What is Nomain?

Nomain reads your software, from decades-old mainframe COBOL, PL/I, JCL and CICS to modern languages, and turns it into a living model of each system that you can explore visually, navigate, and ask questions about in plain language.

Instead of reading through every program, copybook and job definition by hand, you point Nomain at your code. It parses everything, works out how the pieces connect, reconstructs the business processes the code carries out, writes plain-language explanations of each part, and makes the whole thing searchable. From there you can chat with it, walk the connections on an interactive map, and read end-to-end business flows as clean diagrams.

Who it is for

• Developers and architects who need to understand a large or unfamiliar codebase quickly: what calls what, where a change ripples, and what a program actually does.
• Teams maintaining or modernizing long-lived systems, especially mainframe estates where the original authors and documentation are long gone.
• Business and delivery people who want to see, in business terms, what a system does across its domains, areas and processes, without reading code.

The core idea: a System

Everything in Nomain revolves around a System. A System is Nomain's structured model of one of your software systems, built automatically from its source code, jobs, copybooks and any documents you attach.

   Your code repositories                              What you work with
   ──────────────────────                              ──────────────────
   COBOL · PL/I · JCL · CICS/BMS                        ┌────────────────────┐
   copybooks · DB2/DDL · schedulers   ──▶  Nomain ──▶   │      A System      │
   C#/.NET · JavaScript/TypeScript                      │ (explorable model) │
   + your own documents                                 └────────────────────┘
                                                          │  Chat · Graph map
                                                          │  Business processes
                                                          │  Explanations · Search

Once a System exists you can:

• Chat with it: ask questions and get answers grounded in the real code, with clickable evidence.
• Explore its map: an interactive graph of programs, jobs and data, and how they connect.
• Read its business processes: the workflows the software carries out, as step-by-step diagrams grouped by business domain.

New name, same thing

If you have used Nomain before, you may remember the term Knowledge Graph. That concept is now called a System throughout the product. You will still see /graphs in some web addresses, but everywhere in the interface it is a System.

How the documentation is organized

Section	What you'll find
Getting started	The core ideas in five minutes, and a tour of the app.
Core concepts	Systems, repositories & sources, business domains & processes, and agent memory.
Using Nomain	Chat, the graph visualization, usage insights, and the VS Code extension.
Administration	For tenant admins: managing users, single sign-on, running analysis, and document management.
Reference	A glossary and the list of supported languages and source types.

A note on accuracy

Nomain's answers and explanations are generated by AI. They are grounded in your actual code and cite their evidence, but you should still review them for accuracy before acting on anything important. The product shows this reminder wherever the assistant answers: "AI can make mistakes. Review answers for accuracy."