--- title: About session tokens description: Learn about session tokens and how they fit into the authentication flow for a Shopify app. source_url: html: https://shopify.dev/docs/apps/build/authentication-authorization/session-tokens/index md: https://shopify.dev/docs/apps/build/authentication-authorization/session-tokens/index.md --- # About session tokens A session token is a mechanism that lets your app authenticate the requests that it makes between the client side and your app's backend. **Note:** All apps rendered in the Shopify admin need to use session tokens because third-party cookies won't work with browsers that restrict cross-domain data access. If your app still uses cookies and could pose a risk to users, then as part of our [app quality check process](https://shopify.dev/docs/apps/launch/app-store-review/app-quality-checks) you might be contacted and requested to migrate your app to use session tokens. This request will require immediate action. The following video provides a short introduction to session tokens: *** ## How session tokens work This section describes the authentication and request flows associated with session tokens, and the lifetime of a session token. It also provides information about implementing both OAuth and session token authentication for apps. ### Authentication flow using a session token When your app first loads, it's unauthenticated and serves up the frontend code for your app. Your app renders a user interface skeleton or loading screen to the user. After the frontend code has loaded, your app calls a [Shopify App Bridge action](https://shopify.dev/docs/api/app-bridge/previous-versions/actions) to get the session token. Your app includes the session token in an authorization header when it makes any HTTPS requests to its backend. ![](https://shopify-assets.shopifycdn.com/shopifycloud/shopify-dev/production/assets/assets/images/partners/jwt-auth-flow-DC23sv78.png) ### Request flow using a session token The session token is signed using the shared secret between your app and Shopify so that your backend can verify if the request is valid. ![](https://shopify-assets.shopifycdn.com/shopifycloud/shopify-dev/production/assets/assets/images/apps/auth/jwt-request-flow-DDQ5Q8bW.png) ### Lifetime of a session token The lifetime of a session token is one minute. Session tokens must be fetched using Shopify App Bridge on each request to make sure that stale tokens aren't used. ### OAuth and session tokens **Tip:** You can use [Shopify CLI](https://shopify.dev/docs/apps/build/cli-for-apps) to generate a starter app with boilerplate code that handles authentication and authorization. The starter app includes code for an app rendered in the Shopify admin that uses [session tokens](https://shopify.dev/docs/apps/build/authentication-authorization/session-tokens) and [token exchange](https://shopify.dev/docs/apps/build/authentication-authorization/access-tokens/token-exchange). Session tokens are for authentication, and aren't a replacement for [authorization](https://shopify.dev/docs/apps/build/authentication-authorization#authorization). Learn more about the [difference between authentication and authorization](https://shopify.dev/docs/apps/build/authentication-authorization#authentication-vs-authorization). Unlike API access tokens, session tokens can't be used to make authenticated requests to Shopify APIs. An API access token is what you use to send requests from your app's backend to Shopify so that you can fetch specific data from the user's shop. For example, to [make authenticated requests](https://shopify.dev/docs/apps/build/authentication-authorization/access-tokens/token-exchange#step-3-make-authenticated-requests) to the [GraphQL Admin API](https://shopify.dev/docs/api/admin-graphql), your app must store the access token it receives during the OAuth flow. To contrast, session tokens are used by your app's backend to verify the embedded request coming from your app's frontend. The following diagram shows the authentication process using session tokens and API access tokens: ![Diagram showing authentication process using sessions tokens and API access tokens](https://shopify-assets.shopifycdn.com/shopifycloud/shopify-dev/production/assets/assets/images/partners/auth-mechanisms-4HBrY0T6.png) *** ## Anatomy of a session token Session tokens use the [JSON Web Token (JWT)](https://jwt.io) format and contain information about the merchant that's currently using your app. A session token consists of a header, payload, and signature. For an interactive example, refer to [JWT.io](https://jwt.io/), where you can experiment with setting different values for each section. Shopify recommends that you use your test app's credentials when testing on JWT.io. For the most part, you shouldn't have to manage the anatomical details of session tokens. In most scenarios, you'll use a library, such as `authenticated_fetch` from [app-bridge](https://www.npmjs.com/package/@shopify/app-bridge), which generates and includes the session token in your requests. On the backend, you can use middleware similar to `validateAuthenticatedSession` in [@shopify/shopify-app-express](https://github.com/Shopify/shopify-app-js/blob/main/packages/apps/shopify-app-express/docs/reference/validateAuthenticatedSession.md). After a Shopify session token is decoded, it has the following fields: ### Header The values in the header are constant and never change. ```json { "alg": "HS256", "typ": "JWT" } ``` * `alg`: The algorithm used to encode the JWT. * `typ`: The [(type) header parameter](https://tools.ietf.org/html/rfc7519#section-5.1) used by session token to declare the media type. ### Payload ```json { "iss": "", "dest": "", "aud": "", "sub": "", "exp": "