API is based on REST principles. The client makes HTTP requests to Paysera system, providing information about the intended action. HTTP verbs GET, POST, PUT and DELETE are used in this API. In POST and PUT requests content request is usually provided in JSON format by using UTF-8 encoding. If some other format is used, it is specified in the method description.

Paysera system provides JSON encoded response to each request. HTTP status code identifies the status of the request - for successful requests, status code 200 is returned. In case of an error, some information like a code and description is provided to debug the problem more easily, so that the client could try to decode the response even if an error code is returned.

If some elements of returned structure are optional, they can be skipped. That is, null is not returned, the JSON element is entirely skipped. Client should handle these situations and do not assert that the element will definitely exist if it's optional.

Errors and response codes

In case of a success, API returns status code 200. In case of an error, the status code differs from case to case.The client should always check the response status code to know what kind of response is given. In case of an error, response body is the error object. It's structure is provided in the table below. Basic error codes (available in all API methods) are the following:

• invalid_request (status code 400) - Request content is invalid
• invalid_parameters (status code 400) - Some required parameter is missing or it's format is invalid
• invalid_state (status code 409) - Requested action cannot be made to the current state of resource
• unauthorized (status code 401) - Authentication parameters are not provided or are incorrect
• forbidden (status code 403) - The client has no right to access the requested resource or perform the requested action
• not_found (status code 404) - Resource was not found
• internal_server_error (status code 500) - Unexpected internal system error
• not_acceptable (status code 406) - Unknown request or response format

Some other probable error codes are provided in descriptions of methods.

Error response example

HTTP/1.1 403 Forbidden
Content-type: application/json;charset=utf-8

{
    "error": "forbidden",
    "error_description": "This resource is assigned to other project, client has no rights to read it"
}