Three spec decisions from Stephen (2026-10-13), raised by the spec-blind
test writers, each test-first:
- A payment dated before its invoice or bill is refused
(PaymentBeforeDocument); a real prepayment is a deposit. Test:
a_payment_never_predates_its_document. Replay is unaffected (it goes
through replay_invoice_payment / replay_bill_payment).
- Aging as of a date shows only documents issued by then, less only the
payments made by then. The ledger now records each document's payment
entries (live and on replay), and aging counts those dated by as_of.
Test: aging_as_of_a_date_sees_only_what_existed_then; the A/R and A/P
conservation properties' aging oracles updated to the confirmed rule
(they had assumed aging ignored dates).
- A schedule through a mid-month date prorates that month by days; the
code was right and its doc wrong. The spec-blind test that disagreed is
rewritten to the confirmed spec and no longer ignored.
Also found while wiring payments: a payment to an unknown cash account
created the payment's draft and then failed, leaving it behind; the cash
account is now checked before anything is created.
The unreviewed golden van_schedule.json is gone: every row was first
checked against an independent hand computation (all 61 matched), then
replaced by van_schedule_is_the_hand_computed_one, which asserts that
computation directly (548.39, 59 x 1,000.00, 451.61; total 60,000.00).
Tests: 452. No spec-disagreements left ignored.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Max-testing pass, steps 2-4.
Spec-blind tests (rank 1-2): four agents, each given only the specs and
the public interface (doc comments and signatures, every body removed,
never src/ or the existing tests), wrote tests/spec_reports.rs (62),
spec_ledger.rs (72), spec_arap.rs (42), spec_assets_payroll.rs (50):
hand-computed examples per scenario and a proptest law per invariant
(conservation, partition, invariance, scaling, reversal cancels,
"a refusal leaves the books unchanged" over random invalid commands).
They found:
1. A refused payroll run changed the books: an all-zero run passed
validation, then failed at post after creating seven payroll
accounts and using up an entry id. validate_payroll_lines now
refuses a run with no gross pay.
2. A refused add_account used up an account id (empty code, duplicate,
unknown parent). The id is now taken only when the account is added.
3. Stale prose: close_period_to and members_equity still described the
old last-member rounding.
4. Open (left #[ignore]d pending Stephen): depreciation_schedule's doc
says "through the month containing" the date; the code prorates that
month by days.
GnuCash oracle (rank 3, an oracle never the spec): `just oracle` builds
GnuCash 5.10 in a container pinned by base digest and package versions
(oracle/gnucash/) and runs tests/oracle_gnucash.rs: 200 seeded random
books built through wanderbooks (entries, foreign lines, reversals,
monthly closes), every account's balance at month ends and random dates
and each month's P&L, compared exactly: 15,800 comparisons. First run:
4,724 differences, all from foreign lines; without them, zero.
Adjudicated from principles (rules.md B-3): wanderbooks booked
foreign * rate unrounded ($108.34567); a ledger in one money holds no
fractions of its smallest unit, and its cash must match a bank. Stephen
decided: book in the base currency's minor unit, half away from zero.
add_line_fx now rounds; minor units per ISO 4217 list one (2026-09-17,
SIX), generated into Currency::minor_units and recorded in
docs/spec/sources/iso-4217.md. Replay now takes the journaled base
amount (replay_add_line_fx), so lines booked before replay exactly as
booked (contract: books_written_under_older_rules_still_open). Now:
zero differences, foreign lines included.
Tests: 449, from 223.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Three spec decisions from Stephen (2026-10-13), each test-first:
- A child account has its parent's type (ParentTypeMismatch): a child
subdivides its parent. Test: a_child_account_has_its_parents_type.
- Periods nest (a month in a quarter in a year) but never partially
overlap (PeriodsOverlap; a refusal uses no id). Test:
periods_nest_but_never_partially_overlap.
- A line's account must exist and take postings when the line is added,
not only at post (UnknownAccount / PlaceholderAccount from add_line
and add_line_fx); posting still re-checks. Two older tests that pinned
the post-time refusal now check both (the post-time check is reached
through the unchecked replay path, as old journals can).
Compatibility: replay reads history through new Ledger::replay_*
commands (add_account, add_line, add_line_fx, create_period) that skip
checks added later, so books written before these rules still open.
The contract test books_written_under_older_rules_still_open writes such
a journal directly and found, on its first run, that the SQLite
cross-check rebuild used the checked commands and would have failed
verification ("sqlite projection can't be read back"); it now replays
too. Documented in docs/spec/README.md; decisions recorded in rules.md
(B-1, B-4, B-12).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Stephen (2026-10-13): when what wanderbooks knows is stale, check the
date, research it or ask the owner or CPA, and update the rule for
everyone with a pull request (best) or an issue (worst).
- ledger_core::rules: a registry of rules set by law that change over
time. Each says the years it's known for, its rules.md entry, its
vendored official source, and a review date. stale_rules(today) is
pure; the engine has no clock.
- The 1099 threshold is the first: $600 through 2025, $2,000 in 2026,
then indexed for inflation (26 U.S.C. §6041(h)). default_threshold
and vendor_1099_report now return Result; for 2027+ they refuse with
LedgerError::RuleNotKnown, whose message says what to do: get the
figure from the official source or the owner/CPA, pass it explicitly,
then open a PR (or issue) at github.com/swaits/wanderbooks. Before,
2027+ silently used $2,000.
- MCP: books.vendor_1099 relays that refusal; books.digest gains
stale_rules; the server instructions tell the agent the procedure (and
how to handle control-account conflicts: explain, never renumber).
The CPA package writes a NOT-INCLUDED note instead of a guessed 1099
worksheet.
- Viewer: "Needs attention" shows each stale rule with a ready prompt
for the agent; the 1099 page explains instead of guessing.
Review date for the 1099 rule: 2026-11-01, when the IRS usually
publishes next year's inflation adjustments (CONVENTION, marked as such
in the registry).
Tests: an_unknown_year_threshold_is_never_guessed,
dated_rules_go_stale_on_their_review_date (dates passed in, so no clock
in the test), MCP stdio: 2027 refused with guidance, explicit threshold
accepted, digest carries stale_rules (asserted date-independently).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Stephen asked that specs come from recognized documents, not from
anyone's memory. There is no single US bookkeeping bible; authority is
layered, and this records it:
- docs/spec/sources/: verbatim excerpts (whitespace normalized), each
with URL, retrieval date, and the SHA-256 of the fetched file, of
public-domain texts: Pacioli's 1494 treatise in Geijsbeek's 1914
translation (double entry, the trial balance, one money, write only
forward, correct by opposite entry, close into capital); IRS Pub. 583,
538, 946, 15; the 1099-MISC/NEC instructions (2025 and 2026); 26 U.S.C.
§6041, §6041A, §704; Treas. Reg. §1.263(a)-1(f) and -4(f); Notice
2015-82; Rev. Proc. 98-25; Form 1065 instructions; 17 U.S.C. §105. The
excerpts were extracted by matching each passage against the fetched
file, so none can contain text the source doesn't.
- docs/spec/rules.md: the rule catalog, B-1 to B-22. Each rule says
AUTHORITY, CONVENTION, or DECISION; cites its sources (FASB's
Codification and Concepts Statement 8 and OpenStax quoted briefly,
never copied: copyright and CC BY-NC-SA); and names the code that
enforces it and the tests and proofs that check it.
- Spec blocks in the code now carry SOURCE: lines into the catalog;
AGENTS.md makes sourcing rule 0 of the formal-methods bar.
Corrections the sources turned up: the de minimis limit is $500 in the
regulation and $2,500 by Notice 2015-82 (both now cited); 1099
thresholds after 2026 are inflation-indexed, so the engine's flat
$2,000 for 2027+ is an open question (B-19). Unverified ASC paragraphs
(360-10-35-4, 340-10, 230-10-45-10, 606-10-55-37B, 210) are listed in
docs/spec/README.md until someone with a FASB basic-view login reads
them.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
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