> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## POST support for JWT callback security The JWT callback endpoint (`/api/fern-docs/auth/jwt/callback`) now accepts `POST` requests with `application/x-www-form-urlencoded` body in addition to `GET` requests with query parameters. POST avoids exposing JWT tokens in URLs and server logs. Read the docs