Overview

Query Mechanics

The API supports GET requests and POST requests with Content-type equal to form-data or x-www-form-urlencoded
Data can be sent:

GET method - data is passed in GET parameters; when transferring complex structured data, such as multidimensional arrays, the following notation format is used:
{{domain}}/script.php?param_1=val&param_2[subParam_1]=val2& param_2[subParam_2]=val3&param_3=val4

POST method - data is transmitted in POST parameters. Structural data when working via POST are formed in a similar way.

Via XML - requests are also transmitted by the Post method, only in the only pg_xml parameter, presented in XML form:

<?xml version="1.0" encoding="utf-8"?><request><pg_param1>value1</pg_param><pg_param2>value2</pg_param></request>

Signature Formation

Any messages (requests and responses) between FreedomPay and the merchant are signed. To create a signature, you need to concatenate the following with a separator ;:

The name of the script being called (from the last / to the end or ?).

All message fields in alphabetical order, including the random string pg_salt, which consists of an arbitrary number of digits and Latin letters.

Additionally:

This rule is applied recursively to nested tags (only for XML).

Fields with the same name are taken in the order they appear in the message.

The payment password secret_key, which is set in the store settings and is known only to the merchant and FreedomPay.

The resulting concatenated string must then be hashed using MD5, and the hash should be added to the request or response as an additional parameter pg_sig. The MD5 hash is recorded as a 32-character lowercase hexadecimal string.
Either party may add additional parameters to the request or response that are not specified in the documentation. These parameters also participate in the signature calculation. A message is not signed, and thus the fields pg_salt and pg_sig are absent only in one case – when FreedomPay could not identify the merchant and therefore does not know its secret_key. In such a case, the field pg_error_code (numeric error code) takes the value 9998.
For a complete list of possible values of the field pg_error_code, see the Error Code Reference section.

Query Mechanics

Signature Formation

Example of request with signature

PHP example

Overview

Query Mechanics#

Signature Formation#

Example of request with signature#

PHP example#

Query Mechanics

Signature Formation

Example of request with signature

PHP example