Source code & finding your way in a project
No src, no node_modules
Alice asked an AI for a small booking tool. The folder had no src and no node_modules — only app.py, templates, and a .venv she was told never to open. She hunted for page.tsx, found none, and froze. Her cousin said: start from the words on the screen; folder names change, the jobs do not. Alice still did not know which three folders were hers.
- Source code is plain text in ordinary files. You can open and read any of it.
- Endings name the kind: .js/.ts, .py, .cs, .css, .html — plus .json/.yaml/.md for settings and notes.
- Your folders may be app/, src/, or the project root — not every app has src/ or node_modules/.
- Find a feature by searching for the words on screen, then follow it from screen to storage.
Words on a screen lead you to The code behind it
Dos and don'ts
- Search the project for the exact words on the screen.
- Read the file ending and one root file before you dig into folders.
- Ask the AI to write a short map of the folders into AGENTS.md.
- Edit downloaded packages or build leftovers, whatever their folder is called.
- Assume every project uses src/ and node_modules/.
Followed exactly
There's no magic in source code, and you can open and read any file. The computer follows the text exactly, with no judgment. It does what the text says. Anything you meant but left out becomes behavior nobody chose.
Which folders are yours
A project looks huge because most of it belongs to other people. A few folders hold the code that matters — screens, shared helpers, tests — but the names vary. Some apps use app/ or src/; others put code at the root. Downloaded packages and build leftovers sit in folders you normally never edit (for example node_modules/, a Python .venv/, or bin/ after a C# build).
Spot language, file type and settings
The letters after the last dot name the kind of file. .js is JavaScript; .ts / .tsx are TypeScript; .py Python; .java Java; .cs C#; .css how a page looks; .html page structure. Some endings are settings or notes, not the program itself: .json, .yaml / .yml and .toml hold configuration; .env holds secrets (never commit real values); .md is Markdown — readable text used for README files and agent instructions such as AGENTS.md. Root files such as package.json, requirements.txt or a .csproj also name the stack. Ask the AI which language this project uses and what command starts it.
Follow one path
Every project has an entry point, the first file that runs. To find the code behind a screen, search for the exact words on it, such as Save contact. Ask the AI to write a short map into AGENTS.md, then check one route yourself.
Map my project without assuming src/ or node_modules/. From the root, list the file endings you see and what each one suggests. Name the folders that hold my code versus downloaded packages or build leftovers. If I have a Save contact screen, trace that path.
Example
Open my AGENTS.md and check the project map against the real folders. Do not invent src/ or node_modules/ if they are missing. Add any folder that is missing, remove any that no longer exists, and confirm the entry point. Show me the diff before saving.
Paste into your agent inside a project folder. Prompts that say "this project" are for the app you build in the Lab, or any app you already have. No project yet? Read them now and paste them later, in the Lab.
Map this project for me without assuming src/ or node_modules/. List the top-level folders with one line each, name the entry point, and mark which folders are generated and must never be edited by hand. Put the result in AGENTS.md under a Project map heading.
Show me the path the Save button on the contacts page takes: the file with the button, the request it sends, the file that receives it, and the function that stores the data. Name each file and nothing else.
Before you make this change, list every file you plan to touch and say which part of the project map each one belongs to. If any file is outside the map, stop and explain why.