The Ory Kratos SDK for JavaScript can get the session information in a React application using the

.toSession()

method without explicitly providing the Cookie value. This is possible when the application is browser-based, including single-page applications (SPAs) and server-side rendered apps. In this case, the session cookie is automatically sent with the request. The SDK configuration should have the

withCredentials: true

option set. Here is an example of how it can be done:

jsx import { Configuration, FrontendApi, Session } from "@ory/client"   import { useEffect, useState } from "react"      const frontend = new FrontendApi(     new Configuration({       basePath: "<http://localhost:4000>", // Use your local Ory Tunnel URL       baseOptions: {         withCredentials: true,       },     }),   )      export function checkSession() {     const [session, setSession] = useState<Session>(undefined)        useEffect(() => {       frontend         // the cookie is automatically sent with the request         .toSession()         .then(({ data: session }) => {           setSession(session)         })         .catch((error) => {           // The session could not be fetched           // This might occur if the current session has expired         })     }, [])        return session ? (       <table>         <tr>           <th>Session ID</th>           <th>Expires at</th>           <th>Authenticated at</th>         </tr>         <tr id={session.id}>           <td>{session.id}</td>           <td>{session.expires_at || ""}</td>           <td>{session.authenticated_at || ""}</td>         </tr>       </table>     ) : (       <div>Loading session data...</div>     )   }

In this example, the

withCredentials: true

option in the SDK configuration ensures that the session cookie is included in the request. The

.toSession()

method then retrieves the session information. For more details, you can refer to the [Ory documentation](https://www.ory.sh/docs/kratos/session-management/overview#using-ory-session-cookie).

The

withCredentials

property is a part of the XMLHttpRequest and Fetch APIs in web development, and it's used to include cookies in cross-origin requests. When

withCredentials

is set to

true

, it tells the browser to expose the response to frontend JavaScript code when the request's credentials mode (

Request.credentials

) is

include

. When making AJAX requests, setting

withCredentials: true

allows HTTP cookies to be sent along with the request, even when the request is to a different domain. This is important for maintaining sessions and passing along credentials in cross-origin requests. Here's an example of how it's used with the Fetch API:

javascript fetch(url, { credentials: "include" })

And here's an example of how it's used with the XMLHttpRequest API:

javascript var xhr = new XMLHttpRequest(); xhr.open('GET', '<http://example.com/>', true); xhr.withCredentials = true; xhr.send(null);

In the context of Ory,

withCredentials: true

is used in the SDK configuration to automatically include the session cookies in the request when calling the

.toSession()

method. Please note that for

withCredentials

to work, the server must also allow credentials from the client's origin by setting the

Access-Control-Allow-Credentials

header to

true

and specifying the client's origin in the

Access-Control-Allow-Origin

header. For more details, you can refer to the [MDN Web Docs](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#requests_with_credentials).

To replicate the behavior of the Ory Kratos JavaScript SDK using HTTP requests and JavaScript code to check if a session exists, you can use the Fetch API or XMLHttpRequest API to make a GET request to the

/sessions/whoami

endpoint. Here are the steps: 1. Set up the URL for the

/sessions/whoami

endpoint. This will be your Ory Kratos server's URL followed by

/sessions/whoami

. 2. Make a GET request to the

/sessions/whoami

endpoint. Include the

credentials: 'include'

option to automatically send cookies with the request. Here's an example using the Fetch API:

javascript const url = '<http://localhost:4000/sessions/whoami>'; // Replace with your Ory Kratos server URL  fetch(url, {   method: 'GET',   credentials: 'include', }) .then(response => response.json()) .then(data => console.log(data)) .catch((error) => {   console.error('Error:', error); });

In this example, replace

'<http://localhost:4000/sessions/whoami>'

with your actual Ory Kratos server URL. The

credentials: 'include'

option ensures that cookies are sent with the request, similar to setting

withCredentials: true

in the Ory Kratos JavaScript SDK. If the user has an active session, the server will return a

200 OK

response with the session payload. If the user doesn't have an active session, the server will return a

401 Unauthorized

response. For more details, you can refer to the [Ory documentation](https://www.ory.sh/docs/kratos/reference/api#operation/toSession).

You can run this JavaScript code in a web browser environment, such as in a script tag in an HTML file or in a JavaScript file that's linked to an HTML file. Here's an example of how you can use it in an HTML file:

html <!DOCTYPE html> <html> <body>     <script>         const url = '<http://localhost:4000/sessions/whoami>'; // Replace with your Ory Kratos server URL          fetch(url, {             method: 'GET',             credentials: 'include',         })         .then(response => response.json())         .then(data => console.log(data))         .catch((error) => {             console.error('Error:', error);         });     </script> </body> </html>

In this example, replace

'<http://localhost:4000/sessions/whoami>'

with your actual Ory Kratos server URL. To run this HTML file: 1. Save the file with a

.html

extension, such as

check-session.html

. 2. Open the file in a web browser. You can do this by double-clicking the file in your file explorer or by entering the file's path in your web browser's address bar (for example,

file:///path/to/check-session.html

). When you open the HTML file in a web browser, the JavaScript code will automatically run and the result will be logged to the browser's console. You can view the console by right-clicking on the webpage, selecting "Inspect" or "Inspect Element", and then going to the "Console" tab. Please note that for security reasons, some browsers may block fetch requests from local files. In this case, you may need to run the HTML file from a local server or use it in the context of a larger web application.

I'm sorry to hear that you're having trouble. The

.toSession()

method is part of the Ory Kratos JavaScript SDK. You can find the source code for the SDK on the [Ory Kratos GitHub repository](https://github.com/ory/kratos). However, the exact implementation of the

.toSession()

method might not be directly viewable as it could be part of the compiled code. The SDK is generated from the Ory Kratos API specification using OpenAPI Generator, which means the actual function implementation is created automatically based on the API definition. If you're having issues with the

.toSession()

method or the Ory Kratos JavaScript SDK, I would recommend checking the [Ory Kratos documentation](https://www.ory.sh/docs/kratos/) or asking for help in the [Ory Community Chat](https://slack.ory.sh/) or [GitHub discussions](https://github.com/discussions?discussions_q=org%3Aory).