Custom Rating / Pricing Functions — User-supplied code or formulas that compute charges the standard catalog cannot express — bespoke tiering, multi-dimensional rates, negotiated exceptions. These functions run inside the rating step, so mediation feeds them clean usage and invoicing consumes their output unchanged.
Custom Rating / Pricing Functions lives in the Platform & Intelligence phase of Grow Revenue — the stage where you retain, expand, and compound revenue on the platform. In the corpus tool index this phase maps to the Analytics and Data platform and Cost & FinOpscategories.
No product category maps cleanly onto this module yet — companies typically build it in-house or cover it with adjacent tooling. See who builds vs buys across the corpus.