This document is intended to assist software developers who want to develop applications using Changer.com API. It fully documents our application programming interface (API) that allows developers to interact with our system.

To use the information provided here, you should first have access to an active Changer.com account. You should also be familiar with:

• RESTful web services
• HTTP/1.1
• JSON (JavaScript Object Notation)

Our Application Program Interface will allow you to automate the process of making exchanges, receiving information about your account, fetching history of exchanges and transactions within your own software.

Since our API is based on REST principles, it's very easy to write and test applications. You can use your browser to access URLs, and you can use pretty much any HTTP client in any programming language to interact with the API.

All responses from Changer.com API are in JSON format.

Changer.com API supports CORS (Cross-origin Resource sharing) to allow access directly from a browser or client side only application.

You can use our API in two ways, public or authenticated mode.

Public mode will allow you to get exchange rates and limits as well as make exchanges and check their status without owning an account at Changer.com, while authenticated mode can be used to track your exchanges within your account and benefits from our Discount System.

If you want to use our API in authenticated mode (remember: this is OPTIONAL), you have to sign in your Changer.com account and create new API keys filling the form that will show up on the top of this page. Our application will generate your Api-Key and Api-Secure keys, which are both needed to properly make authenticated calls to our Application Program Interface.

API Authentication is based on the Api-Key and Api-Secure keys secrecy. If any of those get compromised, you should immediately disable and revoke (i.e. delete) the API from your account.

Changer.com REST API is served over HTTPS. To ensure data privacy, unencrypted HTTP is not supported. The Base URL for all the requests is:

https://www.changer.com/api/v2

Each request to our API needs to be authorized using your API-Key, an HMAC (Hash-based Message Authentication Code) signed with your API-Secure key and to avoid relay attacks also a timestamp. The three parameters are bundled in the HTTP Request using additional HTTP Headers, API-Key, Api-Sign and Api-Timestamp.

• Api-Key: The same as generated by our system when you created the API.
• Api-Sign: message digest as lowercase hexits, generated using HMAC-SHA256 algorithm. Constructed from the the following concatenated strings: [API Method URL]:[POST Parameters]:[Timestamp].
• Api-Timestamp: current timestamp in UNIX format.

Here is an example written in PHP on how to generate the API-Sign header.

$apiKey = '{your Api-Key}';
$apiSecure = '{your Api-Secure}';

$apiURL = '/api/v2/rates/pmUSD/bitcoinBTC'; // Replace with the API Method you want to call
$postData = http_build_query($postData); // URL-Encoded query string like: param0=foo&param1=bar (empty on 'method GET' requests)
$timestamp = time(); // Use current time stamp

$apiSign = hash_hmac('sha256', $apiURL.':'.$postData.':'.$timestamp, $apiSecure); // This is your generated API-Sign header

Resource URI

https://www.changer.com/api/v2/rates/<send>/<receive>

Valid <send> and <receive> parameters are:

• pm_USD
• pmvoucher_USD
• okpay_USD
• payeer_USD
• advcash_USD
• bitcoin_BTC
• ethereum_ETH
• dash_DASH
• monero_XMR
• litecoin_LTC
• dogecoin_DOGE
• zcash_ZEC
• ethereumclassic_ETC
• augur_REP
• golem_GNT
• gnosis_GNO
• lisk_LSK
• bytecoin_BCN
• peercoin_PPC
• clams_CLAM
• namecoin_NMC

Method

GET Query Arguments

Response

A successful call will return a JSON object.

{
    pair: {
        send: "pmUSD",
        receive : "bitcoinBTC"
    },
    rate: 0.0045,
    receive_amount: 0.45,
}

Resource URI

https://www.changer.com/api/v2/limits/<send>/<receive>

Valid <send> and <receive> parameters are:

• pm_USD
• pmvoucher_USD
• okpay_USD
• payeer_USD
• advcash_USD
• bitcoin_BTC
• ethereum_ETH
• dash_DASH
• monero_XMR
• litecoin_LTC
• dogecoin_DOGE
• zcash_ZEC
• ethereumclassic_ETC
• augur_REP
• golem_GNT
• gnosis_GNO
• lisk_LSK
• bytecoin_BCN
• peercoin_PPC
• clams_CLAM
• namecoin_NMC

Method

GET Query Arguments

Response

A successful call will return a JSON object.

{
    pair: {
        send: "pmUSD",
        receive : "bitcoinBTC"
    },
    limits: {
        min_amount: 1,
        max_amount: 9986.44
    }
}

Resource URI

https://www.changer.com/api/v2/exchange

Method

POST Data

Response

A successful call will return a JSON object.

{
    pair: {
        send: "pmUSD",
        receive : "bitcoinBTC"
    },
    limits: {
        min_amount: 1,
        max_amount: 9986.44
    },
    exchange_id: "6ccd780c-baba-1026-9564-0040f4311e29",
    send_amount: 100,
    rate: 224.7191,
    receive_amount: 0.4450,
    receiver_id : "1XXXXxxXXx1XXx2xxX3XX456xXx",
    payee: "U1407474",
    batch_required : true|false,
    expiration: 1430756486
}

Resource URI

https://www.changer.com/api/v2/exchange/<exchange_id>

You must replace <exchange_id> with the UUID returned in the previous call.

Method

POST Data

Response

A successful call will return a JSON object.

{
    success: "true",
    exchange_id: "6ccd780c-baba-1026-9564-0040f4311e29",
    send_amount: 100,
    rate: 224.7191,
    receive_amount: 0.4450,
    receiver_id: "1XXXXxxXXx1XXx2xxX3XX456xXx"
}

In case of a failure, an error name/key pair will be returned.

Resource URI

https://www.changer.com/api/v2/exchange/<exchange_id>

You must replace <exchange_id> with the UUID of the exchange you want to check the status of.

Method

GET Query Arguments

Response

A successful call will return a JSON object.

{
    pair: {
        send: "pmUSD",
        receive : "bitcoinBTC"
    },
    exchange_id: "6ccd780c-baba-1026-9564-0040f4311e29",
    send_amount: 100,
    rate: 224.7191,
    receive_amount: 0.4450,
    receiver_id : "1XXXXxxXXx1XXx2xxX3XX456xXx",
    status: "processing",
    exchange_time: 1430756126,
    processed_time: null,
    batch_out: null,
}

Here you can download ready-made modules in different programming languages to make integration with your software fast and hassle-free.

More coming soon...