CITE THIS CARDTHE PROVING CARD, Edition 2. Lund Studio LLC, Westminster, Colorado. https://lundr.tech/?view=proving-card. Punch 7AFD793DFD55A77E46DB4E73. Retrieved 2026-10-10.
What it is.
Reads a script and says whether it can prove itself: a selftest that builds its own fixture, prints PASS or FAIL per check, and exits 1 on any failure. Where there is none, it writes the skeleton beside the script, one stub per command.
The skeleton is a shape, not a proof; the assertions are the author's.
Its laws, written into the card.
A script with no selftest is unproven, whatever its README says.
The skeleton is a shape, not a proof; the assertions are the author's.
A selftest that does not exit 1 on failure is not a selftest.
How it works, once your AI has it.
NAME — `This is THE PROVING CARD.`
ASK — the script.
CHECK — for a selftest that builds its fixture and exits 1 on failure.
SCAFFOLD — where there is none, the skeleton, one stub per command.
RUN — the selftest until it passes and exits clean.
LEDGER — write the ledger line.
When it says no.
Writing the assertions — a stub that always passes is a lie.
Other languages: says so and stops.
Calling a script proven on the strength of a docstring → THE PORTABLE CARD checks the same script for what it needs installed.
What’s in the buy.
CARD.md — the whole card · SKILL.md — the door your AI reads first · START-HERE.md — the first five minutes
references/THE-METHOD.md · EVALS.json · EVALS.md · scripts/evals.py — the method, its template, and the tests with their runner
MY-LEDGER.md · TIN.md · LICENSE-NOTE.md · THE-CLAUSES.md · card.svg + card-machine.svg + card.json · card.html · the doors for ChatGPT, Gemini, Cursor, Copilot and the rest, and an MCP door
ON EVERY DOOR · A CARD FOR YOUR AI, A FILE FOR YOUR COMPUTER
In Claude: turn on code execution under Settings › Capabilities, then Customize › Skills › + › Create skill, and upload the zip as it is — START-HERE.md in the box walks you through it, and tells you how to keep the ledger. In ChatGPT, Gemini and the rest: a Project, a GPT or a Gem with the card’s files attached and the short door in the box pasted as its instructions. The words run anywhere an AI reads Markdown; the machines run wherever the host runs Python. Witnessed in Claude only. The host marks →
Take it.
Nº 673 PROPOSED · ONE PAYMENT
Sold as is under the term printed. A card instructs an AI you operate; results depend on your model, your files and your judgement. Not legal, tax, medical or financial advice. The terms →
One payment. The file is yours to keep and keeps working at its edition; new editions issued in the year after you buy reach you by email as replacement files. Tax is added at checkout where it applies. Nothing auto-renews.
ONE PAYMENT — NOTHING RENEWS ITSELF. CHECKOUT IS SHOPIFY’S OWN; YOUR CARD COMES BY EMAIL AFTER IT.
