We have a client with a Mikrotik Hotspot onsite and a remote Mikrotik User Manager that authenticates users.

What they want is a 30 minute voucher, that if expired, brings a pop up/ or redirects their browser - this takes them to a survey. If the user completes the survey they have their time extended by another 30minutes (or possibly issue them with new login details with 30 minutes available), however this pop-up or redirected page must only be available once per voucher. (and not available to the vouchers generated after the survey – if that route is taken).

If someone has done something similar or is willing to do the programming I am willing to pay for the customization.

Please email me if you are willing to take something like this on.

We have a client with a Mikrotik Hotspot onsite and a remote Mikrotik User Manager that authenticates users.
What they want is a 30 minute voucher, that if expired, brings a pop up/ or redirects their browser - this takes them to a survey. If the user completes the survey they have their time extended by another 30minutes (or possibly issue them with new login details with 30 minutes available), however this pop-up or redirected page must only be available once per voucher. (and not available to the vouchers generated after the survey – if that route is taken).
If someone has done something similar or is willing to do the programming I am willing to pay for the customization.
Please email me if you are willing to take something like this on.

I don't think it's possible With Mikrotik.
Maybe you have to use 3rd party customized Radius Billing Server for this purpose.
In the past ,Using Radius Manager, I created timed vouchers (1 hour limit), after 1 hour when there accounts expires, they were redirected to my local intranet website with the suggestion forum.

aacable is correct. It will require a lot of back-end modification and customization to get what you want. It's not going to be easy or cheap to really do.

1.) For the 30 minute limit for a code: You will need to program the database that Radius uses to check if the access code is valid/correct to deactivate the code on a successful login. This most likely means using a SQL database and a different Radius server, as well as custom programing to accomplish that task.
2.) For the survey requirement, that will require a custom remote login page most likely. You could potentially modify the payment reminder script to fit your needs, but I'm thinking a more reliable solution would be to use cookies to control what an end user sees. So the first time they pull up the login page they get your standard form and a cookie that lasts for lets say 1 hour. After 30 minutes they are logged off by a session timeout and the next page they go to will bring up the login page again, except this time the page will see that the user has a valid cookie from 30 minutes ago, and displays the survey instead.

It will require a lot of back-end modification and customization to get what you want. It's not going to be easy or cheap to really do.

I realize that and indicated to the client. He still wants some kind of ballpark figure though.

2.) For the survey requirement, that will require a custom remote login page most likely. You could potentially modify the payment reminder script to fit your needs, but I'm thinking a more reliable solution would be to use cookies to control what an end user sees. So the first time they pull up the login page they get your standard form and a cookie that lasts for lets say 1 hour. After 30 minutes they are logged off by a session timeout and the next page they go to will bring up the login page again, except this time the page will see that the user has a valid cookie from 30 minutes ago, and displays the survey instead.

Great idea