The issue you're experiencing could be due to a few reasons: 1. The token has expired or has been revoked. The introspection endpoint checks if a token (both refresh and access) is active or not. An active token is neither expired nor revoked. If a token is active, additional information on the token will be included. If it's not active, it will return 'active: false' and all other fields as null. [source](https://www.ory.sh/docs/hydra/reference/api) 2. The token was not properly issued or there was an error during the token issuance process. You can check the logs for any errors during the token issuance process. 3. The token is not recognized by the system. This could happen if the token was issued by a different system or if there was a system error. To debug this issue, you can use the

/oauth2/token

endpoint to check the validity of the token. If the token is invalid, the endpoint will return an error message. If you need more information for debugging, you can switch the project to development mode to see the

error_debug

field in the response. [source](https://www.ory.sh/docs/hydra/debug#oauth2token-endpoint-fails-for-jwks-based-client) If you're still having issues, you might want to check the implementation of your token introspection function. Here's a sample implementation using the Hydra SDK:

javascript import { Configuration, OAuth2Api } from "@ory/client"      const ory = new OAuth2Api(    new Configuration({    basePath: `https://${process.env.ORY_PROJECT_SLUG}.<http://projects.oryapis.com|projects.oryapis.com>`,    accessToken: process.env.ORY_API_KEY,    }),   )      export async function introspectToken(accessToken: string) {    const { data } = await ory.introspectOAuth2Token({ token: accessToken })    data.active // true or false   }

[source](https://www.ory.sh/docs/hydra/guides/oauth2-token-introspection)