# Basel III calculator validation

Updated October 8, 2026. Regulatory input schema and calculation engines: version 1.0.0, with rules dated October 8, 2026.

## Implemented

- Transaction: funded and contingent exposure, contractual CCF selection, credit RWA, capital targets, narrow eligible protection, annual economics and return on attributed equity.
- Portfolio: selected/excluded membership, partial totals, unresolved balances, facility and borrower contributions, reviewed CSV imports and explicit duplicate replacement.
- Bank Impact: add, replace and remove; explicit baseline membership; separate capital changes; matching leverage denominators; complete BCBS reference output-floor aggregates.
- Comparison: two independent scenarios, changed inputs, both rulesets, declared coverage and right-minus-left deltas.
- Records: current-input checks, independently recalculated JSON imports, read-only unknown versions, preserved original files, full-precision JSON and CSV downloads.

New workspaces have blank financial balances and unconfirmed eligibility. Synthetic balances appear after Load example. Inputs stay in memory in this page; download them before closing or reloading. Browser device storage and server persistence are not used.

## Automated verification

291 Node test cases pass: 253 retained Basel engine/input tests, 16 session/transfer tests, 18 DOM-adapter interface tests, and four existing NAIC test suites. Module syntax and local asset references pass. The interface adapter exercises the actual bound handlers and rendered markup; it is not a visual browser.

Verified cases include:

| Case | Result |
|---|---:|
| $100m revolver hold, $40m funded, five-year original maturity | $70m exposure and RWA |
| Change original maturity to one year | $52m exposure and RWA |
| Comparison at a 10% CET1 target | RWA change -$18m; required capital change -$1.8m |
| $10m term loan plus the original revolver | $80m RWA and $8m CET1 at 10% |
| Third unresolved $5m funded position | $80m partial RWA; 2 of 3 selected facilities calculated |
| $10bn CET1, $100bn baseline RWA, add $1bn RWA | 9.900990099% CET1 after; $910m headroom at 9% |
| Annual economics example | $180,000 after-tax profit; 18% ROAE |

Tests also cover loss-basis changes, no-relief scenarios, conditional fields, bank position revisions, source edits after transfer, duplicate IDs, imported-result manipulation, preserved unknown-version bytes, unsafe text escaping and invalid-number blocking.

[Machine-readable validation results](validation-results.json)

## Remaining browser checks

The Site uses static HTML and ES modules. A supported live browser preview was unavailable during this release. Desktop/mobile visual review, keyboard and screen-reader behavior, 200% zoom, native file dialogs and actual browser downloads remain unverified. Responsive layouts, labeled controls, keyboard mode navigation, bounded scrolling tables, focus links and download handlers are implemented.

## Calculation scope

The U.S. option is the locked Federal Reserve Part 217 standardized snapshot. The BCBS option is a hypothetical reference. Ordinary corporate exposure eligibility must be confirmed. Fund equity, securitizations, specialized methods, broader protection mismatches and other jurisdictional implementations require separate calculation branches.

Capital targets are selected or entered explicitly and are not summed across nested categories. Bank results cover the selected denominator basis. Annual earnings do not automatically update regulatory capital. Attributed equity is an input under a documented allocation policy. Unavailable results remain unavailable; partial results identify their included and unresolved facilities.

Calculation and evidence status describe the supplied inputs and implemented checks. They do not independently authenticate the underlying source documents or determine a bank's full regulatory position.