
EricP.72813 (Customer) asked a question.
I see in the Access Gateway templates that we can connect to legacy applications using things like Kerberos, or custom Headers-based auth, and there are a number of specific integrations mostly using various Oracle-type authentication schemes. But I don't see any obvious way to use Access Gateway to proxy to an internal SAML application. Is this possible? How?

Okta Access Gateway is designed for legacy Header Based applicatios.for OAG to use, Okta act as the IDP. I think You can proxy any type of application as give in the documentation of OAG.
https://help.okta.com/en/prod/Content/Topics/Access-Gateway/add-sample-proxy-app-okta.htm
May I know why do you want to Proxy a SAML application?
Same reason we'd want to proxy any other application: it's on-prem and we don't want to expose it directly to the Internet. Whether it's header-based, Kerberos, or SAML should be irrelevant. I would expect to be able to use OAG as a single point of entry to everything we have on-prem.