# \#validation **URL:** https://community.auth0.com/tag/validation/431.md [Latest](https://community.auth0.com/latest.md) · [Categories](https://community.auth0.com/categories.md) · [Tags](https://community.auth0.com/tags.md) --- ## [How to add validations on the username/userid field on the login page](https://community.auth0.com/t/how-to-add-validations-on-the-username-userid-field-on-the-login-page/81616)
**Author:** [@shiny.lionel](https://community.auth0.com/u/shiny.lionel)\ **Replies:** 4\ **Last updated:** [April 21, 2022, 3:58am UTC](https://community.auth0.com/t/how-to-add-validations-on-the-username-userid-field-on-the-login-page/81616 "2022-04-21T03:58:28Z")
We would like to add validations on the username like length, if it can be alphanumeric etc on the login page. Please provide options/ APIs for the same. --- ## [How does validation url redirect work?](https://community.auth0.com/t/how-does-validation-url-redirect-work/8685)
**Author:** [@ben.runchey](https://community.auth0.com/u/ben.runchey)\ **Replies:** 1\ **Last updated:** [November 7, 2017, 4:04pm UTC](https://community.auth0.com/t/how-does-validation-url-redirect-work/8685 "2017-11-07T16:04:39Z")
Hello, I am just looking for some clarification about when a user receives the email verification link. I would like the user to land at my page rather than the auth0 page, is this what the URL redirect achieves? If s… --- ## [Access\_token invalid signature on jwt.io but not on the React.js tutorial](https://community.auth0.com/t/access-token-invalid-signature-on-jwt-io-but-not-on-the-react-js-tutorial/8545)
**Author:** [@zakiirjuman](https://community.auth0.com/u/zakiirjuman)\ **Replies:** 0\ **Last updated:** [October 22, 2017, 4:43am UTC](https://community.auth0.com/t/access-token-invalid-signature-on-jwt-io-but-not-on-the-react-js-tutorial/8545 "2017-10-22T04:43:00Z")
Hi, Part 3 of the React.js quick start tutorial sets you up with a server listening on :3001 and provides you with the React app code as well. It’s pretty much filled out and all I had to do was set the .env variables a… --- ## [How do I test "Trust Token Endpoint IP Header"?](https://community.auth0.com/t/how-do-i-test-trust-token-endpoint-ip-header/8031)
**Author:** [@basetech](https://community.auth0.com/u/basetech)\ **Replies:** 1\ **Last updated:** [August 31, 2017, 3:17pm UTC](https://community.auth0.com/t/how-do-i-test-trust-token-endpoint-ip-header/8031 "2017-08-31T15:17:06Z")
I implemented the “Trust Token Endpoint IP Header” flow in our application and was hoping to test it to validate that the IPs were coming through correctly. My first instinct was to check the logs, but it was still usin… --- ## [New Client but token validation fails in PHP SDK](https://community.auth0.com/t/new-client-but-token-validation-fails-in-php-sdk/6894)
**Author:** [@mike.norris](https://community.auth0.com/u/mike.norris)\ **Replies:** 1\ **Last updated:** [June 5, 2017, 10:31am UTC](https://community.auth0.com/t/new-client-but-token-validation-fails-in-php-sdk/6894 "2017-06-05T10:31:12Z")
We created a new Client for a new app. The angular frontend of the app successfully creates tokens and they validate on jwt.io. The PHP SDK in the backend API throws an Invalid Signature exception. Anyone else have this … --- ## [Issue with user information after updating Auth0 Java libraries](https://community.auth0.com/t/issue-with-user-information-after-updating-auth0-java-libraries/6764)
**Author:** [@anders.johansson](https://community.auth0.com/u/anders.johansson)\ **Replies:** 4\ **Last updated:** [June 2, 2017, 11:11am UTC](https://community.auth0.com/t/issue-with-user-information-after-updating-auth0-java-libraries/6764 "2017-06-02T11:11:58Z")
Hi there. i have been using auth0-spring-security-api, version: 0.3.2 together with auth0, version: 0.4.0 In my java backend i have been using the following lines of code to access the id\_token and call method to ac… --- ## [XAMARIN Quickstart error, Token Validation Errors](https://community.auth0.com/t/xamarin-quickstart-error-token-validation-errors/6673)
**Author:** [@nic.siggel](https://community.auth0.com/u/nic.siggel)\ **Replies:** 1\ **Last updated:** [May 22, 2017, 6:04am UTC](https://community.auth0.com/t/xamarin-quickstart-error-token-validation-errors/6673 "2017-05-22T06:04:43Z")
Hello, I am currently trying to get the XAMARIN quickstart working, namely for Android, however I keep getting the following error when looking at the login results: Error validating token response: Error validating id… --- ## [Having trouble with my node-Api validating my react client-side jwt-token](https://community.auth0.com/t/having-trouble-with-my-node-api-validating-my-react-client-side-jwt-token/6514)
**Author:** [@spencer.bigum](https://community.auth0.com/u/spencer.bigum)\ **Replies:** 3\ **Last updated:** [May 9, 2017, 11:31am UTC](https://community.auth0.com/t/having-trouble-with-my-node-api-validating-my-react-client-side-jwt-token/6514 "2017-05-09T11:31:06Z")
Hello Auth Community! I’ve just started using Auth0 and its really cool, but im running into some issues. My main issue is that I have a react client-side app that is saving the jwt token on user login - which is great…