Script to view your Account Balance for your Discover Card

discover.go

package main

import (
	"fmt"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"os"
	"time"

	"github.com/PuerkitoBio/goquery"
)

var startURL = "https://discovercard.com/"
var postURL = "https://www.discovercard.com/cardmembersvcs/loginlogout/app/signin"
var homepageURL = "https://www.discovercard.com/cardmembersvcs/achome/homepage"

var userID = os.Args[1]
var password = os.Args[2]

func main() {
	// Save dem cookies
	jar, _ := cookiejar.New(nil)
	client := http.Client{nil, nil, jar, time.Minute}

	// Get base URL to grab cookie value
	req, err := http.NewRequest("GET", startURL, nil)
	_, err = client.Do(req)
	if err != nil {
		fmt.Println(err)
	}

	// Post the userID and password over
	resp, err := client.PostForm(postURL,
		url.Values{"userID": {userID}, "password": {password}})
	if err != nil {
		fmt.Println(err)
	}

	// Get the homepage
	resp, err = client.Get(homepageURL)
	if err != nil {
		fmt.Println(err)
	}
	if resp.Request.URL.String() != homepageURL {
		fmt.Println("Login failure :(")
		return
	}

	// Read and query document
	doc, err := goquery.NewDocumentFromResponse(resp)
	if err != nil {
		fmt.Println(err)
	}

	sel := doc.Selection.Find(".card-balances .amount")
	balance, _ := sel.Html()

	fmt.Println(balance)
}

Usage:

go run discover.go username password