ActionController::InvalidAuthenticityToken rails when submitting form

  1. The ActionController::InvalidAuthenticityToken error is raised when submitting a form in Ruby on Rails.

  2. This error occurs when Rails detects that the authenticity token, which is a security feature used to prevent cross-site request forgery (CSRF) attacks, is missing or invalid.

  3. CSRF attacks occur when an attacker tricks a user into performing actions on a website without their consent. This can be done by tricking the user into clicking on a malicious link or submitting a form without their knowledge.

  4. To protect against CSRF attacks, Rails generates an authenticity token for each form. This token is included as a hidden field in the form and is also stored in the user's session.

  5. When the form is submitted, Rails checks if the authenticity token in the form matches the one stored in the session. If they don't match, the ActionController::InvalidAuthenticityToken error is raised.

  6. This error typically occurs when there is a problem with the form submission process, such as a missing or tampered authenticity token.

  7. To fix this error, you can try the following steps:

a. Make sure that your form includes the <%= csrf_meta_tags %> tag in the head section of your layout file. This tag adds the authenticity token to the page's meta tags.

b. Check if you have included the <%= csrf_token %> tag in your form. This tag inserts a hidden field with the authenticity token.

c. Ensure that you are not accidentally modifying or removing the authenticity token value in your JavaScript code or any other custom code.

d. Check if your form submission is being intercepted by any middleware or plugins that might be modifying the form data or the authenticity token.

e. If you are using AJAX to submit the form, make sure that you are including the authenticity token in the request headers or as a request parameter.

  1. By following these steps, you should be able to resolve the ActionController::InvalidAuthenticityToken error and successfully submit your form without any issues.