Hello everybody:

We are trying to integrate Salesforce with an external web app which means we need to authenticate Salesforce against this external app. This external app uses SAML as part of its security locks.

We need to perform this authentication on demand by clicking a Visualforce page or a page layout button and then we should be able to handle the response and if the authentication is correct then we need to invoke some API call using an external API (once we are fully authenticated)

I have been researching and i haven't found any example, guide or similar that fits my scenario. What i have find is about SSO and SAML but i think that is not my case because SSO with SAML is only to allow users to log in to Salesforce using, for example, their intranet logins.

I have experience in apex and Visualforce but i have no  experience with SAML, so any link, advice, code snippet or explanation will be much appreciated.

Anybody that have more experience with SAML?

Thanks in advance.