MtGox/API/HTTP/v2

API Version 2:

The V2 API URL is:

https://data.mtgox.com/api/2/

Documentation

unofficial documentation (So far the best we have) is provided at :

https://bitbucket.org/nitrous/mtgox-api/overview
(The bitcointalk forum link is: https://bitcointalk.org/index.php?topic=164404.0

official docs are on  :

https://github.com/MtGox/mtgox-doc

Technical Use Explanation:

The requested path (anything after the /2/) must now be included when you compute your hashed signature (Rest-Sign) for added security.

This is how it was done for version 1:

You have your params(post_data) = the word nonce, followed by the actual nonce integer (params = [(u'nonce',nonce)])

You have your header made up of Rest-Key (your API-KEY) and Rest-Sign (a hashed signature)

Rest-Sign is created by doing : base64encode( HMAC hash( base64decoded(API-secret), the nonce, with SHA512 digest))

What differs in version 2 is now : BEFORE the nonce, you are adding the relative path you are requesting(ie: BTCUSD/money/ticker) + a NUL char (ascii code 0).

The URL is now something along the lines of BTCUSD/money/order/add instead of BTCUSD/private/order/add in api1.
So in my python code below which is very readable you can see everything remains the same as API v1 except now we are using api2postdatatohash = path + chr(0) + post_data #new way to hash for API 2, includes path + NUL.

BTCUSD/money/order/quote <@MagicalTux> it estimate the result of running an order at a given price based on market depth

Code Examples:

C# :

https://github.com/pipe2grep/GoxSharp C# lib for V2 API and socketIO

Python v 2.7.3

http://pastebin.com/aXQfULyq - Remove any proprietary unlock_api_key stuff. You'll need json_ascii also. Works on API 0/1/2. Link to git-repo: genbtc's trader.python

Perl

https://en.bitcoin.it/wiki/MtGox/API/HTTP#PHP The Perl example on the main page is compatible with v2