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 SQLite cross-check rebuilt entries by id and assumed no gaps, but
drafts aren't projected until posted: a draft #8 before a posted #9 made
the server refuse to start. Gaps are now held with empty drafts (which no
report counts), and a projection that can't be read back counts as drift
to heal, not a reason to refuse to start.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
books.show asks the viewer to open an entry, an account register, a
report (dates, month/quarter/year columns, prior-period or prior-year
comparison), a document, a search, or a page. The request lives outside
the books (runtime dir, keyed by data dir, written atomically); the
viewer watches it beside the journal and applies books before
navigating. 66 tools.
Site: the dashboard is the hero again; 'Here's what using it looks like'
shows the session beside the viewer, ending in books.show; the cash page
replaces the repeated overview lower down.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Store::verify compares the whole SQLite projection, every table row for
row, against a fresh projection of the journal; verify_and_heal rebuilds a
drifted database (keeping the old file) at every server start and via the
new books.verify tool, which also re-hashes every blob. The GUI checks the
server's database read-only and every stored file, and shows the result.
rebuild() also drops stale WAL/SHM files.
site/: the wanderbooks website (just site, just publish). install.sh:
OS detection (Windows points to WSL2), C compiler and git checks,
WANDERBOOKS_REPO. Windows: no directory fsync off Unix; .exe-aware lookup.
Repo justfile: check, build, install, demo, site.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
egui/wgpu app for owners and their accountant: Overview, Cash, Profit,
Transactions (with rendered receipts and journal history), Reports
(statements with interval columns, comparisons, drill-down), Accounts,
Documents, Company, Journal; Ctrl+K palette; back/forward; light/dark.
Follows the journal live (~30 ms from write to screen). --demo opens a
deterministic demo company, also used for screenshot tests.
Engine: ledger-store Snapshot (read-only, incremental, tolerant of a
half-written tail); ledger-core analysis (intervals, balance series,
P&L by interval, cash flows); ledger-config extracted from ledger-mcp
with the full company profile and cash_accounts.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
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 statement export rendered life-of-ledger totals under whatever date
range or as-of label was asked for, and the P&L and balance sheet XLSX
were totals-only. Now:
- books.profit_and_loss / books.balance_sheet and the csv, json, xlsx,
pdf exports and CPA package all use core's profit_and_loss_for_period
and balance_sheet_as_of, with a line per account. The tools keep their
totals and add revenue/expense/asset/liability/equity account lines.
An omitted start is the first posted entry, never "0001-01-01".
- ledger-import::report lays a statement out once (section, line,
subtotal, total) for every renderer, with one exact amount formatter:
thousands separators, negatives in parentheses, no floats. XLSX keeps
numeric cells with an accounting number format, named sheets, company
header, totals with borders; the trial balance gains its totals row.
- ledger-mcp reads wanderbooks.toml (next to --data-dir, or
--books-toml): company name for headers, fiscal_year_start for the CPA
package's fiscal year to date (end derived; Feb 29 rejected), and
[books] receipt_threshold, which the server had been ignoring.
config.json's receipt_policy still wins when set. New dependency: toml
1.x (already in the lockfile via another crate).
- Store::journal_seq(); every report notes the journal seq it reflects.
Tests: company.rs unit tests (fiscal years incl. a July start, scaffold
parsing, bad settings); report.rs formatting tests; an MCP stdio test with
--books-toml (threshold 5.00 enforced, February-only P&L with account
lines, start defaults to the first entry, as-of balance sheet).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
Posted entries stay immutable (R-3), but their evidence can now change the
same way the ledger does: by appending events, never by editing or
deleting. New R-13a.
- books.unlink_receipt {attachment_id, reason} journals receipt.unlinked
and leaves the receipt filed, unlinked. The receipt policy holds: an
entry that requires a receipt can't lose its last one (structured
receipt_required error), so a replacement is attach-new, then
unlink-old. Drafts and reversals are exempt, as at posting.
- books.withdraw_attachment {attachment_id, reason} journals
attachment.withdrawn for an unlinked receipt or a filed document: hidden
from list_receipts (unless include_withdrawn), never linkable again. The
blob stays in the store, hash-verified and readable.
- link_receipt now refuses an already-linked or withdrawn attachment.
Before, re-linking silently moved a receipt off a posted entry,
bypassing the policy; evidence now leaves an entry only through a
recorded unlink. dispose_asset checks its receipt ids before posting
instead of after.
- Schema v5 adds attachments.withdrawn_at/withdrawn_reason; existing
stores migrate on open and replay rebuilds the projection.
Tests: store test (errors, reopen, rebuild, verify, journal history) and
an MCP stdio test (policy refusal, replace flow, withdraw, listings,
under-threshold unlink). Dry-run and live use on the Wanderland Labs books:
8 migrated .eml attachments swapped for their PDF renders, trial balance
unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu
swaitsandClaude Opus 5.5