JWT-based authentication

You can connect Metabase to your identity provider using JSON Web Tokens (JWT) to authenticate people.

Authentication flows

Metabase supports two auth flows that can be used with JWT:

• Authorization Code Flow
• Authorization Code Flow with PKCE

Metabase’s auth flows are custom workflows modelled after OAuth 2.0. You can use the auth flow with PKCE to incorporate random keys generated on demand.

Currently, the only algorithm Metabase supports is HS256 (HMAC + SHA-256).

Typical flow for a JWT-based SSO interaction with Metabase

Assuming your site is localhost serving on port 3000:

1. Person attempts to view a question, e.g., http://localhost:3000/question/1-superb-question.
2. If the person isn’t logged in, Metabase redirects them to http://localhost:3000/auth/sso.
3. Retaining the original /question/1-superb-question URI, Metabase redirects the person to the SSO provider (the authentication app).
4. Person logs in using the basic form.
5. In the event of a successful sign-in, your authentication app should issue a GET request to your Metabase endpoint with the token and the “return to” URI: http://localhost:3000/auth/sso?jwt=TOKEN_GOES_HERE&return_to=/question/1-superb-question.
6. Metabase verifies the JSON Web Token, logs the person in, then redirects the person to their original destination, /question/1-superb-question.

Enabling JWT authentication

Navigate to the Admin>Settings section of the Admin area, then click on the Authentication tab. Click the Configure button in the JWT section of this page, and you’ll see this form:

Here’s a breakdown of each of the settings:

JWT Identity Provider URI: This is where Metabase will redirect login requests. That is, it’s where your users go to log in through your identity provider.

String Used by the JWT Signing Key: The string used to seed the private key used to validate JWT messages. Both Metabase and the authentication app should have the same JWT signing key.

User attribute configuration (optional)

These are additional settings you can fill in to pass user attributes to Metabase.

• Email attribute: the key to retrieve each JWT user’s email address.
• First Name attribute: the key to retrieve each JWT user’s first name.
• Last Name attribute: if you guessed that this is the key to retrieve each JWT user’s last name, well then you have been paying attention.

You can send additional user attributes to Metabase by adding the attributes as key/value pairs to your JWT. These attributes will be synced on every login.

Configure group mappings

You can use your JWT to assign Metabase users to custom groups.

1. Add groups to your JWT: groups: ["group_name"].
2. In Metabase, go to the Admin panel and switch to Setting > Authentication tab.
3. Click the Configure button under JWT.
4. Under Group Schema, turn on the toggle Synchronize Group Memberships
5. Click New mapping and add the name of a JWT group.
6. In the row that appears, click the dropdown to pick the Metabase group(s) that this should map to.
7. Repeat this for each of the groups you want to map.

Alternatively, you can define the mappings between JWT and Metabase groups using the environment variable MB_JWT_GROUP_MAPPINGS. It accepts a JSON object where the keys are JWT groups and the values are lists of Metabase groups IDs. For example:

MB_JWT_GROUP_MAPPINGS='{"extHR":[7], "extSales":[3,4]}'

where extHR, extSales are names of JWT groups and 3,4,7 are IDs of Metabase groups.

You can find Metabase Group ID in the URL for the group page, like http://your-metabase-url/admin/people/groups/<ID>. “All Users” group has ID 1 and “Administrators” group has ID 2.

You can also use the environment variable MB_JWT_GROUP_SYNC to turn group sync on or off.

MB_JWT_GROUP_SYNC=true

Creating Metabase accounts with SSO

Paid plans charge for each additional account.

A new SSO login will automatically create a new Metabase account.

Metabase accounts created with an external identity provider login don’t have passwords. People who sign up for Metabase using an IdP must continue to use the IdP to log into Metabase.

Disabling password logins

Avoid locking yourself out of your Metabase! This setting will apply to all Metabase accounts, including your Metabase admin account. We recommend that you keep password authentication enabled. This will safeguard you from getting locked out of Metabase in case of any problems with SSO.

To require people to log in with SSO, disable password authentication from Admin settings > Authentication.

Note about Azure

If you’re using Azure, you may need to use Azure AD B2C. Check out their tokens overview.

Example code using JWT-based authentication

You can find example code that uses JWT authentication in the SSO examples repository.

• JWT example in a Clojure app
• JWT example in JavaScript (Node) app