View all our articles

Send custom HTTP headers in Go with Go-Resty

In this guide, we'll walk you through the process of sending custom HTTP headers when requesting an URL to be converted to PDF using PDFShift's API.

This can be useful to pass custom parameters to your server. It can help for instance to identify from where is coming the request, and add some extra layer of security.

package main

import (

func main() {
    // You can get an API key at
    apiKey := "sk_xxxxxxxxxxxx"

    params := map[string]interface{}{
        "source": "",
        "http_headers": map[string]string{
            "x-custom-header": "custom-value",
            "Authorization":   "Bearer {token}", // This allows you to authenticate PDFShift to your service in a custom way

    // Marshal the parameters into JSON
    jsonParams, err := json.Marshal(params)
    if err != nil {
        fmt.Println("Error marshaling JSON:", err)
    // Create a new Resty client
    client := resty.New()

    // Perform the request
    resp, err := client.R().
        SetHeader("Content-Type", "application/json").
        SetBasicAuth("api", apiKey).

    if err != nil {
        fmt.Println("Error performing request:", err)

    // Check response status code
    if resp.StatusCode() >= 400 {
        fmt.Printf("Request failed with status code %d: %s\n", resp.StatusCode(), string(resp.Body()))

    // Save the PDF document
    err = ioutil.WriteFile("result.pdf", resp.Body(), 0644)
    if err != nil {
        fmt.Println("Error saving PDF document:", err)

    fmt.Println("The PDF document was generated and saved to result.pdf")

This allows you to set specific HTTP headers that will be send along with the request PDFShift will make to your server. It can be helpful to authenticate the request that your backend can check against before converting it to PDF.

For further details on the http_headers property and its usage, please refer to our dedicated documentation.

We hope this guide was helpful. If you have any questions or noticed any issues on the code above,
feel free to drop us a line.