(Node.js) PayPal -- Get an OAuth 2.0 Access Token

Demonstrates how to send a request to get a PayPal OAuth2 access token. Sends an HTTP request equivalent to the following:

curl https://api.sandbox.paypal.com/v1/oauth2/token \
  -H "Accept: application/json" \
  -H "Accept-Language: en_US" \
  -u "Client-Id:Secret" \
  -d "grant_type=client_credentials"

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // Note: Requires Chilkat v9.5.0.64 or greater.

    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var rest = new chilkat.Rest();

    // Make the initial connection.
    // A single REST object, once connected, can be used for many PayPal REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    var bAutoReconnect = true;
    var success = rest.Connect("api.sandbox.paypal.com",443,true,bAutoReconnect);
    if (success !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // Duplicate this request:

    // 	curl https://api.sandbox.paypal.com/v1/oauth2/token \
    // 	  -H "Accept: application/json" \
    // 	  -H "Accept-Language: en_US" \
    // 	  -u "Client-Id:Secret" \
    // 	  -d "grant_type=client_credentials"

    rest.AddHeader("Accept","application/json");
    rest.AddHeader("Accept-Language","en_US");

    // For additional help on where to find  your client ID and API secret, see PayPal Client_ID and API_Secret
    rest.SetAuthBasic("PAYPAL_REST_API_CLIENT_ID","PAYPAL_REST_API_SECRET");

    rest.AddQueryParam("grant_type","client_credentials");

    var responseStr = rest.FullRequestFormUrlEncoded("POST","/v1/oauth2/token");
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    console.log(rest.LastRequestHeader);

    // A sample response:

    // 	{
    // 	  "scope": "https://api.paypal.com/v1/payments/.* https://api.paypal.com/v1/vault/credit-card https://api.paypal.com/v1/vault/credit-card/.*",
    // 	  "access_token": "EEwJ6tF9x5WCIZDYzyZGaz6Khbw7raYRIBV_WxVvgmsG",
    // 	  "token_type": "Bearer",
    // 	  "app_id": "APP-6XR95014BA15863X",
    // 	  "expires_in": 28800
    // 	}

    var json = new chilkat.JsonObject();
    json.Load(responseStr);
    json.EmitCompact = false;

    // Check the response status code.  A 200 indicates success..
    if (rest.ResponseStatusCode !== 200) {
        console.log(json.Emit());
        console.log("Failed.");
        return;
    }

    // Given that the access token expires in approx 8 hours,
    // let's record the date/time this token was created.
    // This will allow us to know beforehand if the token
    // is expired (and we can then fetch a new token).
    var dateTime = new chilkat.CkDateTime();
    var bLocalTime = false;
    var dtNow = dateTime.GetAsUnixTime(bLocalTime);
    json.AppendInt("tokenCreateTimeUtc",dtNow);

    // Examine the access token and save to a file.
    console.log("Access Token: " + json.StringOf("access_token"));
    console.log("Full JSON Response:");
    console.log(json.Emit());

    var sbResponse = new chilkat.StringBuilder();
    sbResponse.Append(json.Emit());
    var bEmitBom = false;
    sbResponse.WriteFile("qa_data/tokens/paypal.json","utf-8",bEmitBom);

}

chilkatExample();