fiber/docs/client/response.md

id	title	description	sidebar_position
response	📥 Response	Response methods of Gofiber HTTP client.	3

The Response structure in Gofiber's HTTP client represents the server's response to an HTTP request. It includes:

• Status Code: The HTTP status code returned by the server (e.g., 200 OK, 404 Not Found).
• Headers: All HTTP headers returned by the server, providing additional response-related information.
• Body: The response body content, which can be JSON, XML, plain text, or other formats.
• Cookies: Any cookies the server sent along with the response.

This structure makes it easy to inspect and handle the data sent back by the server.

type Response struct {
    client      *Client
    request     *Request
    cookie      []*fasthttp.Cookie
    RawResponse *fasthttp.Response
}

AcquireResponse

AcquireResponse returns a new (pooled) Response object. When finished, release it using ReleaseResponse to reduce GC overhead.

func AcquireResponse() *Response

ReleaseResponse

ReleaseResponse returns the Response object to the pool. Avoid using the response after releasing it to prevent data races.

func ReleaseResponse(resp *Response)

Status

Status returns the HTTP status message (e.g., OK, Not Found) associated with the response.

func (r *Response) Status() string

StatusCode

StatusCode returns the numeric HTTP status code of the response.

func (r *Response) StatusCode() int

Protocol

Protocol returns the HTTP protocol used (e.g., HTTP/1.1, HTTP/2) for the response.

func (r *Response) Protocol() string

Example

resp, err := client.Get("https://httpbin.org/get")
if err != nil {
    panic(err)
}

fmt.Println(resp.Protocol())

Output:

HTTP/1.1

Header

Header retrieves the value of a specific response header by key. If multiple values exist for the same header, this returns the first one.

func (r *Response) Header(key string) string

Headers

Headers returns an iterator over all response headers. Use maps.Collect() to convert them into a map if desired. The returned values are only valid until the response is released, so make copies if needed.

func (r *Response) Headers() iter.Seq2[string, []string] 

Example

resp, err := client.Get("https://httpbin.org/get")
if err != nil {
    panic(err)
}

for key, values := range resp.Headers() {
    fmt.Printf("%s => %s\n", key, strings.Join(values, ", "))
}

Output:

Date => Wed, 04 Dec 2024 15:28:29 GMT
Connection => keep-alive
Access-Control-Allow-Origin => *
Access-Control-Allow-Credentials => true

Example with maps.Collect()

resp, err := client.Get("https://httpbin.org/get")
if err != nil {
    panic(err)
}

headers := maps.Collect(resp.Headers())
for key, values := range headers {
    fmt.Printf("%s => %s\n", key, strings.Join(values, ", "))
}

Output:

Date => Wed, 04 Dec 2024 15:28:29 GMT
Connection => keep-alive
Access-Control-Allow-Origin => *
Access-Control-Allow-Credentials => true

Cookies

Cookies returns a slice of all cookies set by the server in this response. The slice is only valid until the response is released.

func (r *Response) Cookies() []*fasthttp.Cookie

Example

resp, err := client.Get("https://httpbin.org/cookies/set/go/fiber")
if err != nil {
    panic(err)
}

cookies := resp.Cookies()
for _, cookie := range cookies {
    fmt.Printf("%s => %s\n", string(cookie.Key()), string(cookie.Value()))
}

Output:

go => fiber

Body

Body returns the raw response body as a byte slice.

func (r *Response) Body() []byte

String

String returns the response body as a trimmed string.

func (r *Response) String() string

JSON

JSON unmarshals the response body into the provided variable v using JSON. v should be a pointer to a struct or a type compatible with JSON unmarshalling.

func (r *Response) JSON(v any) error

Example

type Body struct {
    Slideshow struct {
        Author string `json:"author"`
        Date   string `json:"date"`
        Title  string `json:"title"`
    } `json:"slideshow"`
}
var out Body

resp, err := client.Get("https://httpbin.org/json")
if err != nil {
    panic(err)
}

if err = resp.JSON(&out); err != nil {
    panic(err)
}

fmt.Printf("%+v\n", out)

Output:

{Slideshow:{Author:Yours Truly Date:date of publication Title:Sample Slide Show}}

XML

XML unmarshals the response body into the provided variable v using XML decoding.

func (r *Response) XML(v any) error

CBOR

CBOR unmarshals the response body into v using CBOR decoding.

func (r *Response) CBOR(v any) error

Save

Save writes the response body to a file or an io.Writer. If v is a string, it interprets it as a file path, creates the file (and directories if needed), and writes the response to it. If v is an io.Writer, it writes directly to it.

func (r *Response) Save(v any) error

Reset

Reset clears the Response object, making it ready for reuse by ReleaseResponse.

func (r *Response) Reset()

Close

Close releases both the associated Request and Response objects back to their pools.

:::warning After calling Close, any attempt to use the request or response may result in data races or undefined behavior. Ensure all processing is complete before closing. :::

func (r *Response) Close()