The accounting module is the hardest test the design system will ever face: an append-only journal, running balances, two-sided entries, three-way matching, reconciliations that must tie to the cent, dual control, period locks, gapless statutory numbering, multi-currency on every line, and an AI agent posting within a delegation. Lab 18 walked it as part of the whole platform; this lab walks it alone, route by route and data-nature by data-nature, against the platform's own module document, to answer one question: is anything still missing?
The honest answer: no new components are needed. The eight primitives the audit added for this module carry every surface. The walk found two places where a rule needed one more sentence to survive an accountant's scrutiny, both now written in, and two adoption notes that cost nothing today.
Drawn fresh from the Untitled kit and the system’s ruled tokens, not restyled from the originals.
| Date | Journal | Debit | Credit | Balance |
|---|---|---|---|---|
| 14 Sep | Client receipt · WIRE-88377 | 25,000.00 | 118,400.00 | |
| 15 Sep | Supplier settlement · marketplace | 21,340.00 | 97,060.00 | |
| 16 Sep | FX revaluation · rate stamped | -412.00 | 96,648.00 | |
| 17 Sep | Unmeasured period | - | - |
Signed mono, never parentheses; zero, dash and blank are three facts; the running balance exists only in date order.
The walk validates design coverage, not the accounting itself: the tax profiles, allowance rates and thresholds still carry their consultant-confirmation flags in the module document, and adoption of the system by the shipped module remains ruled "Not yet". When adoption comes, this lab is the checklist of what changes: the deltas go achromatic, the ledgers gain L17's behaviour, and everything else is restyling, not rethinking.