Learn CAIN Proof-Carrying Code: from zero to expert, then sell it

No AI background needed. Five levels, each with something to actually do, at your own pace. Tick items as you go (your ticks stay in this browser).

Evidence, proof and selling tools for CAIN Proof-Carrying Code

Level 1 Beginner: understand it

CAIN Proof-Carrying Code checks code an AI agent wants to run before it runs: it must parse, import only allowed modules and contain no dynamic execution (eval, exec, os.system). Pass and it is certified; fail and it is refused.

Think of it like this: A building inspector who reads the plans and refuses any with a door to the gas main.

Read the full plain-English explanation: CAIN Proof-Carrying Code, explained.

• I read the explanation above.
• I can say what it does in one sentence, without notes.

Level 2 User: see it work

Run it live: open the live demo. Before each result, guess what will happen. These are checks it must pass:

• A pure function: add(a, b): Nothing dangerous.
• Import os; os.system('rm -rf /'): Shell access refused.
• A function that calls eval(): Dynamic execution refused.

• I ran the live demo.
• I can explain what one of these checks shows.

Level 3 Verifier: prove it yourself

This is the skill that sets you apart: you don't have to believe us, and neither do your customers.

1. Install Python 3 if you don't have it (python.org/downloads).
2. Download the kit and unzip it.
3. Open a terminal in that folder. On Windows, click the folder's address bar, type cmd and press Enter. On a Mac, right-click the folder and choose New Terminal at Folder.
4. Run python3 verify.py (on Windows, python verify.py). It checks the seal without the internet.
5. Run python3 verify.py --live. It repeats every check from your own computer.
6. Try to cheat it: open transcript.json in a text editor, change one character, save, and run python3 verify.py again. It must now say FAIL. Unzip a fresh copy afterward.

• I ran the kit's check on my own computer.
• I changed a file and saw it fail.

Level 4 Expert: know the edges

An expert knows what a product does not do, and says it first. That is what makes a buyer trust you.

• The checks shown are static analysis of the code's structure. The homepage card describes Z3 and Hoare-logic proofs; sell what the demo shows.
• Python only.
• It checks code, not what the code's data will do.

You can say

• Code with shell or dynamic execution is refused before it runs.

Never say

• "Unbreakable" or "stops every attack".

Read the questions real buyers send, with honest answers: answers to buyer questions.

Test yourself (click a question to see the answer)

• I got every quiz question right without looking.
• I can name one thing it does not do.
• I explained it to a friend, and they understood it.

Want a formal study path? The CAIN Academy has courses and exams. Finishing this page is your own practice; it is not a qualification or certification.

Level 5 Seller: put it in front of a customer

1. Copy, paste, send: the shortest route, no technical skill needed.
2. Who buys it and where to find them.
3. The sales conversation, then the offer and the close.
4. The rules: read these before your first message.
5. Selling tools with this product's evidence built in: pitch, emails, call script, objection answers, one-pager.

• I read the rules.
• I sent my first personal message.

About money: your share is agreed in writing with FIRME AI CORPORATION before your first message (email vincent@firmeai.com). Nothing here promises income. Most messages get no reply; that is normal.