Article

How to implement RKD JSON application with Python chapter 1: the basic

July 15,2017

Wasin Waeosri

How to implement RKD JSON application with Python chapter 1: the basic

Overview

The Refinitiv Knowledge Direct (RKD) API (formerly known as TRKD API) integrates into your website, trading platform, company intranet/extranet, advisory portal and mobile applications to provide up-to-date financial market data, news and analytics and powerful investment tools.

RKD offers a wide range of Refinitiv' information and services delivered in a request-response scenario via web services using today's industry standard protocols (SOAP/XML and REST/JSON). Connectivity can be via HTTP and HTTPS, over the Internet or Delivery Direct. All data are snapshot (non-streaming) data.

With new HTTP JSON services, developers can integrate RKD information to their application easier then before. This article provides an information regarding the basic knowledge of how to implement RKD JSON application with Python language.

RKD JSON application implementation process

The JSON application requires the following steps to consume data from RKD API services

Authentication with RKD Authentication service to get an authen token
Send a request message with the required input information and authen token to the interested RKD service

Authentication Process

The consumer application needs to authenticate with RKD Service Token with the following information

Username
Application ID (AppID)
Password

Once the application is permissioned success, the application gets the following information from RKD

Token: an encrypted, expiring string that securely identifies the service user (aka service Token)
Expiration: Token expires after a configurable time period. The default expiration is 90 minutes.

Subscribe Data Process

After the application get the Service Token, the application can subscribes data to the RKD service. The application needs to set the Application ID and service Token with the request message HTTP header to identify the permissioned.

X-Trkd-Auth-ApplicationID: Application ID
X-Trkd-Auth-Token: service Token

Data Format

All request and response messages of the RKD REST Services are in the JSON format. We will use the Python json library to encode the request message via the HTTP Post request. For the response message, we will use the JSON builtin encoder of the requests library to decode incoming JSON data.

    	
            {
    "CreateServiceToken_Response_1": {
        "Expiration": "2017-05-09T08:55:52.6017Z",
        "Token": "AAA"
    }
}

example 1: Example JSON message response for RKD Authenticacion CreateServiceToken_1 service

"trkd_authen.py" Example Application

RKD API uses an encrypted, expiring token to authenticate each request. To create this token, your application submits credentials to the Token Management service. The Token Management service authenticates the credentials and returns the token.

This section describes how to implement the trkd_authen.py script that performs authentication with the TRDK API with the inputted username, password and appid via the command line.

RKD Sservice Token Detail

RKD Service Token URL and Header

The URL enponint for the RKD Service Token is following: https://api.rkd.refinitiv.com/api/TokenManagement/TokenManagement.svc/REST/Anonymous/TokenManagement_1/CreateServiceToken_1

Header:

Content-type = application/json;charset=utf-8

Method:

Post

RKD Service TOKEN Request Message

The CreateServiceToken_1 operation requires the following information to perform authentication

ApplicationID
Username
Password

The request message structure is following

    	
            {
    “CreateServiceToken_Request_1”: {
        “ApplicationID”: <application id>,
        “Username”: <username>,
        “Password”: <password>
    }
}

The example of the response message is shown below

    	
            { 
    "CreateServiceToken_Response_1": { 
        "Expiration": "2016-09-26T09:42:54.4335265Z", 
        "Token": "674E12E4EF35F181602672D5529D98379D4B42216057C7FF…" 
    }
}

IMPLEMENTATION DETAILS

Firstly, we create a file named “trkd_authen.py” in the working directory. Then we import all required libraries at the top of the source code.

    	
            import os 
import sys 
import requests 
import json 
import getpass

2. Then we add the code to receive the inputted username, password and application id from the console.

    	
            ##Get username, password and applicationid 
username = input('Please input username: ') 
##use getpass.getpass to hide user inputted password 
password = getpass.getpass(prompt='Please input password: ') 
appid = input('Please input appid: ')

3. Next, we create the request message (authenMsg), the url (authenURL) and headers variables.

    	
            ##create authentication request URL, message and header
authenMsg = {'CreateServiceToken_Request_1': { 'ApplicationID':appid, 'Username':username,'Password':password }}
authenURL = 'https://api.rkd.refinitiv.com/api/TokenManagement/TokenManagement.svc/REST/Anonymous/TokenManagement_1/CreateServiceToken_1'
headers = {'content-type': 'application/json;charset=utf-8'}

4. Then we create a HTTP Post request message to the RKD Service Token endpoint that specified in the authenURL variable with the authenMsg request message. We use the requests.post function of the requests library to handle this operation.

    	
            ## send request 
result = requests.post(authenURL, data = json.dumps(authenMsg), headers=headers)

5. Finally, we check if the status code is 200 (OK), prints out the Token and Expiration. Alterwise, prints out "request fail message" and raise an exception. If the return status code is 500, prints out the whole return JSON message.

    	
            ## request success
if result.status_code == 200:
    print('Request success')
    print('response status %s'%(result.status_code))
    ## get Token
    token = result.json()['CreateServiceToken_Response_1']['Token']
    print('Token: %s'%(token))
    ## get expiraion
    expire = result.json()['CreateServiceToken_Response_1']['Expiration']
    print('Expire: %s'%(expire))
## handle error
else:
    print('Request fail')
    print('response status %s'%(result.status_code))
    if result.status_code == 500: ## if username or password or appid is wrong
        print('Error: %s'%(result.json()))
    result.raise_for_status()

Running the application

The application source code is available at GitHub. You can get it via the following git command

    	
            $>git clone git@github.com:Refinitiv-API-Samples/Example.TRKD.Python.HTTPJSON.git

All RKD HTTP JSON python examples support Python 3 only and they require the the requests library, please check the README.md in the source code project for more detail.

You can run trkd_authen.py application via the following command

    	
            $>python trkd_authen.py

Then input your username, password and application id as shown in the Figure-1 below.

Figure-1: The trkd_authen receives username, password and appid via commandline

The result is shown in the Figure-2 below

Figure-2: The Authentication result from RKD Service Token endpoint

Please note that the application must keeps the application id and this service Token for futher operations.

Conclusion

All RKD HTTP JSON applications require authenticaiton to access RKD data. The application needs to request for Service Token from RKD server, then keeps a response Service Token for later use in other request message header.