Afunana — Legacy Code Intelligence for IBM i

Afunana brings AI-powered documentation for your IBM i (AS/400) legacy systems directly into VS Code. Open any COBOL, RPG, or CL source file and instantly see what the program does, what files it uses, what business rules it enforces, and what breaks if you change it — without leaving your editor.

Features

Auto-loading program documentation
Switch to any .cbl, .rpg, .clp, or .mbr file and the sidebar panel automatically loads the program's full documentation from your Afunana collection — purpose, business rules, data inputs/outputs, dependencies, and criticality level.

File documentation on hover
Hover over a file name in COBOL ASSIGN statements or CLP FILE() parameters to see the file's business description, field list, key fields, and which programs use it.

In-editor chat
Ask natural language questions about any program or the system as a whole directly from the sidebar — powered by Afunana's RAG pipeline.

Field lookup
Look up any field to see which files contain it and how many programs use it.

Clickable dependency navigation
Click any program or file name in the sidebar to navigate to its documentation instantly.

Requirements

An active Afunana account and a built collection. Sign up at afunana.io.

Getting Started

1. Install the extension
2. Run Afunana: Login from the Command Palette
3. Open any IBM i source file — documentation loads automatically

Supported File Types

COBOL (.cbl, .cob), RPG (.rpg, .rpgle), CL (.clp, .cl), DDS (.dds, .pf, .lf), and memberless files (.mbr)