Store referral code for later during signup (for later retreival)?

[shea]

I want to store a referral field when a user signs up.

• When we send a referral email to a user, it contains a link directs them to our univeral login signup page.
• After a user signs up, the are directed to a page that tells them to check their inbox and verify their email.
• Upon verifying their email, they are redirected to our account setup page, which contains the referral code field.
• I would like to pre-populate this referral code.
• I tried putting the code as a query param for the redirect_uri. But this doesn’t work because at the time of the redirect, the user has not verified their email yet.

I am directing the users to:
https://my-tenant.auth0.com/authorize?response_type=code&screen_hint=signup&client_id=my-client-id&redirect_uri=https://myapp.com/verify-email-page&referralCode=rf-123-456-789

In the onExecutePreUserRegistration event, I could store the code in the meta data. But I am not sure where to grab the code from. The following doesn’t seem to work, as referralCode seems to be undefined.

exports.onExecutePreUserRegistration = async (event, api) => {
  const referralCode = event.request['referralCode'];
  if(referralCode) {
    api.user.setAppMetadata('referral_code', referralCode);
  }
};

EDIT:
I don’t seem to be able to make this work using my custom query parameter. But if I hijack the state variable, I can pull the code from there. Is that bad?

In otherwords, I redirect the user to https://my-tenant.auth0.com/authorize?response_type=code&screen_hint=signup&client_id=my-client-id&redirect_uri=https://myapp.com/verify-email-page&state=rf-123-456-789.

exports.onExecutePreUserRegistration = async (event, api) => {
  const referralCode = event.transaction?.state;
  console.log(`referral_code='${referralCode}'`);
  if(referralCode) {
    api.user.setAppMetadata('referral_code', referralCode);
  }
};

EDIT2:
The above only seems to work on the test run when editing the application. When I do an actual login, for some reason event.transaction?.state is undefined. Even though in the logs it shows that the state does exist:

{
    "actions": {
      "executions": [
        "jqj1Xa_7TK-VOYv8idJ722jIwMjMxMTI0"
      ]
    },
    "body": {
      "connection": "Username-Password-Authentication",
      "client_id": "asdfasdfasdfasdfas",
      "email": "someguy@domain.com",
      "password": "*****",
      "is_signup": true,
      "tenant": "test-tenant",
      "transaction": {
        "id": "dZYS-jK0ldnD5WS7Yk3kxM8TmgxyVd-PC",
        "locale": "en",
        "protocol": "oidc-basic-profile",
        "requested_scopes": [],
        "acr_values": [],
        "ui_locales": [],
        "redirect_uri": "https://my-application.com/new-account",
        "prompt": [],
        "state": "test-referral-code-8888",
        "login_hint": null,
        "response_mode": null,
        "response_type": [
          "code"
        ]
      },
      "form": {},
      "request_language": "en-US,en;q=0.9"
    },
    "authentication_methods": [
      "pwd"
    ]
  }

Why is the state undefined in my event handler?

[dan.woda]

Hi @shea,

It’s not possible to send a param with the request to signup and retrieve it in a pre reg action. More info here. Even more info here.

Hijacking the state could be a security risk. I can’t suggest that strategy either.

This may be something you want to handle in the background before sending the user to the registration page.

Hope this helps!