- core: TaxBasisRule (cost IRC 1012, carryover IRC 723, personal-use conversion Treas. Reg. 1.168(i)-4(b)), TaxBasis with the contributor's adjusted basis, Asset::tax_basis and ::built_in_gain (IRC 704(c)); the register gains tax rule, contributor basis, tax basis, built-in gain, total tax basis, missing count (rules.md B-25; sources vendored in docs/spec/sources/irs-partnership-basis.md)
- store: asset.tax_basis_set journaled, replayed, projected (schema v10)
- mcp: books.set_asset_tax_basis; register_asset takes tax_basis_rule and contributor_basis, checked before anything registers (found by the spec-blind suite); list_assets and the register export (json, csv) carry tax basis; instructions say to record it for every asset
- import: the register's XLSX and PDF gain the federal tax basis table with citations
- viewer: tax basis on the Assets page, the asset page (a Tax basis card), the report, the journal, and Needs attention for assets without one
- just: check and the mutation recipes sweep this user's test book dirs older than an hour (killed runs had left 23 GB in RAM-backed /tmp)
- docs: the parties, attachments, TIN vault, completeness engine, and updates designs (docs/parties-and-attachments.md)
- tests: spec-blind tax basis suites in core, store, MCP; register PDF/XLSX and viewer tests
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
- core: asset tags (generated PREFIX-0001 or the human's own; unique ignoring case; never reused by another asset) and serial numbers (rules.md B-24); a journaled link from an asset to the entry that acquired it (posted, unreversed, debiting the cost account); fixed_asset_register(as_of), reconciled to the GL (unposted depreciation, unregistered cost)
- store: asset.tagged, asset.serial_set, asset.acquisition_linked journaled, replayed, projected (schema v9); differs_from now also compares control roles and tag history
- config: [books] asset_tag_prefix, default the company's initials without legal-form words
- import: Avery 5160/8160 label sheets with QR codes (geometry vendored from Avery, docs/spec/sources/avery-5160.md); the register as XLSX and PDF
- mcp: register_asset tags (and links) automatically; books.label_asset, books.asset_labels; asset tools take a tag; books.show asset / assets page / register report; export fixed_asset_register (json, csv, xlsx, pdf) and in the CPA package
- viewer: Assets page (register, reconciliation), asset page (identity, schedule posted vs not, entries, documents), Fixed asset register report, global search by tag/serial/description, journal text, needs-attention items
- fix: verify compared snapshot amounts as strings; a zero total summed in hash-map order could print "0" or "0.00", so agreeing books failed verify at random. Now by value (regression test)
- tests: spec-blind suites for tags, register, prefix, store, MCP; label and register PDF/XLSX tests; viewer tests
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
- core: ControlAccount keys, Ledger::assign_role/check_assign_role/role_account (rules.md B-23): one account per role, of the role's type, balance sheet roles move only when empty; invoices, bills, payroll, remittance, and closes post to the assigned account; an assigned role frees its default code for renumbering
- store: role.assigned journaled and replayed (strict account_id)
- mcp: settings.rs reloads by content at the start of each request, keeps the last good settings on a broken edit; books.settings with chart problems; digest settings_problems; instructions say when to edit the toml
- viewer: journal text for role.assigned
- cli: full example wanderbooks.toml, tested to load with every example uncommented
- tests: spec_roles.rs (25, spec-blind), store roles.rs (6), MCP reload/problems/roles, settings unit tests
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Ledger::renumber_account changes only the code (entries name accounts by
id): refuses an unknown account, a blank or used code, and a control code
for an account of the wrong type or a placeholder. Journaled as
account.renumbered (with the previous code), replayed, projected, shown
in the viewer's journal. The MCP tool lists wanderbooks.toml settings
that still name the old code. The server instructions now warn that the
engine can't tell a same-type account with another purpose at a control
code (a hosting expense at payroll's 6100).
Tests: core property (only the code changes; trial balance equal), core
refusals, the store's command property, MCP end to end with restart.
Mutation on the new code: 8 of 8 viable caught.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
New vendored sources (docs/spec/sources/): Intuit's bank CSV upload and
IIF formats, ECMA-376 / Excel number storage, and the IRS form lines the
tax categories map to.
IIF export (rewritten to Intuit's IIF Import Kit):
- declares every account first (!ACCNT NAME, ACCNTTYPE, ACCNUM): an
undeclared account is created in QuickBooks "as a new bank account";
the MCP export types them (cash accounts BANK, the control accounts AR
and AP, registered fixed assets FIXASSET, the rest by type);
- subaccounts by colon path, parents first; colons in a name replaced;
- ASCII only (IIF is ASCII text), dashes and quotes transliterated;
- the kit's 2007+ journal layout and M/D/YYYY dates; an entry using an
undeclared account is refused.
Bank CSV:
- the 4-column layout is money out then money in by position, which
matches Intuit's "Credit, Debit" and banks' "Debit, Credit" both (the
doc's "Expense, Income" labels were wrong, the parsing was not);
- a slash date's order comes from the file (a part over 12 settles it)
or the caller's new date_order, never a guess: Intuit recommends
dd/mm/yyyy, US banks write mm/dd/yyyy;
- fractions of a cent and double negatives ("(-5)") are refused; the
header is recognized on the first non-blank row.
Chart CSV: a blank code or name is refused with its row (found by the
new fuzz_import_csv target), and the core now refuses a blank account
code or name too (replay keeps older books).
MCP:
- books.import_chart_csv and books.import_bank_csv rehearse the whole
file on a copy of the ledger first: a bad row anywhere refuses the
file (before, a duplicate within the file, a parent after its child,
or a date in a closed period left earlier rows behind);
- bank rules: the longest matching pattern wins (they arrive in a map,
so "first match" changed from run to run).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
The refusal property gained the converse law (an accepted command
journals something; only batch runs may find nothing to do) and checks
the store's class and payroll listings. It found a schedule registered
with an out-of-range total whose first month was refused after its entry
was begun: the live ledger kept a draft the journal never had.
- Core: compound commands (post_schedule_month, reverse_entry,
close_period_to, create_invoice, create_bill, receive_payment,
pay_bill, run_payroll, remit_payroll_taxes) run inside
Ledger::atomically, so a refusal partway leaves the ledger exactly as
it was.
- Core: a schedule total no line could carry, or finer than a cent, and
an asset cost beyond the line range, are refused at registration.
Replay keeps older schedules (replay_register_schedule).
- Store: add_line, add_line_fx, mark_cleared, set_fx_rate,
post_schedule_month and close_period_to changed the live ledger before
journaling; they now run on a copy, journal what it produced, then
swap it in, so a failed write leaves the live books as journaled.
New spec-blind suite tests/spec_store.rs (57 tests written from the
store's specs alone). Its two findings, adjudicated:
- A file filed twice under different names listed the first name and
type for both (the projection kept them per blob). Schema v8 gives
each attachment its own; older databases backfill and heal by verify.
- Withdrawn attachments stay in the store's listing, marked (the MCP
listing hides them): the spec and doc said "omit" and are corrected.
Also removes journal::truncate_to_last_good_seq: unused, and it dropped
everything after the first bad complete line, which the books now treat
as corruption for a person, never repaired automatically.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Each close into members' capital rounded on its own, ties to the
earlier member, so twelve monthly 50/50 closes of odd-cent income could
leave one member several cents ahead of half the year (docs/testing.md
#12, found with the members' equity fix).
- CloseTo::Members now splits cumulatively over a run (closes back to
back with the same members and shares): each close gives a member
allocate(run total so far) - allocate(run total before). Periods
record their close order and a cumulative close's members and net
(Period::close_seq, member_close) so the next close continues the run
and replay recomputes it exactly. A close to anything else, or other
shares, ends the run.
- Journaled "rounding": "cumulative". The per-close rule is kept as
CloseTo::MembersPerClose for closes journaled "largest_remainder";
older closes still replay with the last member absorbing it.
- Lean: runPart_telescopes (a member's total from a run is their
allocation of the run's total) and closePart_total (each close hands
out exactly its net), audited to the standard axioms.
- Tests: hand-computed three one-cent months (per close A 0.03 / B 0;
cumulative A 0.02 / B 0.01), a run ending, a property that each member
stays within a cent of their share (fails on the per-close rule), and
a store contract that each rule journals and replays as itself.
Wanderland's books have no closes yet, so all of theirs use the new rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
CI's run of the store refusal property found a payroll run that posted
$65.27794: the employer tax was passed in unrounded and nothing refused
it, though rules.md B-3 already says a ledger in one money holds no
fractions of its smallest unit. Sums of it then differed in scale
between journal replay and the SQLite read-back.
- Ledger::post_entry refuses any line finer than its currency's ISO 4217
minor unit (FinerThanMinorUnit), whatever made the line: payroll,
closes, disposals. add_line refuses it up front. Older journals replay
as booked through replay_post_entry. Spec tests for the kernel's
ten-place limit now run on the replay path.
- The property's body is now run_ops, so failing sequences become named
regression tests (regression_payroll_with_a_fraction_of_a_cent). The
generator rounds payroll tax to the cent, as callers must.
- Ledger derives PartialEq and gains differs_from; Store::verify compares
the live ledger with the journal replay in full (drafts, documents,
schedules, periods, settings), not just balances, and names the parts
that differ. The property checks the ledger its commands built against
that replay and against the reopened books.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
The refusal property now starts from real books and adds compound
commands with valid arguments (book an entry, register an asset or
schedule, raise an invoice or bill, close a month to members), so every
command's success path is exercised. Compound commands checkpoint after
each step, so the law is checked against the one command refused.
STORE_CASES sets the case count (256 by default).
It found two bugs:
- run_recurring created drafts dated inside a closed period (B-12).
generate_recurring now refuses them, atomically; the store leaves
them ungenerated and books.run_recurring reports them in
skipped_closed_period for a human to decide. Replay uses
replay_generate_recurring so older journals still open. The store
also journals before mutating the ledger here, as everywhere else.
- Disposing an asset for no proceeds (scrapping it) journaled a
catch-up depreciation entry and a half-built draft with a 0.00 line,
then refused. Zero lines are now left out (Store::disposal_lines,
shared with the MCP preview), and the whole disposal is rehearsed on
a clone before anything is written.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Max-testing pass, step 8. The final mutation run left 112 survivors
(89% caught). Three agents triaged them by file, by the playbook's
table: spec the boundary then test it, a law rather than one more
pinned value, assert the real value, never weaken a test. Every expected
value is hand-computed.
- reports.rs (35): 28 killed, chiefly cash flow (inclusive start date,
each line's sign and label, a loss on disposal moving to investing,
financing designation), general ledger and members' equity date
boundaries, and the balanced() checks (a real report nudged by a cent
must stop balancing). 7 equivalent: four >/>= after an early return on
zero; two in dead code (removed in this commit); one sign of a zero
cleaned on output.
- ledger.rs, kernel.rs, journal.rs, money.rs (52, plus one new): 49
killed, including every replay_* mutant at the core level (ids,
accumulation, status, vendor tags, out-of-order refusal), FX rates,
0%/100% deductible boundaries, a dividend sweep with no income, the
legacy member rounding at close, a bill paid on its own date, a
liability-account reconciliation, mixed-currency entries (via serde),
ISO 4217 minor units, Display/Debug. 3 equivalent: zero refused before
a </<= check; a period whose end is in a closed period refused earlier;
columns(0).
- schedules, tax, analysis, payouts, assets, form1099 (25): 23 killed
(schedule length 1-600, recurring end on its start, frequency parsing
and stepping, cost of goods in tax net, a zero payout, disposal on the
purchase date, quarter starts, labels); 2 equivalent (zero adds zero;
days_held is provably >= 1).
Two small production cleanups the triage surfaced: kernel::columns(0)
returned a negative-zero credit that would print "-0" (regression
a_zero_movement_has_no_negative_zero_column, shown to fail before); and
cash_flow computed a book value it never used.
Spec lines added where a boundary wasn't specified (cash flow's
inclusive start and line signs, members' equity start date, payout with
no deposit, disposal on the purchase date, bill paid on its own date).
`just mutants` now runs core and store tests (the store's replay tests),
not the whole workspace, which rebuilt the viewer for every mutant.
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), 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
Max-testing pass, step 2: every domain decision in ledger.rs and
reports.rs gets a GOAL / SOURCE / INVARIANTS / SCENARIOS block in its
doc comment: post_entry, try_create_entry, close_period_to,
mark_cleared, reconciliation_report, account_balance, create_invoice,
create_bill, receive_payment, pay_bill, register_asset, dispose_asset,
run_payroll, remit_payroll_taxes, set_line_class, set_entry_vendor;
trial_balance(_as_of), profit_and_loss_for_period, balance_sheet_as_of,
general_ledger, members_equity, cash_flow, profit_and_loss_by_class,
snapshot. Sources trace to docs/spec/rules.md (and through it to
Pacioli, the IRS, FASB); what no document settles is marked CONVENTION,
DECISION, or ASSUMED for Stephen to confirm. The specs are the input to
spec-blind test writing (the next step): tests derived from the spec
alone, never from the code.
Also: rustdoc now runs in `just check` with -D warnings; fixed the seven
existing broken intra-doc links and one bare URL.
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
Invoices, bills, payments, payroll, and closes post to accounts the
engine finds by code (1200, 2000, 4000, 6999, 3999, 6100-2150). If an
account with that code existed it was used whatever its type: a 1200
"Customer Deposits" liability would have taken receivables. Now
(Stephen, 2026-10-13: never force an imported chart into our numbering)
the engine refuses with ControlAccountMismatch, naming the code, the
account, its type, the role, and the type needed, so the agent can work
it out with the human. A placeholder is refused too.
Every command checks all its control accounts before changing anything
(Ledger::check_controls, spec + SOURCE in its doc comment), so a refusal
never leaves a half-made account behind. One table of control accounts
(ledger_core::RECEIVABLES ... PAYROLL) replaces the codes duplicated
across the engine and the store.
Tests (spec-derived, all assert the books are untouched after the
refusal): an_invoice_refuses_a_1200_that_is_not_receivables,
an_invoice_refuses_a_placeholder_1200,
an_invoice_creates_nothing_when_its_second_account_is_wrong,
a_bill_refuses_a_2000_that_is_not_payables,
a_close_refuses_a_3999_that_is_not_equity.
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
Max-testing pass, step 2: two spec decisions Stephen confirmed
(2026-10-13), each test-first.
Aging (arap::aging_bucket): a document due today was "1-30 days past
due"; it is Current, since past due starts the day after (QuickBooks'
convention). Spec in the doc comment. Boundary examples at every edge
(due today, 1, 30, 31, 60, 61, 90, 91 days) fail on the old code. A
property: the balance lands in exactly one bucket, and time only ages
it.
Member splits (periods::allocate): the last member absorbed every odd
cent, so the same partner always got or lost it. Now largest remainder:
each share rounded toward zero to the cent, leftover cents to the
largest remainders, ties to the earlier member, a loss the negation of
the gain. The core is a new kernel function, kernel::apportion,
allocation-free so Kani proves it (n <= 3): apportion_is_exact (it
succeeds exactly when the shortfall is under a unit per part; then the
parts sum to the whole, each gains 0 or 1 unit, one may take the
sub-unit fraction) and apportion_is_fair (never a unit to a part while
a larger remainder goes without). Kani found an off-by-one in the first
version: a shortfall of n units plus a fraction was accepted. Native
regression apportion_refuses_a_shortfall_of_a_unit_per_part_or_more.
Properties at Decimal (2,000 cases, up to 5 members): conservation,
within a cent of each exact share, fairness, sign symmetry; they fail on
the old rule. Bridge: apportion agrees on i64 and Decimal.
Contract: closes journaled before this change replay exactly. New
member closes journal "rounding": "largest_remainder"; journal lines
without it replay as CloseTo::MembersLastAbsorbs, the old rule
(periods::allocate_last_absorbs, pinned by
closes_journaled_under_the_old_rule_replay_with_it). The members'
equity statement isn't journaled and uses the new rule.
Open gap: Lean proof of apportion's sum law for any n (needs a
permutation lemma on the ranking); Kani covers n <= 3, properties n <= 5.
The Lean closing theorems already hold for any split summing to the
net.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Max-testing pass, step 2 (rank 1 regressions + a rank 2 law). Two ways
to make the books unopenable, both found by test, both fixed:
1. Reversing into a closed period: the store journaled `entry.reversed`,
then the engine refused it at post. Replay could never apply that
line, so Store::open failed ("period 1 is closed"). Regression:
reversal_into_a_closed_period_is_refused_before_journaling.
2. An oversized invoice (or any command whose hand-written store
pre-checks lagged the engine, here the new line range) journaled,
then failed in the engine. Found by the new property
refused_commands_never_reach_the_journal within 4s.
The fix is structural, not another hand-written check: every
journal-first store command now rehearses on a scratch clone of the
ledger (`Store::rehearse`), so whatever the engine refuses is refused
before the journal, now and after any future engine change. The
create_entry rehearsal uses the checked constructor: no draft is ever
dated in a closed period (the Lean invariant Inv.draftsOpen, which the
store had bypassed).
The property (1,000 random command sequences, heavy on refusals)
asserts, after every command: a refusal leaves the journal
byte-identical; every posted entry validates; the trial balance
balances; no draft sits in a closed period; and the books reopen and
verify at the end. Shown to have teeth: removing the create_entry
rehearsal makes it fail and shrink to open-period, close, draft.
Engine (spec confirmed by Stephen, 2026-10-13), Ledger::check_reversal,
a pure pre-check that reverse_entry and the store share:
- an entry is reversed at most once (EntryAlreadyReversed); reversing
the reversal re-instates it;
- a closing entry is never reversed (ClosingEntryIrreversible);
- a refused reversal leaves no trace (it used to leave a draft and
burn an id).
Specs go in doc comments as a ```text GOAL/INVARIANTS/SCENARIOS block.
New dev dependency: proptest for ledger-store (already the workspace's
property library).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
The money arithmetic every invariant rests on now lives in one kernel,
ledger-core/src/kernel.rs: signing a line, totals, net, per-account
movements, reversal, normal balances, trial-balance columns, closing
lines, and the rounding plug for member splits. It is generic over a
checked `Amount` trait. The engine runs it on Decimal (validate,
movements, reverse_entry, account_balance, close_period_to, allocate,
trial_balance): there is one copy of the arithmetic, and it is the one
under proof.
Three layers, docs/verification.md maps every law to its proofs:
- Kani (src/proofs.rs): 17 harnesses prove the kernel at i64 for every
input up to 4 lines over 3 accounts. An entry is accepted exactly
when it is two or more positive, in-range lines whose debits equal
credits; accepted entries net to zero; grouping by account loses
nothing; a reversal mirrors and cancels its original; trial-balance
columns balance iff the books net to zero; closing lines zero their
accounts and a close balances however the net is split; the plug
makes parts sum to the whole. No panics, no overflow. kani::cover!
shows the proofs are not vacuous.
- Lean 4 (verify/lean): 24 headline theorems for books of any size. The
ledger is a state machine (add account, draft, post, reverse, open,
close), and in every reachable state the books net to zero, the trial
balance balances (as of any date), and the accounting equation holds.
Posting only appends ("posted is forever"), closed periods are
frozen, a close zeroes revenue and expenses and credits exactly the net
income, and period statements add up. Audit.lean shows standard axioms
only, no sorry.
- Bridge (tests/kernel_bridge.rs): the Decimal and i64 kernels agree.
What the proofs found (each one missed by every test, fuzzer, and
mutant):
- The engine accepted negative line amounts; only MCP refused them. Now
NegativeAmountLine: direction is the side's job.
- Summing lines near Decimal::MAX panicked. Lines are now capped at one
quadrillion and ten decimal places (AmountOutOfRange), which keeps
every realistic sum exact, and the kernel's sums are checked.
- FX conversion (foreign_amount * fx_rate) could panic the same way; it
is now a checked multiply.
- Kani itself: 0.68 mis-models symbolic-length copy_from_slice
(model-checking/kani#4904) and reported a reversal that doesn't net to
zero. The counterexample, replayed natively, passes, and a 15-line
standalone crate reproduces the bug. Harnesses avoid bulk copies, and
a should_panic canary will flag the upstream fix.
`just prove` runs it all (Kani memory- and time-capped, fails on an
unsatisfiable cover or a non-standard Lean axiom). AGENTS.md now makes
formal coverage part of every core change.
Also, docs: GnuCash is *an* oracle, never *the* oracle (Stephen). The
spec is accounting principles, proved. Golden files are recomputed from
principles. External implementations (GnuCash, the old Sheet, QBO/Xero)
are cross-checks whose disagreements get adjudicated, never obeyed.
docs/oracle.md gains "Who is right"; AGENTS, README, architecture,
roadmap, parity, and STATUS are reworded to match.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX
Vendors carry form_1099 (NEC/MISC) and tin_on_file (never the TIN).
Entries carry the vendor they paid; bills, bill payments, and reversals
are tagged automatically. books.vendor_1099 counts cash paid per vendor
per calendar year (card payments excluded) against $600 through 2025 and
$2,000 from 2026, or an override, and flags missing W-9s. Four new tools
(64), two journal events, schema v7. Docs: finished R-FUTURE work is no
longer listed as future.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Amortization schedules spread a prepaid expense or deferred revenue over
the months it covers, to the cent, posting on month ends; runs preview
first, are idempotent, honor closed periods, and are exempt from the
receipt policy like depreciation. Recurring entries generate drafts only,
never posts. Six new tools (59 total); four new journal events, replayed
and checked.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Every business has owners, and how owners put money in and take it out
depends on what the business is. wanderbooks now knows the four common
US shapes:
- books.chart_template {entity_type, owners}: a starter chart for a sole
proprietorship (owner's capital and draws), partnership or
multi-member LLC (capital and distributions per partner, guaranteed
payments), S corporation (stock, APIC, shareholder distributions,
officer compensation, retained earnings) or C corporation (dividends,
income tax expense), plus common income and expense accounts with
tax categories, and the wanderbooks.toml settings that go with it
(tax form, members with equal-share placeholders that sum to exactly
100, close target). A proposal for the agent to review with the human.
- Closing: CloseTo is now RetainedEarnings { sweep }, Account { into,
sweep } (a sole proprietor's capital) or Members([MemberClose { capital,
share, distributions }]). Sweeps zero owner-pay equity accounts into
their target at close: draws into owner's capital, dividends or
distributions into retained earnings, each partner's distributions
into their own capital. Validation (equity, distinct, shares sum to 1)
runs in the pre-close preview, before anything is journaled. The
journal records the target; journals with no target or the old
"retained_earnings" string still replay.
- Members' equity: a partner's distributions account is part of their
capital; its activity reports as distributions.
- Config: members' distribution_account; [books] close_into and
close_sweep for single-owner businesses (rejected alongside members).
The cash flow names members on their distribution accounts too.
Tests: a sole proprietor (net 2,000 and 500 of draws into capital: 6,500,
the cash); a corporation (dividends 300 into retained earnings: 600); a
partnership with distribution accounts (Bob 100 + 25 - 20 = 105, swept at
close, February begins there); bad sweep accounts; templates round-trip
through the chart parser, unique codes, equity per entity, every tax
category valid for the entity's return; stdio: template -> settings ->
import -> postings -> close with the exact closing lines.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
wanderbooks is a general MCP-first accounting application: every
business needs its accounts mapped to where they land on its income tax
return, and its CPA needs book-to-tax differences surfaced, not hidden.
- ledger_core::tax: a catalog of stable categories (gross_receipts,
commissions_fees, meals, guaranteed_payments, officer_compensation,
nondeductible, ...) with kind (income, cost of goods, deduction), the
returns each appears on (Schedule C, 1065, 1120-S, 1120), a default
deductible percent (meals 50, nondeductible 0), and guidance. Keys,
not line numbers: form lines move from year to year.
- Accounts carry tax_category and an optional deductible_percent
override, validated against the account type (and the return, at the
MCP layer), journaled as account.tax_set, replayed, projected (schema
v6).
- tax_summary(start, end, form): the P&L grouped by category, book and
deductible amounts (half away from zero to the cent), contra income
(refunds) reducing receipts, and every account still uncategorized.
- MCP: books.tax_categories (filtered to the configured return),
books.set_tax_category, a tax_summary report in every format and in
the CPA package, chart output with categories, and a fifth
tax_category column in chart CSV imports, validated before anything is
created. [company] tax_form, or derived from tax_classification.
Scope stays book basis: no tax depreciation, basis, or filing.
Tests: a hand-computed quarter (50% meals 333.33 -> 166.67, penalties at
0%, refunds as negative receipts, guaranteed payments, one uncategorized
account; book net 5,276.67 vs tax 5,483.33); overrides; category/account
/return validation; form parsing and derivation; CSV parsing; stdio:
filtered catalog, mapping, refusal, summary, all-or-nothing import.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
The close zeroed every revenue and expense account's all-time movement,
so closing a period after later entries were posted swept those too:
close January in March and February's and March's income landed in
January's closing entry. The preview had the same bug and never showed
where the net went. Now:
- close_period_to(id, to) zeroes balances as of the period end; entries
dated later stay open for their own period. Periods must close in
order (LedgerError::CloseOutOfOrder): a later close has already swept
the earlier period.
- CloseTo::Members: for a partnership (multi-member LLC) the net goes to
each member's capital account by share, to the cent, the last member
absorbing rounding, which is what K-1 capital accounts track.
CloseTo::RetainedEarnings (3999) stays the default; close_period is
shorthand for it. books.close_period picks Members when
wanderbooks.toml lists members.
- The journal records the close target; replay re-derives the closing
entry and now compares every line with the journal, not just the id,
so a change to closing math can never silently rewrite history.
- The tool's preview is the real close run on a clone of the ledger
(Ledger now derives Clone), so preview and post can't disagree.
- Members' equity: closing entries into a capital account are income,
not contributions. Balance sheet for a partnership: capital accounts
(with allocated earnings), then only unallocated earnings —
"Undistributed earnings, prior years" if any, and this year's unclosed
net income (loss). periods::allocate is shared by the close and the
statement.
Tests: January closed after February is posted sweeps exactly Dr 4000
2,500 / Cr 6100 800 / Cr 3999 1,700 (mutation-checked: the old code gives
3,500/120/800/2,580); out-of-order close refused; a partnership close
splits 666.67 into 333.34/333.33 with no 3999, and the members' equity
statement reads correctly before and after; store replay of a members
close (reopen, rebuild, verify); partnership and corporate balance sheet
layouts; stdio close preview equals the posted lines.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Every report a CPA expects, laid out the way US small-business books
read (QuickBooks as the reference):
- Exports: books.export gains general_ledger (by account, running
balances, splits), general_journal (the entry-ordered listing, which
the CPA package used to mislabel "general ledger"; alias journal),
members_equity, and trial_balance as of a date, in xlsx/csv/json, and
PDF for all five statements (P&L, balance sheet, cash flow, trial
balance, members' equity). books.trial_balance takes as_of.
- CPA package: every statement as PDF and XLSX, plus the general ledger
and general journal, all for the fiscal year to date.
- Layout (ledger-import::report): multi-column statements (Total;
Debit/Credit; one column per member plus Total), "$" on subtotals and
totals, a rule above every sum (none over an empty section), a double
rule under statement totals, zero as 0.00, negatives in parentheses
with the closing paren hanging so decimal points align.
- Terms: "Net income (loss)"; for a multi-member LLC, "Members' equity",
member contributions and distributions named in the cash flow, and the
balance sheet splitting retained earnings (the Retained Earnings
account plus earnings not yet closed from earlier years) from the
fiscal year's net income (loss); the cash flow's "Adjustments to
reconcile net income (loss) to net cash from operating activities" and
"Net increase (decrease) in cash".
- PDF: Inter replaces the typst-assets serif fonts (bundled, SIL OFL 1.1,
license in fonts/; from the official v4.1 release), centered title
block, column-header row, full-width rules, footer "Accrual basis ·
Prepared <date> · Journal seq N" with page numbers. Amounts on total
rows stay regular weight so bold figures can't leave the decimal
column. typst-assets dependency removed.
- XLSX: centered title block, header row, Excel accounting formats with
"$" attached on sums, general ledger and general journal workbooks.
- Config: wanderbooks.toml [[company.members]] (name, share "50%" or
"0.5", capital_account; shares must total 100%) and [books]
accounting_basis (accrual | cash).
- Core: RETAINED_EARNINGS_CODE names the "3999" that period close uses.
- Fix: "today" is local time, not UTC; in US evenings UTC is tomorrow,
so reports defaulting to "through today" included the next day and
footers carried the wrong date.
Tests: layout (currency and rule placement, retained earnings vs. this
year's net income for a member LLC, footer text); exact template data;
deterministic PDFs; config parsing (members, shares, basis); stdio:
trial balance as of, February general ledger (beginning 1,004.00, splits,
ending 1,003.50), members' equity (contributions 1,000.00, net income
3.50, ending 1,003.50), members' equity PDF, the CPA package's ten files.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Zero warnings from `cargo clippy --workspace --all-targets`, which is now
a hard rule rather than "clean except pre-existing":
- ChartOfAccounts::add takes the Account it registers instead of eight
loose parameters (too_many_arguments); Ledger::add_account builds it.
Same validation, same errors.
- close_period tool: collapse the nested if-let into a let chain.
- iif.rs docs: the IIF layout example shows tabs as `\t` instead of
literal tab characters (tabs_in_doc_comments).
- Tests: drop an unused binding; assert! instead of assert_eq! against a
literal bool.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
The engine only had life-of-ledger P&L and balance sheet totals, so every
export labeled with a date range or as-of date (PDF, XLSX, CPA package)
printed all-time numbers under that label. Core now has:
- profit_and_loss_for_period(start, end, class?) and
balance_sheet_as_of(as_of), each with a line per account
(StatementLine: code, name, normal-side amount) and exact totals.
- Ledger::closing_entry_ids(). Period statements exclude closing entries.
A close (Dr revenue / Cr expense / net to Retained Earnings, dated at
period end) moves earnings; it doesn't earn or spend. Counting it made a
closed period's P&L read as break-even, and made the cash flow show zero
net income plus a fake "owner contribution" to Retained Earnings. The
as-of balance sheet keeps closing entries: after a close the earnings
belong in Retained Earnings, not current earnings.
Tests: tests/statements.rs, a two-month fixture with every expected number
computed by hand (Jan NI 1,700; Feb 880; balance sheets on four dates; a
closed January still reporting 1,700 and a cash flow with one financing
line). Mutation-checked: dropping the closing exclusion fails it (0 vs
1,700). Properties: period P&Ls partition a year at any split, and a
range's net income equals the change in current earnings across it, with
A = L + E on both dates.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
swaitsandClaude Opus 5.5