Custom login screen for Appian Cloud

We have not done anything like this already, but short of developing and hosting your own form with custom code (PHP, Ruby etc.), you could use something like FormStack or Wufoo to host your form and integrate via Web Services to trigger a registration process. These 3rd party tools include captcha (robot) checking. However I'm not sure how you could handle validation of already existing logins.

Hi Gary,
Are you looking a way to set up a process for New User Onboarding?
Do you want to integrate the Login screen with Appian to create the user directly?
You can do it by creating the process model(for creating the user provided with some details) and exposing it as a web service and calling it from the UI you create(You can create a simple UI using Java or any technology you like).
Security Question validation is not present in Appian User creation.
You can check whether the User ID itself is existing or not.

But do you want to expose this UI to all the users in an organization or to a specific users?

@garym - You can create a registration form in html and get it hosted.Then you can create a process model which takes in all the inputs fetched from the registration form and publish it as a web service. Then on click of submission of the registration form you can trigger this process model and use the following shared components.

Captcha - https://forum.appian.com/suite/tempo/records/item/lMBCLGOdlMUpdGVqW3dQaIKmclBmvvNEj8vu_cjb7T-5YiPr4Fu8ly5Yj1s09uenE4RYzA8zKyx7eiUh-mvLnNz7pWaADqvf87Q9fmzA6MWEu8g7g/view/summary
Personalization Utilities(creating users specifying the i18n preferences and it verifies whether an username is available to create a new account) - https://forum.appian.com/suite/tempo/records/item/lIBCLGOdlMUpdGVqW3dQaIKmclBmvvNEj8vu_cjb7T-5YiPr4Fu8ly5Yj1s09uenE4RYzA8zKyx7eiUhetE6R7wweiOH6ioZIxyCYszpaPoTE8_/view/summary
For checking whether the username already exists you can write a web api which checks whether the username exists or not (using isusernametaken()) and will return the response accordingly.
Check shared components for other.

And if you are on 16.2 then you can create Web API(s) and call OOTB smart service functions instead of creating process models and publishing it.
Of course both their own advantages which you can choose according to your requirements.

Other options would be to use your IDP login page (assuming you are not using Appian authentication), or to create a custom servlet plugin which handles the registration, and add a register link on the login page. Feel free to open a Support ticket to discuss these options further.

Thanks everyone for your responses...much appreciated
@sanjays - Yes, it is a New User Onboarding. We use our Active Directory for authentication. Can I actually create a user in our AD via this web service? The UI will be exposed to the outside world since it can potentially be anyone that would be interested in registering in our system

@sidhantb - I will definitely look into those forum links you mentioned. Same question as above. Does it complicate matters that we use our AD for authentication? Can this user creation actually create an account in our Active Directory?

@Tom Ryan - What is IDP?

Is it possible in any way that the new user be directly redirected to an Appian form/interface/landingpage as soon as he completes the registration successfully ? How does the user get logged-in to Appian system automatically for him to be able to view that interface without providing credentials again through Appian login page ?

Gary,
Are you asking Onboarding setup for Appian or Onboarding setup for the AD?

IDP = Identity Provider, which is your AD in this case

@sanjays - Onboarding setup for AD

@Tom Ryan - Is there anything available for security questions during onboarding and to be used when a password is forgotten?