.com/?list_a=1&list_a=2&list_a=3&list_b[]=1&list_b[]=2&list_b[]=3&list_c=1,2,3

app.Get("/", func(c fiber.Ctx) error {
    m := c.Queries()
    m["list_a"] // "3"
    m["list_b[]"] // "3"
    m["list_c"] // "1,2,3"
})

// GET /api/posts?filters.author.name=John&filters.category.name=Technology

app.Get("/", func(c fiber.Ctx) error {
    m := c.Queries()
    m["filters.author.name"] // John
    m["filters.category.name"] // Technology
})

// GET /api/posts?tags=apple,orange,banana&filters[tags]=apple,orange,banana&filters[category][name]=fruits&filters.tags=apple,orange,banana&filters.category.name=fruits

app.Get("/", func(c fiber.Ctx) error {
    m := c.Queries()
    m["tags"] // apple,orange,banana
    m["filters[tags]"] // apple,orange,banana
    m["filters[category][name]"] // fruits
    m["filters.tags"] // apple,orange,banana
    m["filters.category.name"] // fruits
})

Query

This property is an object containing a property for each query string parameter in the route, you could pass an optional default value that will be returned if the query key does not exist.

:::info If there is no query string, it returns an empty string. :::

func (c Ctx) Query(key string, defaultValue ...string) string

// GET http://example.com/?order=desc&brand=nike

app.Get("/", func(c fiber.Ctx) error {
  c.Query("order")         // "desc"
  c.Query("brand")         // "nike"
  c.Query("empty", "nike") // "nike"

  // ...
})

:::info

Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable setting instead. Read more...

:::

In certain scenarios, it can be useful to have an alternative approach to handle different types of query parameters, not just strings. This can be achieved using a generic Query function known as Query[V GenericType](c Ctx, key string, defaultValue ...V) V. This function is capable of parsing a query string and returning a value of a type that is assumed and specified by V GenericType.

Here is the signature for the generic Query function:

func Query[V GenericType](c Ctx, key string, defaultValue ...V) V

Consider this example:

// GET http://example.com/?page=1&brand=nike&new=true

app.Get("/", func(c fiber.Ctx) error {
  fiber.Query[int](c, "page")     // 1
  fiber.Query[string](c, "brand") // "nike"
  fiber.Query[bool](c, "new")     // true

  // ...
})

In this case, Query[V GenericType](c Ctx, key string, defaultValue ...V) V can retrieve 'page' as an integer, 'brand' as a string, and 'new' as a boolean. The function uses the appropriate parsing function for each specified type to ensure the correct type is returned. This simplifies the retrieval process of different types of query parameters, making your controller actions cleaner.

The generic Query function supports returning the following data types based on V GenericType:

  • Integer: int, int8, int16, int32, int64
  • Unsigned integer: uint, uint8, uint16, uint32, uint64
  • Floating-point numbers: float32, float64
  • Boolean: bool
  • String: string
  • Byte array: []byte

Range

A struct containing the type and a slice of ranges will be returned.

func (c Ctx) Range(size int) (Range, error)

// Range: bytes=500-700, 700-900
app.Get("/", func(c fiber.Ctx) error {
  b := c.Range(1000)
  if b.Type == "bytes" {
      for r := range r.Ranges {
      fmt.Println(r)
      // [500, 700]
    }
  }
})

Redirect

Returns the Redirect reference.

For detailed information check the Redirect documentation.

func (c Ctx) Redirect() *Redirect

app.Get("/coffee", func(c fiber.Ctx) error {
    return c.Redirect().To("/teapot")
})

app.Get("/teapot", func(c fiber.Ctx) error {
    return c.Status(fiber.StatusTeapot).Send("🍵 short and stout 🍵")
})

Render

Renders a view with data and sends a text/html response. By default Render uses the default Go Template engine. If you want to use another View engine, please take a look at our Template middleware.

func (c Ctx) Render(name string, bind Map, layouts ...string) error

Request

Request return the *fasthttp.Request pointer

func (c Ctx) Request() *fasthttp.Request

app.Get("/", func(c fiber.Ctx) error {
  c.Request().Header.Method()
  // => []byte("GET")
})

Response

Response return the *fasthttp.Response pointer

func (c Ctx) Response() *fasthttp.Response

app.Get("/", func(c fiber.Ctx) error {
  c.Response().BodyWriter().Write([]byte("Hello, World!"))
  // => "Hello, World!"
  return nil
})

Reset

Reset the context fields by given request when to use server handlers.

func (c Ctx) Reset(fctx *fasthttp.RequestCtx)

It is used outside of the Fiber Handlers to reset the context for the next request.

RestartRouting

Instead of executing the next method when calling Next, RestartRouting restarts execution from the first method that matches the current route. This may be helpful after overriding the path, i. e. an internal redirect. Note that handlers might be executed again which could result in an infinite loop.

func (c Ctx) RestartRouting() error

app.Get("/new", func(c fiber.Ctx) error {
  return c.SendString("From /new")
})

app.Get("/old", func(c fiber.Ctx) error {
  c.Path("/new")
  return c.RestartRouting()
})

Route

Returns the matched Route struct.

func (c Ctx) Route() *Route

// http://localhost:8080/hello


app.Get("/hello/:name", func(c fiber.Ctx) error {
  r := c.Route()
  fmt.Println(r.Method, r.Path, r.Params, r.Handlers)
  // GET /hello/:name handler [name]

  // ...
})

:::caution Do not rely on c.Route() in middlewares before calling c.Next() - c.Route() returns the last executed route. :::

func MyMiddleware() fiber.Handler {
  return func(c fiber.Ctx) error {
    beforeNext := c.Route().Path // Will be '/'
    err := c.Next()
    afterNext := c.Route().Path // Will be '/hello/:name'
    return err
  }
}

SaveFile

Method is used to save any multipart file to disk.

func (c Ctx) SaveFile(fh *multipart.FileHeader, path string) error

app.Post("/", func(c fiber.Ctx) error {
  // Parse the multipart form:
  if form, err := c.MultipartForm(); err == nil {
    // => *multipart.Form

    // Get all files from "documents" key:
    files := form.File["documents"]
    // => []*multipart.FileHeader

    // Loop through files:
    for _, file := range files {
      fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
      // => "tutorial.pdf" 360641 "application/pdf"

      // Save the files to disk:
      if err := c.SaveFile(file, fmt.Sprintf("./%s", file.Filename)); err != nil {
        return err
      }
    }
    return err
  }
})

SaveFileToStorage

Method is used to save any multipart file to an external storage system.

func (c Ctx) SaveFileToStorage(fileheader *multipart.FileHeader, path string, storage Storage) error

storage := memory.New()

app.Post("/", func(c fiber.Ctx) error {
  // Parse the multipart form:
  if form, err := c.MultipartForm(); err == nil {
    // => *multipart.Form

    // Get all files from "documents" key:
    files := form.File["documents"]
    // => []*multipart.FileHeader

    // Loop through files:
    for _, file := range files {
      fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
      // => "tutorial.pdf" 360641 "application/pdf"

      // Save the files to storage:
      if err := c.SaveFileToStorage(file, fmt.Sprintf("./%s", file.Filename), storage); err != nil {
        return err
      }
    }
    return err
  }
})

Schema

Contains the request protocol string: http or https for TLS requests.

:::info Please use Config.EnableTrustedProxyCheck to prevent header spoofing, in case when your app is behind the proxy. :::

func (c Ctx) Schema() string

// GET http://example.com
app.Get("/", func(c fiber.Ctx) error {
  c.Schema() // "http"

  // ...
})

Secure

A boolean property that is true , if a TLS connection is established.

func (c Ctx) Secure() bool

// Secure() method is equivalent to:
c.Protocol() == "https"

Send

Sets the HTTP response body.

func (c Ctx) Send(body []byte) error

app.Get("/", func(c fiber.Ctx) error {
  return c.Send([]byte("Hello, World!")) // => "Hello, World!"
})

Fiber also provides SendString and SendStream methods for raw inputs.

:::tip Use this if you don't need type assertion, recommended for faster performance. :::

func (c Ctx) SendString(body string) error
func (c Ctx) SendStream(stream io.Reader, size ...int) error

app.Get("/", func(c fiber.Ctx) error {
  return c.SendString("Hello, World!")
  // => "Hello, World!"

  return c.SendStream(bytes.NewReader([]byte("Hello, World!")))
  // => "Hello, World!"
})

SendFile

Transfers the file from the given path. Sets the Content-Type response HTTP header field based on the filenames extension.

// SendFile defines configuration options when to transfer file with SendFile.
type SendFile struct {
  // FS is the file system to serve the static files from.
  // You can use interfaces compatible with fs.FS like embed.FS, os.DirFS etc.
  //
  // Optional. Default: nil
  FS fs.FS

  // When set to true, the server tries minimizing CPU usage by caching compressed files.
  // This works differently than the github.com/gofiber/compression middleware.
  // You have to set Content-Encoding header to compress the file.
  // Available compression methods are gzip, br, and zstd.
  //
  // Optional. Default value false
  Compress bool `json:"compress"`

  // When set to true, enables byte range requests.
  //
  // Optional. Default value false
  ByteRange bool `json:"byte_range"`

  // When set to true, enables direct download.
  //
  // Optional. Default: false.
  Download bool `json:"download"`

  // Expiration duration for inactive file handlers.
  // Use a negative time.Duration to disable it.
  //
  // Optional. Default value 10 * time.Second.
  CacheDuration time.Duration `json:"cache_duration"`

  // The value for the Cache-Control HTTP-header
  // that is set on the file response. MaxAge is defined in seconds.
  //
    // Optional. Default value 0.
  MaxAge int `json:"max_age"`
}

func (c Ctx) SendFile(file string, config ...SendFile) error

app.Get("/not-found", func(c fiber.Ctx) error {
  return c.SendFile("./public/404.html");

  // Disable compression
  return c.SendFile("./static/index.html", SendFile{
    Compress: false,
  });
})

:::info If the file contains an url specific character you have to escape it before passing the file path into the sendFile function. :::

app.Get("/file-with-url-chars", func(c fiber.Ctx) error {
  return c.SendFile(url.PathEscape("hash_sign_#.txt"))
})

:::info You can set CacheDuration config property to -1 to disable caching. :::

app.Get("/file", func(c fiber.Ctx) error {
  return c.SendFile("style.css", SendFile{
    CacheDuration: -1,
  })
})

:::info You can use multiple SendFile with different configurations in single route. Fiber creates different filesystem handler per config. :::

app.Get("/file", func(c fiber.Ctx) error {
  switch c.Query("config") {
    case "filesystem":
      return c.SendFile("style.css", SendFile{
        FS: os.DirFS(".")
      })
    case "filesystem-compress":
      return c.SendFile("style.css", SendFile{
        FS: os.DirFS("."),
        Compress: true,
      })
    case "compress":
      return c.SendFile("style.css", SendFile{
        Compress: true,
      })
    default:
      return c.SendFile("style.css")
  }

  return nil
})

:::info For sending multiple files from embedded file system this functionality can be used :::

SendStatus

Sets the status code and the correct status message in the body, if the response body is empty.

:::tip You can find all used status codes and messages here. :::

func (c Ctx) SendStatus(status int) error

app.Get("/not-found", func(c fiber.Ctx) error {
  return c.SendStatus(415)
  // => 415 "Unsupported Media Type"

  c.SendString("Hello, World!")
  return c.SendStatus(415)
  // => 415 "Hello, World!"
})

SendStream

Sets response body to a stream of data and add optional body size.

func (c Ctx) SendStream(stream io.Reader, size ...int) error

app.Get("/", func(c fiber.Ctx) error {
  return c.SendStream(bytes.NewReader([]byte("Hello, World!")))
  // => "Hello, World!"
})

SendString

Sets the response body to a string.

func (c Ctx) SendString(body string) error

app.Get("/", func(c fiber.Ctx) error {
  return c.SendString("Hello, World!")
  // => "Hello, World!"
})

Set

Sets the response’s HTTP header field to the specified key, value.

func (c Ctx) Set(key string, val string)

app.Get("/", func(c fiber.Ctx) error {
  c.Set("Content-Type", "text/plain")
  // => "Content-type: text/plain"

  // ...
})

SetUserContext

Sets the user specified implementation for context interface.

func (c Ctx) SetUserContext(ctx context.Context)

app.Get("/", func(c fiber.Ctx) error {
  ctx := context.Background()
  c.SetUserContext(ctx)
  // Here ctx could be any context implementation

  // ...
})

Stale

https://expressjs.com/en/4x/api.html#req.stale

func (c Ctx) Stale() bool

Status

Sets the HTTP status for the response.

:::info Method is a chainable. :::

func (c Ctx) Status(status int) Ctx

app.Get("/fiber", func(c fiber.Ctx) error {
  c.Status(fiber.StatusOK)
  return nil
}

app.Get("/hello", func(c fiber.Ctx) error {
  return c.Status(fiber.StatusBadRequest).SendString("Bad Request")
}

app.Get("/world", func(c fiber.Ctx) error {
  return c.Status(fiber.StatusNotFound).SendFile("./public/gopher.png")
})

String

Returns unique string representation of the ctx.

func (c Ctx) String() string

app.Get("/", func(c fiber.Ctx) error {
  c.String() // => "#0000000100000001 - 127.0.0.1:3000 <-> 127.0.0.1:61516 - GET http://localhost:3000/"

  // ...
})

Subdomains

Returns a string slice of subdomains in the domain name of the request.

The application property subdomain offset, which defaults to 2, is used for determining the beginning of the subdomain segments.

func (c Ctx) Subdomains(offset ...int) []string

// Host: "tobi.ferrets.example.com"

app.Get("/", func(c fiber.Ctx) error {
  c.Subdomains()  // ["ferrets", "tobi"]
  c.Subdomains(1) // ["tobi"]

  // ...
})

Type

Sets the Content-Type HTTP header to the MIME type listed here specified by the file extension.

:::info Method is a chainable. :::

func (c Ctx) Type(ext string, charset ...string) Ctx

app.Get("/", func(c fiber.Ctx) error {
  c.Type(".html") // => "text/html"
  c.Type("html")  // => "text/html"
  c.Type("png")   // => "image/png"

  c.Type("json", "utf-8")  // => "application/json; charset=utf-8"

  // ...
})

UserContext

UserContext returns a context implementation that was set by user earlier or returns a non-nil, empty context, if it was not set earlier.

func (c Ctx) UserContext() context.Context

app.Get("/", func(c fiber.Ctx) error {
  ctx := c.UserContext()
  // ctx is context implementation set by user

  // ...
})

Vary

Adds the given header field to the Vary response header. This will append the header, if not already listed, otherwise leaves it listed in the current location.

:::info Multiple fields are allowed. :::

func (c Ctx) Vary(fields ...string)

app.Get("/", func(c fiber.Ctx) error {
  c.Vary("Origin")     // => Vary: Origin
  c.Vary("User-Agent") // => Vary: Origin, User-Agent

  // No duplicates
  c.Vary("Origin") // => Vary: Origin, User-Agent

  c.Vary("Accept-Encoding", "Accept")
  // => Vary: Origin, User-Agent, Accept-Encoding, Accept

  // ...
})

ViewBind

Add vars to default view var map binding to template engine. Variables are read by the Render method and may be overwritten.

func (c Ctx) ViewBind(vars Map) error

app.Use(func(c fiber.Ctx) error {
  c.ViewBind(fiber.Map{
    "Title": "Hello, World!",
  })
})

app.Get("/", func(c fiber.Ctx) error {
  return c.Render("xxx.tmpl", fiber.Map{}) // Render will use Title variable
})

Write

Write adopts the Writer interface

func (c Ctx) Write(p []byte) (n int, err error)

app.Get("/", func(c fiber.Ctx) error {
  c.Write([]byte("Hello, World!")) // => "Hello, World!"

  fmt.Fprintf(c, "%s\n", "Hello, World!") // "Hello, World!Hello, World!"
})

Writef

Writef adopts the string with variables

func (c Ctx) Writef(f string, a ...any) (n int, err error)

app.Get("/", func(c fiber.Ctx) error {
  world := "World!"
  c.Writef("Hello, %s", world) // => "Hello, World!"

  fmt.Fprintf(c, "%s\n", "Hello, World!") // "Hello, World!Hello, World!"
})

WriteString

WriteString adopts the string

func (c Ctx) WriteString(s string) (n int, err error)

app.Get("/", func(c fiber.Ctx) error {
  c.WriteString("Hello, World!") // => "Hello, World!"

  fmt.Fprintf(c, "%s\n", "Hello, World!") // "Hello, World!Hello, World!"
})

XHR

A Boolean property, that is true, if the request’s X-Requested-With header field is XMLHttpRequest, indicating that the request was issued by a client library such as [jQuery](https://api.jquery.com/jQuery.ajax/).

func (c Ctx) XHR() bool

// X-Requested-With: XMLHttpRequest

app.Get("/", func(c fiber.Ctx) error {
  c.XHR() // true

  // ...
})

XML

Converts any interface or string to XML using the standard encoding/xml package.

:::info XML also sets the content header to application/xml. :::

func (c Ctx) XML(data any) error

type SomeStruct struct {
  XMLName xml.Name `xml:"Fiber"`
  Name    string   `xml:"Name"`
  Age     uint8    `xml:"Age"`
}

app.Get("/", func(c fiber.Ctx) error {
  // Create data struct:
  data := SomeStruct{
    Name: "Grame",
    Age:  20,
  }

  return c.XML(data)
  // <Fiber>
  //     <Name>Grame</Name>
  //    <Age>20</Age>
  // </Fiber>
})