An AI rewrites an RPG or RPGLE program on your IBM i. It builds, the green-screen flows still work, and it writes the code the way modern examples do, not the way your shop has done it for thirty years. The mid-market ERP, manufacturing, and distribution systems that run on RPG are full of conventions that were never written down, and the developers who held them are retiring.
Step one · the map
doloop reads your RPG call structure, the CALL and CALLP statements and the bound procedures, and makes the system navigable. You get the load-bearing programs and service programs a change ripples out from, the file and data layer, a triage list of programs the static call graph never reaches, and the strata that show fixed-format RPG IV alongside the later free-format code. It shows where the system is structured, not what it computes. The scan is free, and it reads none of your business logic.
Programs reached only through a dynamic CALL or job setup show up as leads to review, not as a verdict that the code is dead.
Step two · the gate
Once the system is navigable, doloop gates the changes. Where your RPG keeps a convention, it infers that convention from your own code and flags an AI rewrite that breaks it, deterministically, with the rule, the line, and the rate behind every flag. RPG shops vary, so the first scan measures, on your own code, where your conventions run tight enough for the gate to enforce, and runs the gate there.
The method reads a system's own conventions in any language. It works on code as different as modern Python and COBOL systems up to forty years old, where 525 of 525 held-out programs passed leave-one-out, verified three independent ways. Your RPG estate is next, read on your own code.
Your source never leaves your machine. Bring your own model. Request your first scan →
Routes you to a real doloop page, asks when your question is ambiguous, or tells you when there is no answer. No model runs on the answer path, so it cannot invent one.