(Node.js) Get a Google Sheets OAuth2 Access Token

Demonstrates how to get a Google Sheets OAuth2 access token from a desktop application or script.

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() {

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

    var oauth2 = new chilkat.OAuth2();
    var success;

    // For Google OAuth2, set the listen port equal to the port used
    // in the Authorized Redirect URL for the Client ID.
    // For example, in this case the Authorized Redirect URL would be http://localhost:55568/
    // Your app should choose a port not likely not used by any other application.
    oauth2.ListenPort = 55568;

    oauth2.AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth";
    oauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token";

    // Replace these with actual values.
    oauth2.ClientId = "GOOGLE-CLIENT-ID";
    oauth2.ClientSecret = "GOOGLE-CLIENT-SECRET";

    oauth2.CodeChallenge = true;
    oauth2.CodeChallengeMethod = "S256";

    // These are the scopes for Google Sheets:
    // https://www.googleapis.com/auth/spreadsheets 	read/write access to spreadsheets
    // https://www.googleapis.com/auth/spreadsheets.readonly 	read-only access to spreadsheets
    oauth2.Scope = "https://www.googleapis.com/auth/spreadsheets";

    // Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    var url = oauth2.StartAuth();
    if (oauth2.LastMethodSuccess !== true) {
        console.log(oauth2.LastErrorText);
        return;
    }

    // At this point, your application should load the URL in a browser.
    // For example, 
    // in C#: System.Diagnostics.Process.Start(url);
    // in Java: Desktop.getDesktop().browse(new URI(url));
    // in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
    //              wsh.Run url
    // in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
    // in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
    // The QuickBooks account owner would interactively accept or deny the authorization request.

    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...
    // Add the code to load the url in a web browser here...

    // Now wait for the authorization.
    // We'll wait for a max of 30 seconds.
    var numMsWaited = 0;
    while ((numMsWaited < 30000) && (oauth2.AuthFlowState < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited+100;
    }

    // If there was no response from the browser within 30 seconds, then 
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (oauth2.AuthFlowState < 3) {
        oauth2.Cancel();
        console.log("No response from the browser!");
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (oauth2.AuthFlowState == 5) {
        console.log("OAuth2 failed to complete.");
        console.log(oauth2.FailureInfo);
        return;
    }

    if (oauth2.AuthFlowState == 4) {
        console.log("OAuth2 authorization was denied.");
        console.log(oauth2.AccessTokenResponse);
        return;
    }

    if (oauth2.AuthFlowState !== 3) {
        console.log("Unexpected AuthFlowState:" + oauth2.AuthFlowState);
        return;
    }

    // Save the full JSON access token response to a file.
    var sbJson = new chilkat.StringBuilder();
    sbJson.Append(oauth2.AccessTokenResponse);
    sbJson.WriteFile("qa_data/tokens/googleSheets.json","utf-8",false);

    // The saved JSON response looks like this:

    // 	{
    // 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
    // 	 "token_type": "Bearer",
    // 	 "expires_in": 3600,
    // 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
    // 	}
    // 
    console.log("OAuth2 authorization granted!");
    console.log("Access Token = " + oauth2.AccessToken);

}

chilkatExample();