---
title: Enhance Transform Rules with JWT claims · Cloudflare API Shield docs
description: You can forward information from a JSON Web Token (JWT) to the origin in a header by creating Transform Rules using claims that Cloudflare has verified via the JSON Web Token.
lastUpdated: 2025-03-17T19:33:42.000Z
source_url:
  html: https://77261bbd.preview.developers.cloudflare.com/api-shield/security/jwt-validation/transform-rules/index.md
  md: https://77261bbd.preview.developers.cloudflare.com/api-shield/security/jwt-validation/transform-rules/
---

You can forward information from a [JSON Web Token (JWT)](https://developers.cloudflare.com/api-shield/security/jwt-validation/) to the origin in a header by creating [Transform Rules](https://developers.cloudflare.com/rules/transform/) using claims that Cloudflare has verified via the JSON Web Token.

Claims are available through the `http.request.jwt.claims` firewall fields.

For example, the following expression will extract the user claim from a token processed by the token configuration with `TOKEN_CONFIGURATION_ID`:

```txt
lookup_json_string(http.request.jwt.claims["<TOKEN_CONFIGURATION_ID>"][0], "claim_name")
```

Refer to [Configure JWT validation](https://developers.cloudflare.com/api-shield/security/jwt-validation/configure/) for more information about creating a token configuration.

## Create a Transform Rule

As an example, to send the `x-send-jwt-claim-user` request header to the origin, you must create a Transform Rule:

1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com/) and select your account and domain.
2. Go to **Rules** > **Overview**.
3. Next to **Request Header Transform Rules**, select **Create rule**.
4. Enter a rule name and a filter expression, if applicable.
5. Choose **Set dynamic**.
6. Set the header name to `x-send-jwt-claim-user`.
7. Set the value to `lookup_json_string(http.request.jwt.claims["<TOKEN_CONFIGURATION_ID>"][0], "claim_name")`, where `<TOKEN_CONFIGURATION_ID>` is your token configuration ID found in JWT validation and `claim_name` is the JWT claim you want to add to the header.
