How to access a Appian pages from a SAP CRM Portal seamlessly?

We are on cloud environment and SAP CRM portal will be hosted on organization intranet

Might be embedded interfaces fulfills your requirement, For more info have a look on this link docs.appian.com/.../Embedded_Interfaces.html

Few options (while still meeting your seamless requirement):

1) Embedded SAIL. But 1 problem would be how to move the data generated into this SAIL form. Say, if the user is selecting few employees in your SAP portal and if this is the data you want to send across to Appian, then the first problem would be how to populate this data into the Embedded UI so that it is into Appian. AFAIK, this would involve duplicating/moving some amount of data generation into Appian.

2) Populate data into a database shared by both systems and if feasible make it retrievable by just the user id (+ timestamp + isActive flag). In this case, through SSO, the user can land in Appian and Appian could then pull data from DB based on just the loggedInUser id.

3) A Hybrid option - populate data into a shared DB and create entity record. Use this record identifier to take the user directly into the Record via Embedded Interface. User can then take actions using Related Actions.

Thank you