The MtGox API provides methods to access information from the market, place orders, and more.
Two APIs are currently available:
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...
|kind of field||...divide by||...multiply by|
|BTC (volume, amount)||1E8 (100,000,000)||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.
List of the currency symbols available with the API:
USD, AUD, CAD, CHF, CNY, DKK, EUR, GBP, HKD, JPY, NZD, PLN, RUB, SEK, SGD, THB
Date and time
Most dates you will find in mtgox API are UNIX time
Most programming languages should have tools for managing those timestamps