MtGox/API

2011-07-26T09:11:52Z

Ken: fixed ticker channel number, fixed ticker specification

The [[MtGox]] API provides various methods to access different informations from the market, place orders, and more.

Two APIs are available at this point: the HTTP api (available by posting to mtgox.com/code/*) and the websocket API.

==Number Formats==

In the "old API", currency- and amount-values (price, volume,...) were given as '''float'''. These values are likely being deprecated and replaced by fields of the same name with "_int" as suffix. These are '''fixed-decimal''', so you have to move the decimal point yourself (divide). The exponent differs based on the kind of the value.

In order to convert the '''int''' to a '''decimal''' you can...

{| class="wikitable"
|-
! kind of field !! ...divide by !! ...multiply by
|-
| BTC (volume, amount) || 1E8 (10,000,000) || 0.00000001
|-
| USD (price) || 1E5 (100,000) || 0.00001
|-
| JPY (price) || 1E3 (1,000) || 0.001
|}

Implementation advice: it's probably best to use '''int''' or '''Decimal''' (if your language/db offers such a type) in your clients. Using '''float''' will likely lead to nasty rounding problems.

== HTTP API ==
This API is available in <nowiki>https://mtgox.com/api/*</nowiki>, and provides various informations. It also supports making an order, a withdraw, a deposit, etc. There is also a [[Finance::MtGox|Perl module]] for interacting with the HTTP API.

=== Authentication ===
Authentication is performed by signing each request using HMAC-SHA512. The request must contain an extra value "nonce" which must be an always incrementing numeric value. A reference implementation is provided here:
<source lang="php">
<?php

function mtgox_query($path, array $req = array()) {
// API settings
$key = '';
$secret = '';

// generate a nonce as microtime, with as-string handling to avoid problems with 32bits systems
$mt = explode(' ', microtime());
$req['nonce'] = $mt[1].substr($mt[0], 2, 6);

// generate the POST data string
$post_data = http_build_query($req, '', '&');

// generate the extra headers
$headers = array(
'Rest-Key: '.$key,
'Rest-Sign: '.base64_encode(hash_hmac('sha512', $post_data, base64_decode($secret), true)),
);

// our curl handle (initialize if required)
static $ch = null;
if (is_null($ch)) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MtGox PHP client; '.php_uname('s').'; PHP/'.phpversion().')');
}
curl_setopt($ch, CURLOPT_URL, 'https://mtgox.com/api/'.$path);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

// run the query
$res = curl_exec($ch);
if ($res === false) throw new Exception('Could not get reply: '.curl_error($ch));
$dec = json_decode($res, true);
if (!$dec) throw new Exception('Invalid data received, please make sure connection is working and requested API exists');
return $dec;
}

// example 1: get infos about the account, plus the list of rights we have access to
var_dump(mtgox_query('0/info.php'));

// old api (get funds)
var_dump(mtgox_query('0/getFunds.php'));

// trade example
// var_dump(mtgox_query('0/buyBTC.php', array('amount' => 1, 'price' => 15)));
</source>

=== Methods ===

==== 0/data/getTrades.php ====
This allows retrieving all trades which happened in the last 24 hours. The returned data is cached and may not reflect latest activity.

Parameters:
* since: Passing a tid in "since" allows retrieving all trades since that trade. The passed id is may not exist. Ie. to get all trades from the very beginning one would just call https://mtgox.com/code/data/getTrades.php?since=0 . since returns only 100 trades, and you can call the method again by passing the latest trade you have imported in since.

==== 0/history_[CUR].csv ====
Allows downloading the activity history for a given currency (BTC or USD for now).

== Websocket API ==
ported on 7/10/2011 from http://forum.bitcoin.org/index.php?topic=5855.0

===Connecting===

You can connect via: ws://websocket.mtgox.com/mtgox

The WebSocket protocol version used is that described in [http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00 draft-ietf-hybi-thewebsocketprotocol-00] (aka draft-00).

===Channels===

The websocket will subscribe you to some channels automatically:

{| class="wikitable"
|-
! Channel ID !! Description
|-
| dbf1dee9-4f2e-4a08-8cb7-748919a71b21 || trades (each time a trade happens, you get something here)
|-
| d5f06780-30a8-4a48-a2f8-7ed181b4a13f || the mtgox ticker (lots of updates, with often the same data)
|-
| 24e67e0d-1cad-4cc0-9e7a-f8523ef460fe || depth information in realtime (price + amount + type... type=1=Ask, type=2=Bid)
|}

Additionally each user has a "own" channel which streams informations about orders (new order, deleted order, etc) and trades only the user's trades).

Each message is a JSON-encoded object, with at least "op" element. The "op" element contains the operation to be done (for outgoing messages), or the type of message (for incoming messages).

===Possible outgoing commands===

'''unsubscribe''' Stop receiving messages from a channel (parameter "channel")

===Incoming Data===

====Ticker====
<source lang="javascript">
{
"channel":"d5f06780-30a8-4a48-a2f8-7ed181b4a13f",
"op":"private",
"origin":"broadcast",
"private":"ticker",
"ticker":{
"buy":0.9515,
"high":1,
"low":0.91,
"sell":0.9697,
"vol":34349
}
}
</source>

'''ticker''' contains the following:

{| class="wikitable"
|-
! Name !! Value
|-
| buy || highest bid as float
|-
| sell || lowest ask as float
|-
| high || maximum rate since last close as float
|-
| low || minimum rate since last close as float
|-
| vol || traded volume since last close
|}

====Trade====

<source lang="javascript">{
"channel":"dbf1dee9-4f2e-4a08-8cb7-748919a71b21",
"op":"private",
"origin":"broadcast",
"private":"trade",
"trade":{
"amount":2.71,
"amount_int":"271000000",
"date":1310279340,
"item":"BTC",
"price":14.43,
"price_currency":"USD",
"price_int":"1443000",
"tid":"1310279340877902",
"trade_type":"bid",
"type":"trade"
}
}
</source>

'''trade''' contains the following:

{| class="wikitable"
|-
! Name !! Value
|-
| amount || the traded amount in item (BTC), float, deprecated
|-
| amount_int || the traded amount * 1E8
|-
| date || unix timestamp of trade
|-
| item || What was this trade about
|-
| price || price per unit, float, deprecated
|-
| price_int || price in smallest unit as integer (5 decimals of USD, 3 in case of JPY)
|-
| price_currency || currency in which trade was completed
|-
| tid || Trade id (big integer, which is in fact trade timestamp in microseconds)
|-
| trade_type || Did this trade result from the execution of a bid or a ask?
|-
|}

====Depth====

Changes to the market depth data are broadcast so an up-to-date market depth can be kept by clients.

<source lang="javascript">{
"channel":"24e67e0d-1cad-4cc0-9e7a-f8523ef460fe",
"depth":{
"currency":"USD",
"item":"BTC",
"price":"14.43",
"price_int":"1443000",
"type":1,
"type_str":"ask",
"volume":"-2.71",
"volume_int":"-271000000"
},
"op":"private",
"origin":"broadcast",
"private":"depth"
}</source>

'''depth''' contains the following:

:{| class="wikitable"
|-
! Name !! Value
|-
| currency || the currency affected
|-
| item || the item (BTC)
|-
| price || price as a float, deprecated
|-
| price_int || the price at which volume change happened (5 decimal for USD, 3 for JPY)
|-
| type || 1=ask, 2=bid. deprecated, use type_str
|-
| type_str || type of order at this depth, either "ask" or "bid"
|-
| volume || the volume change as float, deprecated
|-
| volume_int || volume change * 1E8
|-
| ||
|-
| ||

|}

====Order update (private)====

<source lang="javascript">
{
"channel":"(partial key)",
"op":"private",
"order_upd":{
"amount":1000,
"darkStatus":0,
"date":1302836027,
"oid":"(oid)",
"price":0.9899,"status":1
},
"origin":"broadcast",
"private":"order_upd"
}</source>

'''order_upd''' cointains the following:

:{| class="wikitable"
|-
! Name !! Value
|-
| amount || change in volume of the order
|-
| darkStatus ||
|-
| oid || ID of the affected order
|-
| price ||
|-
| status ||
|}

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MtGox/API