Decision Management (ODM,ADS)

Is it possible to have a link in a local application to the Decision center using the userid/password in the URL or in the header?

I'll let you decide if this is a safe thing to do from a security perspective but this old trick still seems to work for the latest version of ODM on a local install:
http://localhost:9090/decisioncenter/j_security_check?j_username=odmAdmin&j_password=odmAdmin

This probably won't work for a containerised or SaaS version of ODM. I use the basic RPA capabilities of a password manager tool to automate the authentication of a SaaS version of ODM because it requires re-authentication every few hours.

It doesn't seem secure to put a link in a webapp that makes appear a clear password, even encoded using basic authentication.

But, if your scenario is to provide an authenticated/authorized access to Decision Center inside a third party web app, it's preferable to use OpenId. Then, you can put any link to access Decision Center inside this webapp that already contains the access/id token of the current web session and that will be shared by any application configured with the same OpenId provider.

By hoping it can fits your use case.