Simplest way of obtaining MtGox exchange rate via an API?

Question

I want to do a simple app that refreshes every minute to tell me the current exchange rate by Mtgox but I have a problem interpreting the JSON that some APIs return:

• Mtgox's fast ticker returns this JSON. The question is, what's the value that I have to retrieve? There are a lot and I don't understand them, and I don't find proper docs.

• Bitcoincharts' API has the Markets Data endpoint, and it returns the market I want under the symbol "mtgoxUSD", however it tells me the date time of latest trade, the last buy/ask, but doesn't tell me the exchange rate of the latest trade.

Am I missing something?

Answer 1

JSON can be a little hard to read because it's generally meant to be served without characters such as spaces and newlines that would make it human-readable.

Here's output from the fast ticker:

{
  "result":"success",
  "data":{
    "last_local":{
      "value":"136.87303",
      "value_int":"13687303",
      "display":"$136.87",
      "display_short":"$136.87",
      "currency":"USD"
    },
    "last":{
      "value":"136.87303",
      "value_int":"13687303",
      "display":"$136.87",
      "display_short":"$136.87",
      "currency":"USD"
    },
    "last_orig":{
      "value":"136.87303",
      "value_int":"13687303",
      "display":"$136.87",
      "display_short":"$136.87",
      "currency":"USD"
    },
    "last_all":{
      "value":"136.87303",
      "value_int":"13687303",
      "display":"$136.87",
      "display_short":"$136.87",
      "currency":"USD"
    },
    "buy":{
      "value":"136.10500",
      "value_int":"13610500",
      "display":"$136.11",
      "display_short":"$136.11",
      "currency":"USD"
    },
    "sell":{
      "value":"136.87250",
      "value_int":"13687250",
      "display":"$136.87",
      "display_short":"$136.87",
      "currency":"USD"
    },
    "now":"1381085718504609"
  }
}

The "result" item is always guaranteed to be there, but has of course varying content based on whether or not the call was successful. The "data" element contains a series of prices, with each name indicating its price.

Most JSON parsers in interpreted languages such as Ruby, PHP, and Python parse JSON into a hash or dictionary. You'd want the value of the "value" key of the "last" key of the "data" key.

Here's a one-liner version in Ruby for the v2 ticker:

ruby -e '%w(open-uri json).each{|b| require b}; open("http://data.mtgox.com/api/2/BTCUSD/money/ticker_fast") {|d| puts JSON.parse(d.read)["data"]["last"]["value"]}'

Or something a little more readable:

require "open-uri" 
require "json"

open("http://data.mtgox.com/api/2/BTCUSD/money/ticker_fast") do |d| 
  json = JSON.parse(d.read)
  puts json["data"]["last"]["value"]
end

Here's a one-liner version in Ruby for the old ticker:

ruby -e '%w(open-uri json).each{|b| require b}; open("https://mtgox.com/api/1/BTCUSD/ticker") {|d| puts JSON.parse(d.read)["return"]["last"]["value"]}'

Or something a little more readable:

require "open-uri" 
require "json"

open("https://mtgox.com/api/1/BTCUSD/ticker") do |d| 
  json = JSON.parse(d.read)
  puts json["return"]["last"]["value"]
end

Answer 2

Ok this should answer your question,

import urllib2, json

x = float(json.loads(urllib2.urlopen('https://mtgox.com/api/1/BTCUSD/ticker').read())['return']['last']['value'])

print x

This returns the last value for the MTGox USD price for bitcoins

Answer 3

This here is a bitcoin ticker app it shows the MTGox bitcoin price with a small lag and is self refreshing. It also supports GBP, EUR and Yen. This is the link to the blog post http://bitkapp.com/blog/bitcoin-price-ticker/

The simplest way of receiving the bitcoin exchange rate without a self refreshing feature is done by the following python script.

import json
import urllib2
from Tkinter import *

url='http://api.bitcoincharts.com/v1/markets.json'
req=urllib2.Request(url)
response=urllib2.urlopen(req).read()
output=json.loads(response)

mtusd_price = output[-10]['avg']
mteur_price = output[31]['avg']
mtgbp_price = output[44]['avg']

MTUSD= 'USD' + ' ' + str(mtusd_price)
MTEUR= 'EUR' + ' ' + str(mteur_price)
MTGBP = 'GBP' + ' ' + str(mtgbp_price)

root= Tk()
root.title("Bitcoin Price")
root.geometry("250x100")

USD = Label(root, text=MTUSD)
EUR = Label(root, text=MTEUR)
GBP = Label(root, text=MTGBP)
USD.pack()
EUR.pack()
GBP.pack()
mainloop()

When you run this script it will open a window displaying the price at that instant in USD, EUR and GBP.

Im sorry for previous post as it was obviously not clear enough.