wanderbooks/docs/testing.md

Testing strategy

How wanderbooks knows its books are right. Strongest oracle first: a test's worth is where its idea of "correct" comes from, not what it runs. Formal proofs are in docs/verification.md; the authorities every rule comes from are in docs/spec/. Every crate is covered: ledger-core, the store, import, config, and MCP in full; the GUI where it computes and writes numbers (its view model and formatting) and in its read-only promise.

Layers

Layer	Oracle (rank)	Where	Command	Runtime	Gates
Spec-derived examples	written specs with sources (1)	tests/spec_*.rs, invariants.rs, statements.rs, assets.rs, ...; the store's tests/spec_store.rs (written blind, from its specs only)	just check	seconds	every change
Regressions	the bug, named (1)	beside the code they cover, *_regression/named for the defect	just check	seconds	every change
Compatibility contracts	journals written under older rules must open, and replay to the figures their version computed (1)	ledger-store/tests/store.rs (books_written_under_older_rules_still_open; books_an_earlier_version_wrote_open_to_its_figures over tests/fixtures/old-books: books main 188c90ea wrote, with main's own figures in expected.json, in the writer and the viewer; every_figure_over_old_books_is_computed_or_refused); ledger-mcp/tests/hostile_args.rs old_books_answer_every_tool; ledger-gui/tests/old_books.rs	just check	~30s	every change
Properties	laws over all inputs (2)	properties.rs, spec_*.rs, kernel_bridge.rs	just check	seconds	every change
Metamorphic	scaling, reversal, ordering invariance (2)	spec_reports.rs	just check	seconds	every change
Refusal law (store)	a refused command never reaches the journal, an accepted one always does; the live ledger equals its journal's replay in every part, and the books reopen to it (2, 3)	store.rs refused_commands_never_reach_the_journal	just check (STORE_CASES=5000 deeper)	~20s	every change
Fault injection (store)	a full disk or a cut-off append leaves whole, openable books (1)	ledger-store/tests/faults.rs, store.rs (power_loss_at_any_byte_of_the_last_append_is_recovered)	just check	~5s	every change
Concurrency (store)	a viewer reading while the books are written sees only whole books, never a false "differs" (2)	ledger-store/tests/concurrency.rs	just check	<1s	every change
Model-based stateful	the Lean state machine, transcribed (3)	tests/model.rs	just check	~3s	every change
Differential: Decimal vs i64	the kernel at two types (3)	kernel_bridge.rs	just check	<1s	every change
Differential: GnuCash	another implementation, adjudicated (3)	tests/oracle_gnucash.rs, oracle/gnucash/	just oracle	~2 min	weekly
Formal proofs	Kani (bounded) and Lean (unbounded)	src/proofs.rs, verify/lean/	just prove (48 harnesses and Lean), just prove-slow (the 8 in the justfile's kani_slow, each under its own 30-minute cap)	prove ~5 min and prove-slow ~8 min at four jobs on a quiet laptop (each ~25 min under heavy load; docs/verification.md, "Running it")	weekly (CI runs both)
Fuzzing	crash, hang, broken books (4); for fuzz_store_replay (validly chained journals with fuzz-chosen events): books that open must verify, and the viewer must accept exactly what the writer does	fuzz/fuzz_targets/, corpora in fuzz/corpus/	just fuzz <target> <secs>	10 min each	weekly
Miri	undefined behavior in our use of dependencies (4)	the core's unit, bridge, invariant tests (the exhaustive calendar walk aside)	just miri	~4 min	on demand
Golden	tests/golden/fixture_company.json (5)	invariants.rs	just check	<1s	every change
Benchmarks	a baseline (6)	ledger-core/benches/books.rs, ledger-store/benches/store.rs	just bench	~2 min	none (no budget, by decision)
Mutation	can the tests fail?	ledger-core (2026-10-13: 1,011 caught + 13 timeouts of 1,024 viable, 0 missed)	just mutants	~3 h	weekly
Mutation (store)	can the tests fail?	ledger-store (2026-10-13: 357 caught + 1 timeout of 365 viable, from 82%; three of its seven survivors then killed; four equivalent left: sort_value's two arms, OpenFlags `	vs^`, the long form of a sweepless close)	just mutants-store	~12 min
Mutation (import)	can the tests fail?	ledger-import (2026-10-13: from 91 of 171 (53%) to 208 of 239 viable on the full run; the 31 survivors (XLSX layout, borders, alignment, exact-text grouping, IIF transliteration, tax-summary optional sections, day-equals-month dates) then killed by targeted tests, re-run clean but one: a blank amount cell written unbordered on an unruled row, invisible, so equivalent; 2026-10-19, the first scheduled run in CI: 375 tested, 327 caught, 42 unviable, 6 missed (the tax-basis rule marks, a heading's alignment, the totals row's blank cells, and that blank cell, after all: a ruled row writes it, an unruled one writes none), all six then caught by rule_marks_match_their_notes, asset_register_xlsx_headings_and_totals_rule and xlsx_missing_amounts_are_cells_only_on_ruled_rows, each checked against its mutant by hand)	just mutants-import	~2 h	weekly
Mutation (roles, reload)	can the tests fail?	control roles and settings reload (2026-10-15, targeted: the role paths in ledger-core 30 caught of 30 viable; ledger-store's journaling and replay of role.assigned 20 of 20; ledger-mcp settings, reload, roles, digest 28 of 28)	cargo mutants -F on those functions (see the commit)	~15 min	with the crate's weekly run
Mutation (config)	can the tests fail?	ledger-config (2026-10-14: 55 caught of 55 viable)	just mutants-config	minutes	weekly
Mutation (MCP)	can the tests fail?	ledger-mcp (2026-10-14: from 197 caught + 5 timeouts of 328 viable (62%) to 314 caught + 2 timeouts of 331; of its 15 survivors, five then killed by targeted tests (the settings file beside the books, year earnings with an open period and with last year's partial close, year 1, a failed flush), one dead guard removed (profit_and_loss_by_class skipping placeholders, which never take postings), nine equivalent: money rescaling an amount already at two places, the lock wait's deadline instant, year_earnings starting the day the year starts either way, the bank import's rehearsal sides (a line's side can't make a draft refuse) and its zero-amount side (zero rows are dropped by the parser), a disposal's zero gain adding zero, and the CPA package index summing debits instead of credits (entries balance))	just mutants-mcp	~1 h	weekly
Mutation (GUI)	can the tests fail?	ledger-gui view model and formatting (2026-10-14: 140 caught of 176 viable on the full run, then 92 of 99 on a targeted rerun of the money paths after new tests; of its 7 survivors, one then killed by a test (burn over exactly one month, confirmed by a rerun of compute_kpis's 48 mutants), two dead arms removed (parties' bill arms: the ledger tags bill entries with their vendor, which wins), four equivalent: an entry's debits vs its credits (they balance), the three-month burn boundary (both paths give 3), burn over zero covered months (only when the first entry is after the window, which then holds no loss), and compact's sign test at zero (zero prints "$0" unsigned either way))	retired 2026-10-18 (owner: it crushed the machine; for the viewer, test its two musts directly: it never writes the books, tests/read_only.rs, and every figure it shows is the engine's, tests/view_model.rs)		never

CI: .github/workflows/check.yml runs just check on every push; scheduled.yml runs proofs, the oracle, fuzzing, and mutation weekly. Mutation is split into shards, one job each (just mutants-mcp 3/16 runs the fourth of sixteen), because GitHub stops a job at six hours and a whole crate takes longer on its runners (2026-10-19, the first scheduled run: the core and MCP runs were stopped at the limit). Test timeouts are three times each run's own baseline, never under the recipe's floor, so a slower runner doesn't report false timeouts. The viewer has no mutation job.

Seeds and failure databases: proptest's *.proptest-regressions files are checked in and replay on every run. The GnuCash oracle's books come from fixed seeds (SEED in oracle_gnucash.rs). Fuzz corpora live in fuzz/corpus/<target>.

Golden review: fixture_company.json is hand-verified (docs/oracle.md, Layer 1). The van depreciation golden was replaced on 2026-10-13 by a hand computation (van_schedule_is_the_hand_computed_one) after every row was checked against it.

P0 guard rails (2026-10-16)

Laws added with P0 (plan/served.md) and its review, each with the test that would fail if it broke:

Law	Test
Books from a newer wanderbooks are "newer", never "corrupt", from the writer, the viewer and the server; damage stays corruption (rules.md B-27)	ledger-store tests/format.rs (old_reader_gets_newer_journal, damaged_journals_are_still_corrupt); ledger-gui tests/newer_journal.rs; ledger-mcp tests/startup.rs
A line the gate refuses is called newer only once the next line's prev checks its hash; a last line is "newer or damaged"	a_damaged_line_that_looks_newer_is_corrupt_when_the_next_line_checks_it, an_unreadable_last_line_is_reported_as_newer_or_damaged, a_newer_line_the_next_line_chains_onto_is_newer_and_intact (the message vouches for that line only)
The envelope and its hash are frozen across formats: a next line in a newer format (a float, a string seq, keys of its own) settles by its prev alone, never as corrupt; a key beside the envelope is newer, never dropped, and still checked through; a refused line followed by an unreadable one is "newer or damaged"	format.rs a_newer_format_frames_its_lines_its_own_way, an_unknown_envelope_key_is_newer_and_checked_through, a_refused_line_followed_by_a_garbled_line_is_unverified
The writer and the viewer read bytes alike: a line that isn't UTF-8 is corrupt to both; an older version never repairs (truncates) newer books	a_line_that_is_not_utf8_is_corrupt_for_the_viewer_and_the_writer, an_old_reader_never_repairs_newer_books
A newer format is newer whatever its features look like; a blank line is damage to the viewer as to the writer	format.rs a_newer_format_is_newer_whatever_its_features_look_like; a_blank_line_is_corrupt_for_the_viewer_and_the_writer
A request that panics stops the server: every later request, on every session, is refused	server.rs a_request_that_panics_stops_the_server
No input reaches a panic (each would stop the server for every session): every tool with arguments generated from its schema and made hostile (wrong types, u64::MAX, decimals of 30+ digits or absurd exponents, dates like 0000-00-00, 99999-12-31, +262142-12-31, 2026-02-30, periods like 999999-01, control and format characters, long strings), every resource URI generated; the inputs that once panicked, pinned; after each property the server restarts and the books reopen (a call a command accepts but replay refuses would brick them); every tool and resource over every old book (rules.md B-28)	ledger-mcp tests/hostile_args.rs hostile_tool_arguments_never_stop_the_server (with a floor: most calls reach a tool, some succeed), hostile_resource_uris_never_stop_the_server, inputs_that_once_panicked_are_refused_or_answered, old_books_answer_every_tool; MCP_CASES and OLD_BOOKS_CASES (default 3 per tool per book) set the cases
Dates are in 0001-01-01 through 9999-12-31 and amounts at most a line's, for every new command; replay accepts every line an earlier version accepted (each bound has its pair: the command refuses past it, the replayed old line is accepted); a figure derived past exact arithmetic or chrono's calendar is refused, never a panic; a recurring run makes at most 1,000 drafts (rules.md B-28)	ledger-core tests/spec_bounds.rs, calendar.rs tests, plans_at_the_edges_are_computed_or_refused, intervals_reach_chronos_last_day, a_vendor_part_is_scaled_exactly_or_refused, the share_property cases; ledger-store tests/bounds.rs, tests/store.rs (the old-books tests); server.rs periods_are_a_year_and_a_month, dates_are_four_digit_years_and_real_days
Opening the books changes nothing until every complete line passes in memory (chain, gate, first line, replay); the viewer applies the writer's first-line rule (rules.md B-27)	format.rs a_bad_complete_line_before_a_torn_tail_leaves_the_journal_as_it_was, the_first_line_is_store_created_for_the_viewer_and_the_writer; fuzz_store_replay (the first line varies)
UTF-16 text without a byte-order mark is scanned like any text; a refused books.set_w9 marks no file; a refused resource read never echoes a TIN	tin_files.rs (tests) utf16_text_without_a_byte_order_mark_is_scanned_either_way_round, a_refused_set_w9_never_marks_its_file, unit test only_nul_interleaved_bytes_read_as_utf16_without_a_mark; spec_vault.rs resource_refusals_never_echo_a_tin
idempotentHint only where a repeat with the same arguments leaves the journal and the vault as they were; every tool's hints pinned in one table	spec_vault.rs idempotent_tools_change_nothing_when_repeated; annotations_complete
books.settings lists every receipt-required and exempt account, uncut; a fresh company is "a new company"; the lint catches just however it ends and where the books are	mcp_stdio.rs every_receipt_account_left_out_of_the_connect_text_is_in_books_settings; handbook.rs a_fresh_company_is_a_new_company; tool_text_lint_catches_helpers_and_locations
A file with full TINs is never written to a path (handed over instead, D-29), and never filed into the books: every file the server read or wrote with TINs (from any session, after a restart, out of a CPA package), by every filing tool	mcp_stdio.rs tin_bearing_files_are_refused_when_given_back_to_be_filed; spec_vault.rs a_package_is_handed_over_and_never_written; tin_files.rs (tests) a_tin_bearing_file_is_refused_from_every_session_and_after_a_restart; unit test a_recorded_tin_file_is_refused_by_every_reader_of_the_registry
Text filed into the books is refused when it holds a TIN the vault keeps (nine digits, 3-2-4 by hyphen, space or dot, 2-7 by hyphen or space, anywhere) or a stand-alone printed SSN or EIN (123-45-6789, 12-3456789), and only then: a bank export (routing numbers, long references, a date next to an amount) and a longer number holding an SSN shape go in; a locked vault leaves the printed shapes (rules.md B-26)	tin_files.rs (tests) text_with_a_vault_tin_or_a_printed_one_is_refused_and_a_bank_export_is_not; unit tests text_holding_a_vault_tin_is_refused_in_every_rendering, a_printed_ssn_or_ein_is_refused, a_longer_number_holding_a_tin_shape_passes, an_ordinary_bank_export_passes, binary_bytes_are_not_scanned
Filing is no TIN oracle: text with more than two TIN-shaped numbers ending in a known TIN's last four (the books' TIN and W-9 facts, then the vault's own) is refused before the vault is opened, byte for byte alike whether one is the vault's TIN or none is, the vault open or locked, by every filing tool; one or two such numbers are compared against the vault, one number written many ways counts once, and other last fours never count (rules.md B-26)	tin_files.rs (tests) text_probing_for_a_tin_is_refused_alike_by_every_filing_tool; unit tests text_probing_for_a_tin_is_refused_alike_whether_or_not_it_holds_it (the vault never opened for a probe), one_or_two_candidates_are_compared_against_the_vault
The connect text fits its budgets, its lead stands alone, it states the receipt rule enforced (exact threshold in the base currency, required and exempt accounts, reversals) and the parties rule in force, and the company name can't break it (control and format characters)	handbook.rs instructions_budget, a_typical_company_gets_the_whole_connect_text, the_company_name_is_one_plain_line; receipt_policy.rs the_rule_told_is_the_rule_enforced, a_long_or_odd_account_list_stays_short_and_plain; a new session is told the settings in force: a_new_session_is_told_the_settings_in_force
No text the agent is given (whole tool JSON, resources, connect text, handbook, every error template and refusal) points at files, git, GitHub, repo docs, flags or helper commands; descriptions fit 700 characters (listed exceptions, P5; and what git itself said of a failed backup, which books.backup passes on to the human as git said it, its paths hidden)	tool_text_lint, tool_descriptions_fit_700_characters; ledger-core an_unknown_year_threshold_is_never_guessed
Every tool is annotated (openWorldHint false on all but books.back_up_now), and the read-only hint is true in behaviour (journal, every data-dir file's contents but ops/, the viewer's side channel for books.show, which is not the books; the database's rows, the vault and the settings unchanged)	annotations_complete; spec_mcp.rs read_only_tools_change_nothing (checked on every call in Mcp::tool)
A bare (or empty-since) digest covers this month so far, on any day of it, as the server counts it (the stdio test reads the server's own month, and starts over if it turns)	a_bare_digest_covers_this_month_so_far; mcp_stdio.rs digest_resource_bare_reads
The handbook: every section, "all" in order, the schema names every id	handbook_sections_render_the_rule_in_force, the_whole_handbook_is_every_section_in_order, mcp_stdio.rs handbook_tool_and_resources_over_stdio

P0 mutation testing (2026-10-16)

Every mutant cargo-mutants makes in the final P0 diff (jj diff -r 'main..@', --in-diff), per crate, against that crate's tests (the recipes' settings: STORE_CASES=64, MCP_CASES=16, no shrinking; the viewer against its lib tests and newer_journal). Final run:

Crate	Mutants	Caught	Timeouts	Unviable	Missed
ledger-mcp	296	208	3	71	14 (equivalent, below)
ledger-store	73	58	0	12	3 (equivalent, below)
ledger-config	35	35	0	0	0
ledger-gui	9	6	0	3	0
ledger-core	1	1	0	0	0

(ledger-cli's change makes no mutant.) After the filing scan's probe bound (rules.md B-26), tin_files.rs alone was run again against the whole P0 diff: 74 mutants, 74 caught, among them every mutant of the bound (probes made true or false, > made >=, == or <, the last four's % made / or +, here and for the vault's own last fours) and of the shared tin_shaped scan. The three MCP timeouts are resolved without its hop limit (< 40 made true, the count made to go down or stay 0): a link loop then never ends, so the tests can't pass. The first run missed 36 in the MCP server, 5 in the store, 4 in config and 1 in the viewer. Each was killed by a test of the law it broke, removed by simpler code, or is equivalent:

• Killed (MCP). A section's title is its heading (a_title_is_the_heading_text; over stdio the handbook tool titles a section by its heading and "all" as the whole handbook, handbook_tool_and_resources_over_stdio). A .jpg or .jpeg W-9 was taken (every_w9_file_type_is_taken); P2 slice 5 judges the W-9 by its first bytes, not its name, so that mutant's code is gone (the test now checks each type by its bytes). The waker wakes: a request pending until another thread wakes it completes (a_request_that_waits_is_woken_and_completes). Three more were killed by tests of the import roots and their walk (a refused default root dropped, never fatal; a folder swapped for a link or a pipe never walked through; a read failure naming its kind, never the path): P2 slice 5 removed books.import_local_file and the import roots, and those tests with them. resolved follows 40 links, as the kernel does, and no more (resolved_follows_forty_links_and_no_more). A file is saved only to a new file in a folder that exists, and a missing folder or a taken file is refused as such, never as a failed write (a CPA package test, and the_w9_file_goes_to_the_vault_never_the_documents; P2 slice 6 took the paths out of the tools, and the package test with them). The CPA package marks only its own TIN files: a statement it carries still goes in afterwards (a_tin_bearing_file_is_refused_from_every_session_and_after_a_restart). An unreadable TIN-file registry refuses every file (an_unreadable_registry_refuses_every_file). Text that isn't UTF-8 is scanned when its type is text/*, a JSON type (/json, +json) or its name says text (encodings in the tin_files.rs unit tests).
• Killed (store). read_journal_and_format returns every line and the format in force (read_journal_and_format_gives_every_line_and_the_format). The newline that ends a line is no part of it, so the viewer's words about a damaged line are the writer's, opening and following (the_viewer_and_the_writer_say_the_same_of_a_damaged_line; it kills snapshot.rs raw.len() - 1 → / 1).
• Killed (config). The short rule (no codes listed) counts each kind of account, whichever kinds there are, and says nothing of accounts when there are none (the_short_rule_counts_each_kind_of_account); a code of exactly 12 characters is kept whole (a_long_or_odd_account_list_stays_short_and_plain).
• Killed (viewer). The journal page tells a journal.format_set line (a_format_this_version_reads_opens_and_the_journal_page_tells_it).
• Simpler code (MCP). inspect compared canonicalize with resolved; only a race between those two calls could make them differ, and the file read was the checked one either way. It now places an existing path by canonicalize itself. read_checked refused by the file's size before reading, so its read limit (limit + 1) was only reached by a file growing during the read; the read's limit is now the one check (the 25 MiB upload test kills + 1 → * 1). openat failed on fd < 0, now on fd == -1, as openat(2) specifies. (inspect, read_checked, the openat walk and that 25 MiB test were removed with the import roots in P2 slice 5.)
• Equivalent (MCP, all 14 missed; the walk and its stubs were removed in P2 slice 5). ^ for | in the open flags (six: the walk's first step, each folder's two, the file's two, and openat's O_CLOEXEC): O_RDONLY is 0 and O_DIRECTORY, O_NOFOLLOW, O_NONBLOCK, O_CLOEXEC are distinct bits, so a ^ b is a | b. & for | in the first step's O_RDONLY | O_DIRECTORY: it opens / read-only either way, and / is always a folder. The off-Unix stubs (Protected::inodes, five mutants; open_walk; hard_linked) are not compiled on Linux, so their mutants change nothing here.
• Equivalent (store, all 3 missed). Snapshot::journal_format and Store::journal_format returning the default: this version reads format 1 with no features only (SUPPORTED_JOURNAL_FORMAT 1, KNOWN_FEATURES empty), and that is the default, so no journal it opens has another format in force; the first format 2 or feature makes them killable. Store::open setting aside a torn tail when complete <= raw.len(): repair_torn_tail re-reads the journal under the writer lock and does nothing when it ends in a newline.

Round 3 (2026-10-17)

cargo mutants --in-diff on this round's changes (the diff from the round-2 stack to round 3), per crate, output under ~/.cache/wanderbooks/mutants/p0-r3-<crate> (MCP_CASES=16, STORE_CASES=64, PROPTEST_MAX_SHRINK_ITERS=0):

Crate	Mutants	Caught	Missed, then killed	Equivalent	Timeouts	Unviable
ledger-core (tests of core and store)	63	53	3	1	0	6
ledger-store	40	34	0	0	2	4
ledger-mcp	85	63	5	1	0	16
ledger-config (a doc comment only)	0

• Killed (core). replay_add_line_fx's size check (> to == or >=) and validate_recurring's (> to >=): a line, base or foreign, added or replayed, and a template line may be exactly the line limit (spec_bounds.rs the_bound_is_the_line_limit_itself).
• Timeouts (store, counted as caught). run_recurring's cap (> to == or <): without it, a monthly entry run through 9999-12-31 writes some 95,000 drafts, which is what the cap is for (bounds.rs a_recurring_run_has_an_end).
• Killed (MCP). text_of's byte-order-mark arms: text with a mark and no NUL byte at all (full-width digits, CJK) is still read as UTF-16 (utf16_with_a_mark_is_read_whatever_it_holds); its NUL-stripped reading (!= to ==): NULs scattered in text hide no TIN (nuls_scattered_in_text_hide_no_tin); nul_interleaved's eighth (* to +): half NUL on one side and three of sixteen on the other is not UTF-16; redact_value's array arm: a TIN inside an array of an error's data is masked (redact_error_masks_every_tin_in_the_message_and_data).
• Equivalent. k1::share_property returning early on whole <= 0 && total <= 0 instead of ||: whole is min(pool, total) with both sums of non-negative amounts, so the two differ only when whole is 0 and total positive, where the computation goes on to split 0 into zeros, the early answer. redact_value's guard has_full_tin(t) replaced by true: redact_full_tins returns its input unchanged when it finds no run, exactly when has_full_tin is false, so the guard only saves a copy.

Round 4 (2026-10-17)

cargo mutants --in-diff on this round's changes (replay restored to main's rules, derived figures checked, the old-books contracts), per crate, output under ~/.cache/wanderbooks/mutants/p0-r4-<crate> (MCP_CASES=16, OLD_BOOKS_CASES=1, STORE_CASES=64, PROPTEST_MAX_SHRINK_ITERS=0; the GUI's old-books test over the edge books only, OLD_BOOKS_ONLY=x_draft_max_lines,x_schedule_chrono_end,..., since asset_long_life alone takes three minutes a run):

Crate	Mutants	Caught	Missed, then killed	Equivalent	Timeouts	Unviable
ledger-core (tests of core and store)	176	153	6	3	0	14
ledger-store	12	11	0	0	0	1
ledger-mcp	81	13	5	1	0	62
ledger-config	7	7	0	0	0	0
ledger-gui	221	47	137	11	7	19

• Killed (core). name_payroll_parties (replaced by Ok(()), and == to != in merging one employee's lines): a payroll entry names its employees, each with their net pay, live and on replay (spec_parties.rs a_payroll_entry_names_the_employees_it_paid); entry_flow's across_left -= take (+=, /=): across is used up in order (entry_flow_takes_across_in_order_until_used_up); share_target's debit filter (== to !=): an unbalanced draft moving no money splits over its debits (a_share_target_without_money_is_the_debits); resolve's capital debit sign: members' derived shares net their capital lines (derived_member_shares_net_their_capital_lines). These were in code this round touched only to make it checked; the core and store tests never reached them (the MCP tests did).
• Killed (MCP). lines_settled (whole and in parts): an empty, an unbalanced and a Decimal-overflowing draft are not settled, a balanced draft and a posted entry are (server.rs settled_lines_are_posted_or_balanced_drafts).
• Killed (GUI). The pages' display of what can't be computed and of the edges was barely asserted: new tests in tests/edges.rs and beside the pages (test_support.rs renders a page headless and reads its painted text and shapes) cover the runway and "coming up" on the cash page, the balance chart's labels and hover, an entry's totals (balanced, out of balance, too large to total), a party's span and monthly chart at chrono's edges, a split entry's part, the register's reconciliation colours, the company page's cards, the report range, prior period and column limit, and the transaction row. The rerun (p0-r4-gui-rerun) left only the equivalents.
• Equivalent (GUI, 11). party_span's < to <= (twice): they differ only at year 0, which chrono holds, so the fallback is never taken. The asset notice's > to >=: with nothing unposted both amounts are 0 and nothing is pushed. occurrences_from's five arithmetic mutants: each leaves k0 a lower bound on the first occurrence on or after from, so only the walk's length changes. The cash forecast's > to >=: a zero amount added to inflow instead of subtracted from outflow. The company page's total.is_zero() guard: a schedule's total is always positive. Its recurring total's == to !=: a template always balances, so its credits sum to its debits.
• Equivalent. entry_flow's filters v > 0 to >= 0 and v < 0 to <= 0: they only add zeros to a sum. split_first's weights.is_empty() || total.is_zero() to &&: every weight is positive (a percent above 0, a member's share checked above 0), so a non-empty list never sums to zero. lines_settled's side filter l.side == s to !=: it swaps which sum is called debits, and the comparison and the overflow refusal are symmetric.
• A real defect found while writing these tests: the depreciation true-up named its final month with chrono's %Y, which signs a year past 9999 ("+10004-03"), while the lines don't, so an asset whose life ran past 9999 never trued up and could depreciate past its salvage (spec_replayed_extremes.rs a_life_past_9999_trues_up_to_the_cent).

P1: the books keep how they are kept (2026-10-17)

Law	Test
Replay is pure: after any sequence of settings, convention, decision, open-item, template and approval commands, valid or refused, the live store, the store reopened from its journal and the viewer's snapshot hold the same settings and conventions, and the store verifies (database row for row)	ledger-store tests/settings.rs settings_replay_is_pure (proptest, 512 cases per check; 2,000 by hand, release, passed)
Settings need journal format 2: books this version made declared it as they were created, so a change journals only itself; a change to what is set journals nothing; books in format 1 refuse a change (nothing journaled) until their format upgrade, then make it after the one declaration; refused changes journal nothing	a_change_needs_journal_format_2, refused_changes_journal_nothing
Approval rules block nothing until enforced; then an entry a rule covers posts only once its approver approved it as it stands	approval_rules_off_by_default; ledger-mcp spec_kept.rs approval_rules_through_the_server
A template drafts exactly, odd cents by largest remainder, its slots named by each draft, all or nothing	templates_draft_exactly_or_not_at_all, template_slots_take_the_account_each_draft_names, templates_draft_through_the_server, core splits_are_exact
Books written under P1 open to the same record forever	books_written_under_p1_open_to_their_record (fixture old-books/p1_record, also in every old-books test of the store, the viewer and the server)
A settings file imports exactly, reads as it did, and an export round-trips; a masked EIN never imports	ledger-config codec unit tests, tests/codec_props.rs exports_round_trip (512 cases), ledger-cli the_toml_and_its_examples_import_and_round_trip
Moving settings in: set refused before, the preview records nothing, the file never read after (not even to start), an import that reads differently or loses the vault key refused, the EIN only ever masked	spec_kept.rs a_settings_file_moves_into_the_books, an_import_that_reads_differently_is_refused, an_import_needs_the_vault_key_on_the_command_line
books.start fits in 8 KB and says what it cut	start_fits_in_8_kb
Values are canonical; no full TIN but the company's EIN; settings hold together; replay takes shapes	core settings::tests
Every new tool on the happy path, schema-checked; read-only tools change nothing; idempotent tools repeat as no-ops	spec_mcp.rs inv1_*, read_only_tools_change_nothing; spec_vault.rs idempotent_tools_change_nothing_when_repeated
The connect text names books.start in its lead and where settings live, in budget, journaled or not	instructions_budget, a_typical_company_gets_the_whole_connect_text
Fuzzed journals of the new events open in the writer and the viewer alike, verify, and read every way without a panic	fuzz_settings_replay (and fuzz_store_replay with the new types)
A record changes no figure	Lean Step.record_changes_no_figure, Reachable.records

P1 mutation testing (2026-10-17)

Every mutant in the P1 diff (--in-diff), per crate, against that crate's tests and its nearest callers' (the recipes' settings: STORE_CASES=64, MCP_CASES=16, no shrinking). First run, then after targeted tests:

Crate	Mutants	First run: caught / timeouts / unviable / missed	Missed after
ledger-core (with ledger-store's tests)	486	318 / 5 / 41 / 122	1 (equivalent)
ledger-config (with ledger-cli's)	72	44 / 0 / 2 / 26	0
ledger-store	113	81 / 0 / 28 / 4	1 (equivalent)
ledger-mcp	260	156 / 0 / 96 / 8	0
ledger-gui	25	7 / 12 / 3 / 3	0

No survivor was a bug; each was a test gap, now closed by a test of the law it broke:

• Core. tests/settings_units.rs: every settings accessor's exact value, the company profile and its order, every party-policy spelling, fiscal-year bounds off January, the TIN detector's joiner limits, each text, share and month-day boundary, every tax classification and the return it names, the one-quadrillion cap, today in the company's time zone, and the display of members, lists and the masked EIN. tests/conventions_units.rs: slot names (32 and 33 characters), summaries cut at 160 characters, template bounds (2 and 50 lines kept, 1 and 51 refused, a share out of (0, 1] named by its line), the approval fingerprint against an independent FNV-1a of the hashed text, approval rules at the limit and one cent over (debits only), and which fields make a convention's revision.
• Store. An empty import still moves the books in (once); a posting template replay can't read is newer.
• Config. The TOML comment scanner (a # in basic and literal strings, an escaped quote), comments carried by an import, a masked EIN matching, not matching and into empty books, an empty list changing nothing, differences naming each field, the export's provenance lines, effective_receipt_policy with and without config.json (tests/effective_policy.rs).
• MCP. Live::journaled reads no file, sync reloads once per change; the books://start, settings and conventions resources; a renumber names exactly the conventions that name the old code.
• Viewer. The Company page's cards (tests/kept.rs): live conventions and not retired ones, standing decisions and not superseded ones, open items and not resolved ones, who decided each and when, a late item saying so in words ("overdue since", added for this: colour alone told only the sighted), and the empty-profile copy of books that keep their settings. --vault-key-file wins over the settings and an unknown argument exits 2 (tests/vault_key_flag.rs). The first run's 12 timeouts were builds slowed by parallel work: the rerun caught them all.

Equivalent: holds_printed_tin mapping a full-width digit by / instead of - (every such digit becomes the digit 1: it asks only whether a character is a digit), and approval_gate's fast path (|| made &&: with rules off or none, the probe's approvals_missing is empty either way, so only the cost differs).

After the cutover (2026-10-17). Two fixes found by the first company's P1 cutover, mutation-tested on their diff (27 mutants: 22 caught, 4 unviable, 1 equivalent): the K-1 worksheet prints a share by its value, at least two places ("50%" and "0.5" alike print "0.50": a_share_prints_the_same_however_it_was_written, and spec_vault's package test), and the filing scan passes the company's own EIN printed 2-7 and nothing else (the_company_s_own_ein_printed_as_an_ein_passes, tests/tin_files.rs the_company_s_own_ein_goes_in_and_no_other). Equivalent: share_text's scale() < 2 made <= 2 (padding a two-place share to two places changes nothing).

P2 slice 1: one executable (2026-10-18)

wanderbooks dev-stdio and wanderbooks gui run the server and the viewer from the one executable (plan D-22); tests/one_executable.rs drives both, and just server-only builds, clippies and tests the build without the viewer and fails if it links a window library. Mutation on the diff, two jobs, the viewer left out (owner, 2026-10-18): the server's run against the server's tests, 14 mutants, 12 caught or unviable, the exit text's then caught by a new test, and one equivalent (< vs <= on the ten-second lock deadline); the CLI, 24 mutants against its tests in the default build and the run_gui arms again in the server-only build (--no-default-features), every one caught in the build where its code exists.

P2 slice 2: the data root (2026-10-18)

ledger_store::root (plan 3.4, 5.5) and wanderbooks setup: tests/root.rs (32), the module's unit tests (4), ledger-cli/tests/setup.rs (3). Three review rounds (12 findings, then 5, then 1, all fixed). Mutation on the diff, the viewer left out, two jobs: the CLI, 7 of 7 caught; root.rs, 47 missed on the first run, then new tests (the blob copier's strays, errors other than not-found, the buffer that grows behind getpwuid_r/getgrgid_r, the private-group rule) and a rerun: 201 mutants, 163 caught, 23 unviable, 1 timeout (the growing buffer halved instead of doubled, which never ends), and 14 left, none reachable by a test:

• the lookups' failure guards (rc != 0 || null || null with &&, five): on every lookup that succeeds they agree, and this account's own lookup always succeeds;
• NotFound guards whose other errors end the same way (setup's symlink_metadata of the chosen root, where creating fails with the same error; the location note's removal, unreachable after the note was checked to be a plain file; a subfolder's lookup inside a root already opened);
• create_book's clean-up after Store::create fails in a folder it just made (no test can make that fail);
• make_private_dirs' AlreadyExists guard (two setups racing);
• sync_dir (durability, not visible to a test);
• the group's member check (! deleted), which agrees on every account whose own group lists no members, the usual case.

Viewer color schemes (2026-10-19)

ledger-gui/src/schemes.rs (docs/color-schemes.md). No mutation run (the viewer's rule); its two musts are tested directly instead:

• schemes::painted::every_scheme_paints_the_same_words_and_figures_readably draws thirteen pages (an entry, the company, assets, documents, overview, cash, profit, transactions, the P&L, the balance sheet, accounts, parties, the journal) in all 80 schemes, a thread a page, and reads what was painted where it can be seen: every run of text, report rows included, is the same and in the same place in every scheme, and each is at 4.5:1 or better against what was painted under it by then (the fills in paint order, cut to their clips, translucent ones laid over what was below; every section of a text, its own color or the fallback). It found egui's placeholder text (its weak text, 60% alpha of the text) at 2.8:1. Not painted by it: hover, selection and new-entry rows, tooltips and the menu, whose grounds the palette tests check by arithmetic.
• the_system_turning_light_or_dark_changes_nothing: starting as eframe does (following the system), a scheme chosen and the system then flipped leaves every painted color as it was. It fails on the first version, which set only the current theme's style.
• The palette tests check every scheme: every text color at 4.5:1 on every ground (soft fills included), text over secondary over faint each at least 1.2 times the contrast of the next on its worst ground, chart series at 3:1 on cards and the hover tint, the charts' three series shown together and gains, losses and text each ΔE 20 or more apart, the logo's initial readable on the accent, light or dark as its background is, and the filter showing exactly its mode; the menu test chooses, filters and keeps a scheme, and its accessible labels check only the family in force and select the variant in force; app::tests restores the scheme (and the old light/dark choice) from the preferences.

The first version's review (2026-10-19) found figures turning unreadable when the system's theme flipped, Ayu and the families after it out of reach in a short window, Income and Net the same color in twelve schemes, pills, faint figures and the logo initial below 4.5:1, a new-entry tint that bleached reds and greens, and a "same figures" test that compared only accessibility labels (no report rows); all fixed, with the tests above. Round 2 found secondary and faint text made alike by lifting each alone (identical in Wanderbooks Light), the painted test picking a text's ground without paint order or clips, and every family's accessible label carrying the hidden check; fixed, with the tests above. The owner, trying it (2026-10-19): Ayu out of reach (the family list scrolled inside the menu, its scroll bar hidden), the families not alphabetical, and a click on a variant's colors doing nothing. Now the families are alphabetical, in columns with no scrolling, and a variant's whole row is its button; every_family_is_on_screen_in_order_and_a_whole_row_chooses checks all three in a tall window and a short one. The live preview (owner, the same day) is checked by a_hovered_scheme_is_shown_live_and_only_a_click_keeps_it with frames 10 ms apart: not worn before 50 ms, worn after, the next row's scheme on moving, the one in force off the rows and at once on closing, nothing kept until a click. Earlier: the viewer's own light palette's green below 4.5:1 on the sidebar (4.35:1), and a first fix (moving colors toward the text color) that turned Everforest's red and green into the same grey; colors keep their hue and change only lightness.

P2 slices 3 to 8 (2026-10-19 to 2026-10-20)

From slice 3 on, mutation testing waits for P12 (D-33, owner 2026-10-20: "put a pause on all the mutation testing … For now I want to focus on the building"). Each slice was reviewed until a round came back clean and passes just check; what P12 must still cover is listed at the end.

Slice 3, opening and closing the books. The books server on local sockets (ledger-mcp local.rs, admin.rs, opening.rs), the host, its leases and the agents' bridge (ledger-host). ledger-cli/tests/ local_server.rs (the server and its admin socket), open_while_held.rs (the plan's named P2 tests under names of their own: last-holder close, one host and server, the bridge opening closed books, cold start, restart with writes across it, close during bursts of posts, SIGTERM and SIGHUP, a clean host from a hostile bridge, respawn and backoff, no TCP, the app scope, cancel, malformed input, a frozen host and server, books made mid-session), setup.rs, one_executable.rs; unit tests in ledger-host, admin.rs, local.rs, opening.rs; ledger-store/tests/root.rs (adoption). Eight review rounds (13, 22, 9, 4, 4, 10, 3, 3 findings; the last three found the core clean). The burst tests compare the posts in the books with the posts answered.

Slice 4, access. Tokens, the door, scopes, the access log and the owner passphrase (ledger-store auth.rs, access.rs, chain.rs, passphrase.rs; ledger-mcp scopes.rs, access.rs): their unit tests, local_server.rs (401/403, a session bound to its token, every call recorded once with refusals, a damaged token log refusing every agent), open_while_held.rs (the bridge picking up a token made mid-session), setup.rs (the passphrase prompts, at a real terminal).

One keyring item per token (2026-10-22). On the live books a reconnected bridge got no token from a keyring that couldn't be read, was told to "make a token", and after token create --replace ran on a token the keyring no longer gave while download read a revoked one. The test keyring is now a folder per collection that a test can lock, make unreachable, or plant a second item in (tokens.rs INVARIANT 4), and the keeping and reading logic is shared with the OS keyring's. tokens.rs unit tests (two items are said, never one of them given; keeping removes every item first and reads back; a keyring that keeps something else is refused; locked or unreachable is an error, never no token), bridge.rs a_keyring_that_cant_be_read_is_said_never_make_a_token and each_new_session_reads_the_keyring_again (against the scripted server), local.rs a_token_check_says_whether_the_text_is_the_live_one, admin.rs (token_check carries a hash, never a text), and open_while_held.rs token_check_one_item_per_token_and_a_keyring_that_cant_be_read (token check's every state end to end, a planted second item refused by check and by the bridge and repaired by --replace, a bridge with an unreachable keyring told so, a token the keyring can't keep revoked again). The real Secret Service stays behind the ignored os_keyring_keeps_and_forgets: tests never touch this computer's keyring.

Slice 5, files in and out. Uploads by hash and size, exports handed over by the server (ledger-store uploads.rs, exports.rs; ledger-mcp tools/files.rs; wanderbooks upload/download): unit tests (expiry, the grant replaced or lapsed while bytes arrive, a second send refused), local_server.rs, one_executable.rs, tin_files.rs and the MCP specs the import roots' removal changed. Four review rounds.

Slice 6, the viewer. Finding the books in the data root, settings from the journal, presence through ops/, Save a copy and Open, the Export menu, one builder for the CPA package (ledger-package): the viewer's suites (exports.rs, read_only.rs, show.rs, kept.rs, live.rs and the rest), ledger-package/tests/package.rs, ledger-store saving.rs and ops.rs.

Slice 7, backups and restore. ledger_store::backup, Root::restore, ledger-mcp backup.rs and tools/backup.rs, the loop in local.rs: ledger-cli/tests/backups.rs (17: both targets after a write, the quiet before a backup, close and catching up at the next open, admin only and the head unmoved, a target that moved on, a failing target waiting while the others carry on, a damaged record, restore beside and on a clean install, of the previewed backup only, with its vault and key, refusing damage, never overwriting, a failed replace, a restored copy leaving its original's repository alone, a backup folder never made again, drills on open and a failed drill flagged), open_while_held.rs (books restore and its default id), backup.rs's unit tests (20, among them links and strangers refused before checkout, target and archive hooks never run, the owner's hostile git configuration never spoiling a backup, repositories with settings of their own or something beside them refused, fake gits for the time limit and the process group), tests/root.rs (never moving books something holds). Five review rounds (about 25, 15, 10, 7 and 3 findings, all fixed) and a sixth that only attacked the repository guard (one low finding, fixed). The backup suite passed every run three at a time.

Slice 8, the viewer's menu, setup, no confinement (D-32). ledger-gui/tests/owner_menu.rs (each item through a fake owner, the restore checked first, nothing of the books written, busy states; screenshots looked at), open_while_held.rs (books back-up, the viewer holding new books and closing the books, connect making anew a token the keyring lost and saying when an agent refuses, the two lease intents), one_executable.rs (the scaffold gone, and saying so), spec_kept.rs (isolation is same_user (advisory)). Two review rounds.

Slice 9, the cutover's put-aside. wanderbooks books put-aside ID DATA-DIR [--vault DIR --vault-key FILE] [PATH...] (root INVARIANT 8) moves the old copies of adopted books whole into numbered folders of their own in legacy/, a list of where each came from written first. ledger-store/tests/root.rs (seven: a preview moves nothing; every byte moved and the list written; refused while the books lack its journal, a stored file, a vault record or the key, or when its head moved since the preview; refused while held open, for a link, a path named twice, inside the root or missing, and for a vault or key given as a plain path; what adoption left behind and records the books sealed anew go aside too; a registry rewritten is refused; a move cut short puts back what it moved), ledger-cli/tests/open_while_held.rs (from the command line). Three review rounds of data safety alone (12 findings, then 5, then 3 minor; all fixed but one: a vault record the old journal never named, a crash between sealing and journaling, would be listed as the books' newer copy; nothing is lost, the old vault going aside whole; hardening for P7).

Tests that mutation found, before the pause. Pass 1 on slices 3 to 6 (each crate's own tests, the viewer left out): ledger-store 385 mutants (44 missed), ledger-package 137 (38), ledger-mcp 497 (247), ledger-host 666 (275), ledger-cli 47 (11). Pass 2 (the survivors again with the end-to-end tests) left 38, 13, 90 and 11 in the first four; the ledger-host pass was stopped. Then:

• ledger-cli's 11 are all in the #[cfg(not(unix))] stubs (owner_passphrase, run_files, run_local, run_server): not compiled on Linux, so equivalent here;
• ledger-mcp (access.rs, admin.rs, settings.rs, tools/files.rs, tools/kept.rs): all 14 killed (each access record's request id, the admin socket's four-MiB line, TokenText's and CallError's text, no server meaning nothing sent, a book's own settings before it holds any, the caller's token in a printed command, a long name cut to 255 bytes, a settings file moving into the books). One real bug: the command line took an admin answer longer than four MiB, or cut off before its newline, whenever the bytes that came still parsed; it is refused now (an_answer_is_one_line_of_at_most_four_mib);
• ledger-package: tests for a dotfile's twin, receipts on the year's first and last days, a vendor's payments from the settings' accounts alone, the index's amount as written (package.rs:482's debit side is not equivalent: amounts keep the scale they were written with), the TIN source's three cases. Two real bugs, found reading the naming: a twin's number went on the last dot of the whole path, so in a folder with a dot ("a.b") the second "notes" landed in another folder; and a name of dots alone ("..") could climb out of its folder when the zip is unpacked. Both fixed (a_twins_number_goes_on_its_own_name_and_no_name_climbs_out_of_its_folder);
• ledger-store: a private log stays 0700 (chain.rs:204's two mutants are not equivalent); the two flock flag mutants in ops.rs (| for ^ on disjoint bits) are equivalent. The other 34 were triaged, not yet tested (masking keys one by one, a null TIN, token replacement across books, the chain's messages, export and upload expiry boundaries, the short-salt record, the dotfile and no-hard-link paths of save_new).

For P12: the whole diff from 168494b (main before slice 3) to the tip; ledger-store's 34 triaged survivors; ledger-mcp's local.rs (45) and server.rs (31) survivors; ledger-host's pass 2; slices 7 and 8 from scratch (ledger-store backup.rs and root.rs, ledger-core settings.rs, ledger-mcp backup.rs, tools/backup.rs, local.rs, admin.rs, ledger-host commands.rs, ledger-cli). The survivor lists are kept with the run's output, outside the repository.

P3: odd cents (2026-10-20)

Defect 17 (rules.md B-13; D-10, D-38), built without its mutation run (D-33); what P12 must cover is listed at the end. Every expected figure is worked by hand in the test's comment.

The named regression. the_audit_odd_cent_never_piles_up_across_closes (ledger-core tests/odd_cent.rs): an audit finding's −287.53 at 50/50, anonymized, with a close to retained earnings between two members closes. The run rule left A −287.54 / B −287.52; the rule since P3 gives −287.53 each (March: Dr 3000 143.76, Dr 3001 143.77). Its bookspec example is bookspec/examples/members-close.odd-cent-across-closes.toml; it and the other members-close.* examples are checked with every example by ledger-core tests/bookspec.rs (every_bookspec_example_holds).

Core (ledger-core tests/odd_cent.rs): a true-up from inception (members_closes_true_up_from_inception); a close that posts nothing (a_close_that_posts_nothing_carries_no_true_up) and one that posts only a sweep (a_true_up_rides_on_a_distribution_sweep, P3 review R-3); a reorder (reordering_members_keeps_counting_from_the_first_close); a share change and a return to the old shares (a_share_change_starts_a_new_count); a member joining mid-year (a_member_joining_mid_year_starts_a_new_count, R-8); a journaled start other than the derived one (a_journaled_start_other_than_the_derived_one_is_refused); whole yen and thousandths of a dinar (a_yen_book_closes_to_members_in_whole_yen, a_dinar_book_closes_to_members_in_thousandths); the statement on a date before and after its period closes (a_members_capital_on_a_date_does_not_change_when_its_period_closes); a pending true-up that shows only once posted (a_pending_true_up_shows_only_once_posted, R-1); three members at 33.33% / 33.33% / 33.34% over twelve months, the statement checked against the same entries never closed on every day of the year and the K-1 worksheet at every month end (three_members_at_a_third_each_over_twelve_months). Added by the P3 review: a gold book splits to the finest unit a line carries, not cents (a_gold_book_splits_to_the_finest_unit_a_line_carries); the K-1 worksheet shares contributed property in whole yen (a_yen_books_k1_shares_property_in_whole_yen, and share_property's unit test in k1.rs); a reorder of the members in the settings moves no cent on a day before the count's first close, nor in "other" (a_reorder_moves_no_cent_before_the_counts_first_close). Each fails on the code before the review's fix. Properties (512 cases each): members_capital_never_drifts_a_cent_from_their_share (a legacy prefix under the three earlier rules, then months closed to the members in either order, to retained earnings or not at all; a close that posts nothing changes no capital, R-3), each_members_capital_chains_and_holds_through_closes, period_ends_rise_with_close_order (R-10.6). In statements.rs: a_different_close_ends_a_legacy_run (the run rule, still replayed) and a_different_close_no_longer_restarts_the_count, the run rule's arm of a_run_of_closes_never_piles_up_rounding, and February in a_partnership_closes_into_members_capital (Bob 683.33 → 683.34: his share of February's unclosed income is what its close will give, D-38). Unit tests in kernel.rs (apportion_cumulative_refuses_mismatched_or_out_of_range_inputs, apportion_cumulative_trues_up_a_legacy_split) and periods.rs (allocate_cumulative_*: whole yen, a dinar, a loss, a 28-place share refused, R-5). Bridges (tests/kernel_bridge.rs): apportion_cumulative_agrees, allocate_cumulative_agrees_with_the_integer_model.

Store (ledger-store): members_closes_replay_under_the_rule_they_were_journaled_with (each rule; with a close to retained earnings between, the rule since P3 ends 0.01 / 0.01 and the run rule 0.02 / 0.00); tests/member_closes.rs: the_first_cumulative_close_declares_its_feature, an_unknown_rounding_is_newer_not_corrupt (R-9), a_count_that_starts_later_journals_its_start (a share change: since_seq 2 journaled and replayed; added by the P3 review), a_close_journaled_with_another_start_refuses_to_open, the_first_close_after_the_upgrade_trues_up_the_old_rules, on the new old-books fixture x_member_closes (written by main 00226a4c's Store API: three untagged closes, three "largest_remainder", "cumulative" broken by a close to retained earnings; it opens to main's figures in books_an_earlier_version_wrote_open_to_its_figures, R-2); format.rs an_older_reader_stops_at_the_members_cumulative_feature.

MCP and viewer: ledger-mcp close_period_shows_each_members_running_split (tests/mcp_stdio.rs: the preview's members is the confirmed one; after a restart, list_periods' close_rule and the statement of members' equity); old_books_name_each_closes_rule_and_true_up_at_the_next_close (the old-books fixture x_member_closes through the server: every close_rule an earlier rule gives, and December's true-up, the preview the confirmed close); ledger-gui a_members_page_shows_the_same_capital_before_and_after_a_close and a_yen_members_page_splits_in_whole_yen (what is owed to each member and their property, in whole yen) (tests/odd_cent.rs).

Proofs: docs/verification.md (the three P3 laws).

For P12 (nothing run here, D-33): kernel::apportion_cumulative (the length and range guards; checked_sub for checked_add; the subtraction skipped); periods::allocate_cumulative (the sign; given not negated for a loss; places ignored; the exactness filter, zero products included); Ledger::members_regime and regime_where (skip versus break at a close to anything else; the order-free compare made ordered; the date filter <= for <; given added to the wrong member; the count's order; the next count's order as of a day before it begins); Regime::allocate (the order); Ledger::members_split and close_period_to_steps (the start check; the posts gate; the recorded rule; the sweeps before the parts); member_close_run (it reads only run-rule records); member_close_split; reports::members_equity (allocate(C) replaced by given, R-1; places; "other"'s order); k1::share_property and the viewer's owed_to_member (places); the store's close_to_from_journal and close_period_to (the tag mapping; since_seq's parse; a tag that isn't text; the feature declaration); format::declared_knowing; the MCP's close_period and list_periods fields; Currency::allocation_places. P3's accept counts ledger-core and ledger-import (R-6); the store and MCP mutants above are for the whole pass.

P3: the IIF and as-of (2026-10-20)

Defects 7 and 21 (plan P3; the owner's decisions D-36). Rules docs/spec/rules.md B-33 (a package as of a day) and B-34 (the IIF). No mutation run (D-33): what P12 must cover is at the end.

Named regression tests, each from its reproduction, on anonymized fixtures:

• Defect 7, DOCNUM: ledger-import tests/spec_import.rs iif_docnum_is_the_entry_id (a draft never posted, three entries posted out of id and date order: DOCNUM 3, 2, 4 on the TRNS and every SPL; the file had written 1, 2, 3).
• Defect 7, the characters (D-36, plain ASCII): iif_writes_plain_ascii_and_lists_every_change (accented letters, Chinese, emoji, a fullwidth colon and fullwidth digits, a tab in a name, controls, a decomposed accent, private use: each written form exact, every change listed exactly), iif_every_line_ends_cr_lf, iif_change_warnings_are_one_line_each, iif_keeps_a_tin_readable_to_the_package_scan (an en-dash or no-break-space TIN in a memo stays a TIN to the package's TIN scan), iif_distinct_accounts_never_share_a_name (review R2: duplicate names, by case, siblings, a fullwidth colon against a hyphen, two private-use names; a name that is another's tagged form tagged in turn; the clash left when two codes are written alike refused), iif_fits_quickbooks_desktop_limits (Intuit's limits, found in the P3 review: a level past 31 characters cut, two alike once cut tagged, a subaccount under its cut parent; an account number past 7 characters and two written alike left out of ACCNUM; a memo past 4,095 cut; every line of the warnings exact; a hand-built level past 31 refused), iif_warnings_group_the_memos_by_what_is_written_differently (the lead's call: 100 depreciation memos with an em dash make one line), iif_warnings_never_hold_a_tin (a TIN in a memo or an account name, in ASCII or fullwidth digits, never in a warning), iif_field_transliteration_exact and iif_paths_and_transliteration (the old expectations, "Caf? meals" among them, rewritten to the rule).
• Defect 21, the package's IIF: ledger-package tests/package.rs as_of_package_iif_stops_at_as_of (next year's rent was in the file; now the four entries of the year, by id, tied to the trial balance), the_iif_through_as_of_at_its_edges (an entry on as_of in, the day after out, a reversal after as_of leaving its original, as of a day before the first entry: the accounts and no transaction).
• Defect 21, every file: every_file_in_an_as_of_package_stops_at_as_of (review R4: books the same through as_of, one set with a 1099 payment, its receipt and an asset bought the day after, a reversal of the entry dated as_of, the members' contributions and an earlier desk sold, build the same package byte for byte, every file and which files there are, PDFs included, with and without TINs and receipts, with and without a fixed asset register, mid-year and at year end; a package days later sees the activity). Undoing any one of the as-of bounds (the IIF's entries, its FIXASSET typing, the 1099 worksheet's through, the fixed asset register's presence) fails it; checked by hand.
• D-36, the 1099 worksheet: the_1099_worksheet_stops_at_as_of (a payment on as_of counts, the day after doesn't; a vendor under the threshold so far is not yet reportable; a year-end package and the tools' worksheet unchanged).
• D-36, closes: iif_leaves_out_period_closes (two months closed: no close written, income and expenses equal the year's profit and loss, balances the trial balance without the closes).
• Plan P3's accept, a bookspec example per regression test: the as-of ones (bookspec/examples/as-of-package-stops-at-as-of.toml, 1099-worksheet-through-as-of.toml) and the IIF's (iif-quickbooks-journal-file.toml, formats appendix), each expected value derived by hand. ledger-core tests/bookspec.rs loads every example, the formats appendix's too, and checks the as-of ones' trial balances, profits and losses and 1099 payments against the engine (every_bookspec_example_holds, the one loader of every example; the tests beside it refuse a query no crate answers, a format query outside the formats appendix, an unknown appendix, a payee not in the setup, a figure query leaving out an account, payee or entry line it covers, an as-of query given a period, after past the last event, members' shares not summing to 1 and a members close declared with another rounding, and show after asks the books after that event); the_bookspec_iif_example_matches_the_engine reads the IIF example and checks the engine gives exactly its file and changes.
• Review R18 and the README: one_list_of_cash_accounts_per_package, the_readme_lists_what_the_iif_writes_differently (the memos grouped: six depreciation memos and a lunch with an em dash, one line).

Exhaustive and property tests. iif.rs's unit tests write every one of the 1,112,064 Unicode scalar values (alone, after a letter, before one) and check the field is printable ASCII without a double quote and a fixed point, its changed runs empty exactly when it is unchanged, and a level never empty, colon-free, trimmed and at most 31 characters (a complete check over the finite alphabet; review R15); with_tag's and changed_runs' edges by hand; the_transliteration_table_is_pinned samples deunicode 1.6.0, pinned exactly in Cargo.toml (R14). Properties: iif_round_trips_random_books (memos mixing ASCII, Latin-1, dashes and quotes, every kind of line break, controls, CJK, emoji, combining marks, private use; DOCNUM, CR LF, the changes list exact), iif_names_never_clash_and_every_change_is_listed (random charts from a pool of clashing names, long names alike once cut, codes with colons, past 7 characters, and one alike another once trimmed; every warning line checked against the books and the file), iif_ties_to_the_trial_balance_as_of (2,000 cases: random books with reversals and closed months, random as_of; the file's entries and balances against the trial balance without the closes).

End to end. ledger-mcp oracle_mcp.rs: iif_declares_accounts_by_role_and_balances_every_transaction (as_of, DOCNUM the ids, the warnings exact: the fixture's line-broken memo and the engine's own "Depreciation — Laptop — 2025-03" memos, the alias, a range refused), iif_without_as_of_is_as_of_today_and_ties_to_the_trial_balance (review R5), cpa_package_holds_the_year_and_its_evidence (the IIF from the prior year's sale through as_of; a payment after as_of to the contractor left out of the 1099 worksheet; the note's count); mcp_stdio.rs (a Chinese account name over stdio: ASCII text, CR LF, warnings); spec_mcp.rs (iif with as_of); ledger-gui tests/exports.rs (the README's IIF line names the as_of).

Names in every script, in the PDFs and the viewer. Inter has no Chinese, Japanese, Korean, Arabic, Hebrew, Thai or Devanagari glyphs: every such character printed as Inter's empty box (glyph 0), and the viewer drew boxes too. ledger-import src/fonts.rs now bundles the fallbacks, each once: a subset of Noto Sans CJK SC (fonts/NotoSansCJK-LICENSE.txt says how it was made) and Noto Sans Arabic UI, Hebrew, Thai and Devanagari, unmodified (fonts/NotoSans-LICENSE.txt: versions, upstream commits, SHA-256; 412,968 bytes for the four). Arabic is the UI form because Noto Sans Arabic 2.013 draws a letter's dots as marks of their own, which Typst writes as text runs of their own: its PDFs' text read "شلام" for "سلام", with letters doubled. No emoji font (about 10 MB): an emoji prints as an empty box in the PDFs. Tests: fonts.rs every_template_names_every_fallback_in_order; pdf.rs chinese_japanese_and_korean_print_as_written and arabic_hebrew_thai_and_devanagari_print_as_written (every glyph from its script's font, none glyph 0); spec_import.rs pdf_keeps_chinese_japanese_and_korean_names (the ToUnicode map) and pdf_prints_every_bundled_script_as_written (the PDF read back with hayro, the viewer's own reader: Arabic and Hebrew read right to left give the words, the lam-alef ligature included; Thai, Devanagari and Chinese left to right; every font embedded; failed with Noto Sans Arabic 2.013). The viewer registers the same FALLBACKS after its own fonts in every family (ledger-gui theme.rs every_family_falls_back_to_the_noto_fonts: the very bytes, by pointer, and a real glyph for each script's letters in every family) and tests/scripts.rs account_names_in_other_scripts_show_as_written (the Accounts page paints each name; with SHOT_DIR set, it saves scripts.png: looked at, 2026-10-20). egui shapes and joins each word, right to left for Arabic and Hebrew, but doesn't reorder the words of a right-to-left phrase: "مكتب الرياض" shows its two words left to right.

TINs in any script (B-26). ledger_core::parties::has_full_tin missed "１２３－４５－６７８９": the fullwidth hyphen-minus, the ideographic and thin spaces, the Hebrew maqaf and the other Unicode dashes weren't separators, and a zero-width space or a right-to-left mark between digits ended a run. Past ASCII every Zs space, every Dash character and the compatibility forms of the dot, slash and underscore now separate, and default-ignorable characters don't count (docs/spec/sources/unicode-tin-text.md, Unicode 17.0); ASCII reads as before. spec_parties.rs has_full_tin_reads_every_script_and_separator and the property has_full_tin_keeps_its_ascii_reading (2,000 cases: on ASCII the same answer as the old reading, kept in the test; elsewhere it finds at least what the old one did).

Second review (2026-10-20). QuickBooks gives a subaccount its parent's type (Intuit): iif_a_subaccount_of_another_type_stands_at_the_top_level (a bank account under a header that is no bank, an asset's cost under "Fixed assets": each written at the top level, keeping its type, listed, its own subaccount with it, a name it then shares told apart by code); check_iif now checks every subaccount's type is its parent's and every parent is declared before it; iif_declares_each_parent_before_its_subaccounts. The file names no customer or vendor (Intuit states no need for an IIF journal; QuickBooks Desktop asks for one on A/R or A/P): the_readme_names_the_entries_on_receivables_and_payables. A memo line whose digits are masked says so (iif_warnings_never_hold_a_tin, which now also holds a name and a memo that are a TIN only once written, digits a tab apart: with has_full_tin reading every script, nothing else tested the masks' second pass). iif_fits_quickbooks_desktop_limits now holds a number of exactly 7 characters (kept) and two alike but for case (left out): undoing either bound of the 7 had failed no test. Each was checked by undoing it and seeing its test fail.

The GnuCash differential (oracle/) compares the engine's figures and has no IIF and no package, so it has nothing to re-adjudicate here.

Each of the review's fixes was checked by undoing it by hand and seeing its test fail (2026-10-20): the 31-character cut, the clash loop's second round, the double quote, the TIN mask, the memo cut, each reason a number is left out, the memo grouping, the tag's colon; and, for the builder's, the as_of <=, the register's presence, the 1099 through, the closes filter, the FIXASSET date filter and the package's cash list.

For P12: mutation over ledger-import iif.rs (each breaks arm, the control, quote and None arms of each_piece, the deunicode post-mapping, segment's colon, trim, cut and "?" fallback, tag, with_tag's room, the clash loop's depth bound, rounds and tag, journal_to_iif's clash and length refusals, the number rules, the memo cut, each changes comparison and its order, warnings' grouping, order and masks, shown, DOCNUM, EOL), pdf.rs (the fallback font), ledger-package iif.rs (<= in the as_of filter, the closes filter, the FIXASSET date filter) and package.rs (the cash and financing resolution, the register's presence, the 1099 through, the README's IIF line, closes sentence, warnings block and 1099 wording), and ledger-core form1099.rs (the through bound), ledger-mcp server.rs (the iif report, range and as_of checks, warnings, the package note), ledger-gui menu.rs (the note). From the second review: iif.rs iif_accounts' type filter on parents and apart_from, parents_first, the AtTopLevel change, the TIN note's condition and receivable_payable; fonts.rs and theme.rs font_definitions; the README's A/R and A/P sentence; ledger-core parties.rs tin_separator's arms and tin_invisible, and the gap that doesn't count them.

P3: cash flow (defect 1, 2026-10-20)

The statement of cash flows was rebuilt by the direct method (rules.md B-14, D-35), and what a member or a lender pays for the company shown as cash borrowed and spent (D-42, rule 11). Built, reviewed twice, just check and just prove; no mutation run (D-33): what P12 must cover is at the end.

• Named regressions (crates/ledger-core/tests/spec_cash_flow.rs; also bookspec examples, bookspec/examples/cash-flow.*.toml, checked by tests/bookspec.rs on every run): defect1_reversed_contributions_foot_regression (the minimal reproduction: a property contribution reversed, which broke footing by the contribution's amount), defect1_two_member_llc_first_year_regression and defect1_two_member_llc_as_of_march_18_regression (a replica of the 23 entries defect 1 was found in: the same shape, order, accounts and roles, Member A and B and generic vendors, every amount and date made up, so none is the real books'; to 2026-03-31, operating -596.24, investing 0.00, financing +2,216.40, the change in cash +1,620.16, and to 2026-03-18, operating -549.86, financing +2,549.86, worked by hand in the test's doc comment).
• The rule, case by case (same file; each oracle worked by hand from its paragraph in the test's doc comment): disposals at a gain, a loss and before any depreciation (disposal_proceeds_all_investing); a sale on an IOU (disclosed, flagged, with the fix); property contributed; what a member or lender pays or receives for the company (D-42, rule 11): an expense through Due to Members, equipment a bank paid for, an expense paid into capital, a financing card, part cash and part a member's, a refund to a member, a customer paying a member, a payment made for the company and its reversal (in the period and alone, a prepaid and equipment too), the reimbursement, the uses' order (rule 11's convention); and what stays noncash: property a member owned (with members configured and without), the seller's credit (flagged), interest and guaranteed payments charged to a creditor, a fee withheld on a contra-liability. From the second review: odd shapes (two cash accounts in one entry, one account on both sides, a reversal chain across the period start, a close: odd_shapes_foot_and_net) and taxes and government fees as other payments, (g); reversals in the period, alone, taking their root's sections and class, and reversals of reversals (review item 1); part cash (50-5); a fee withheld from a loan; interest with principal, paid and received; one entry per operating class (a)-(g); depreciation; cash spent on a depreciation expense account (D1-e); the reconciliation tying to operating; closes; the start date; transfers between cash accounts; debt converted to capital, a note received for equipment, a trade-in (review item 2); the bill split (D-35, through a bill restored as a later version would journal it), and a bill payment reversed in the period; a card purchase of equipment, on an operating and a financing card; each member's kinds; the five role refusals and foot directly. From the P3 review: interest classed apart from the rest of an entry's operating cash (operating_cash_is_classed_kind_by_kind) and kept operating in a disposal; a loss on disposal on a revenue-typed or an expense-typed account; an investment sold at a gain; a reversal three levels down; and both of rule 3's conventions pinned (the sections' order, the kinds' order).
• Properties, 5,000 cases each (CF_CASES, default 5,000, about 16 s): prop_cash_flow_laws over random books of 33 templates (every shape the rule names, rule 11's included) and reversals of any earlier entry, reversals included: the sections are the change in cash and the model's; each section is its lines and kinds; the reconciliation is operating; an entry's lines are its cash, what was handled for it netting to zero, each line's cash part with the entry's sign; every disclosure is its parts' positive sum or its exchange; an entry and its reversal in the period change nothing; periods split and add; closing every month changes nothing; scaling scales every figure. prop_pure_entries_sections_are_movements: for pure entries, each section is minus its accounts' movement over the entries that touch cash or that a member or lender settled whole for the company (the plan's wording, with rule 11 modelled apart from the engine; review item 7's definition of pure). The older properties in spec_reports.rs are kept with new oracles (financing is the cash part of equity and designated debt plus what the loan or capital paid or received for the company, by an independent model of rules 3 and 11).
• Bridge: entry_flows_agree, apply_cash_and_exchanged_agree, constructive_agrees.
• Proofs: Kani entry_flows_sum_to_cash, entry_flows_pure_are_movements, entry_flows_are_bounded, no_cash_no_flow (entries of up to three lines), the reversal's mirror (entry_movements_of_a_reversal_mirror and flows_of_mirrors at three lines, entry_flows_of_a_reversal_mirror end to end at two, since the P3 surface review), take_is_odd_and_bounded, apply_cash_mirrors, apply_cash_spends_exactly, exchanged_is_bounded, constructive_nets_to_zero, constructive_mirrors; Lean cashflow_sections_sum_to_cash_change, entry_flows_sum, flows_reversal, constructive_nets, constructive_neg, constructive_sections_net, stmt_flows_sum, stmt_flows_reversal, operating_reconciliation_ties(_all), cashflow_reversal_nets, Reachable.cashflow_foots, Reachable.cashflow_is_change_in_cash (docs/verification.md, law 10).
• Sensitivity (P3 review, by hand, no mutation run): 18 deliberate breaks to cashflow.rs and kernel.rs (a dropped reversal flip, no netting, financing read as operating, no rule 4, no exchange disclosure, no interest class, no warnings, the bill's payments ignored, the label's depth parity, repeated codes allowed, depreciation disclosed, the sections' or kinds' order reversed, the customer party ignored, accumulated depreciation in the exchange, the interest exception dropped, rule 4 for investing accounts): 17 fail a test (4 of them only since the review's tests); one is equivalent today (mirrors ignoring amounts: every reversal mirrors its original until P4's drafts).
• Sensitivity, second round (after D-42, by hand, no mutation run): 17 breaks to rule 11 and the kernel's constructive (no lender pass, no member pass, no receipts for the company, a reversal not mirrored, a lender paying for no investing, capital paying for property, receipts for property, receivables not received, guaranteed payments or interest paid for, on_behalf not reported, the exchange on the net flow, owners' equity read as a lender, pairing that ignores on_behalf, the kernel's received sign, max for min, the uses' order reversed): 16 fail a test; one is equivalent today (pairing that ignores on_behalf: a mirrored reversal's real and constructive parts are each proved to mirror, Kani entry_movements_of_a_reversal_mirror, flows_of_mirrors, entry_flows_of_a_reversal_mirror and constructive_mirrors, so the check is defensive, for P4's drafts). The first round's 18 breaks, re-run on the reworked code (four adapted where the code moved), and one more for the taxes class: 18 fail a test, mirrors ignoring amounts still the one equivalent.
• End to end: the printed statement's footing, schedules and rows as the engine's (cash_flow_foots_and_reconciles, cash_flow_adjustments_appear_only_when_there_are_some, ledger-import); the CPA package's statement with both schedules (the_cash_flow_carries_both_schedules); the MCP tool and its exports field for field against the core (cash_flow_exports_equal_the_core_statement), the CSV's warnings, the settings' roles and a member-paid expense over stdio (cash_flow_reads_its_account_roles_from_the_books_settings), refusals naming the setting (cash_flow_refuses_contradictory_roles), the settings' problems from the same check; the viewer's statement as the server's, a loan the setting leaves out operating in both, a refusal shown as a reason and no number, and the page painted (the_cash_flow_page_is_the_servers_statement, a_refused_cash_flow_shows_why_and_no_number, the_cash_flow_page_paints_its_schedules; with SHOT_DIR, a PNG); the statement's warnings as Needs attention items (cash_flow_warnings_are_items); every old-books fixture's statement computed or refused, never an engine error (every_figure_over_old_books_is_computed_or_refused).

For P12 (D-33): cargo mutants on ledger-core's cashflow.rs (cash_flow, analyse, pairs, label, class_of, reconcile, warnings, bill_splits, role_problems, foot, on_behalf) and kernel.rs's take, apply_cash, entry_flows, constructive, exchanged; ledger-import's report::cash_flow; ledger-mcp's cash_flow_out, cash_flow_csv, export_cash_flow and settings_problems; zero unexplained survivors (plan P3 accept). Likely equivalent, to adjudicate: min against max in take where both bounds coincide, and the kind order's tie-breaks.

P3: rename, defaults and tax categories (2026-10-20)

Defects 15, 16 and 8 (plan/served.md P3; rules.md B-30, B-31, B-32). Every fixture is fictional (Fernhill Labs LLC, its members and vendors); no mutation run (D-33): the targets are listed for P12 below.

Named regressions, from the brief's reproductions:

• ledger-mcp tests/oracle_mcp.rs: show_refuses_start_after_end_defect_15 (1.1.1-1.1.2: refused, nothing reaches the viewer), show_refuses_a_derived_inverted_range_defect_15 (1.1.3: a start after today with no end, the message saying the end was defaulted), show_sends_the_dates_it_names_defect_16 (1.1.4: only an end covers its fiscal year to it; "as of" and "for" wording; the viewer gets the pair shown names), show_refuses_options_its_target_ignores_defect_15, and show_writes_the_viewer_command_for_each_target (resolved dates; a split never compared).
• ledger-mcp tests/mcp_stdio.rs: one_default_period_everywhere_defect_16 (a July fiscal year, a first entry the year before: P&L, by class, cash flow, the exported tax summary, members' equity, general ledger and journal (csv, json: the period's entries only) and the CPA package all give 2025-07-01 through 2026-03-31 for that end; with no dates every one gives today's fiscal year to date, the clock read before and after, R14), rename_account_end_to_end_defect_15 (the chart, a past period's P&L, the IIF's full names, verify, two journal lines, refusals write nothing, a restart keeps the name); mcp_period_statements_over_stdio's old pin (no start = the first entry) now pins the fiscal year (02-01) that holds the end.
• ledger-mcp tests/spec_tax_policy.rs: add_account_warns_without_tax_category_defect_8 (1.4.1), require_tax_category_refuses_defect_8 (refused without, created with, the import refused whole, clearing refused, a bill's 6999 created and named in its warnings and the digest), a_new_account_named_like_a_sibling_is_refused.
• ledger-gui tests/view_model.rs: needs_attention_flags_every_uncategorized_pl_account_defect_8 (1.4.2-1.4.3: unused and last-year-only accounts listed, headers and categorized ones not; Info under warn, Todo under refuse), and the_overview_numbers_are_the_books_numbers now pins that the viewer's default report range, its register's default and the server's resolver agree on random books and fiscal years.
• ledger-gui tests/show.rs: show_never_swaps_an_inverted_target_defect_15, show_report_with_only_end_uses_that_years_start_defect_16, show_all_dates_is_one_click_from_a_shown_register (review R4).
• ledger-store tests/store.rs: rename_account_changes_only_the_name_defect_15 (every figure, entry and earlier journal line, every projection row but accounts.name; refusals append nothing; reopen, rebuild and viewer), a_journaled_rename_replays_past_the_command_rules and a_journaled_clear_replays_under_refuse (B-28's pairs, review R5), the_tax_category_policy_refuses_only_what_it_says, books_written_under_p3_keep_their_names (fixture old-books/p3_rename, written once by write_p3_rename_fixture, --ignored; its figures are also in books_an_earlier_version_wrote_open_to_its_figures).
• ledger-store tests/format.rs: p3_features_wait_for_the_upgrade_and_are_declared_once, an_unknown_feature_before_a_rename_is_newer_at_the_declaration.

Properties: prop_period_defaults_resolve (ledger-core, 5,000 cases: every fiscal year start replay admits, every today and every mix of given and omitted dates, the calendar's edges weighted); prop_rename_changes_no_figure and prop_tax_policy_refuses_exactly (ledger-store, STORE_CASES, 64 by default); the refusal law (refused_commands_never_reach_the_journal) gains renames, accounts added with a category, and the policy turned on and off; the core model (tests/model.rs) gains Cmd::Rename, its model keeping a name per account.

Unit tests: calendar.rs (each PeriodDefaults invariant and scenario: fiscal years 01-01, 07-01, 12-01 and a lenient 07-15; the start day and the day before; year 1 under a July year, clamped; 9999-12-31; a one-day period; a start one day late; no month-day or chrono date panics); settings.rs (the_tax_category_policy_is_warn_or_refuse); ledger-config codec.rs (the_tax_category_policy_round_trips); ledger-core tests/spec_ledger.rs (rename_account_changes_only_the_name, rename_account_refusals_leave_the_books_unchanged, a_closed_period_or_a_role_never_blocks_a_rename, a_journaled_rename_replays_past_the_command_rules, a_new_account_named_like_a_sibling_or_holding_a_tin_is_refused, a_rename_reason_is_bounded_text_without_a_tin) and tests/tax.rs (needs_category's and the policy's truth tables, the catalog fitting every account a tool requires on every return, tax-exempt income at 0%); ledger-mcp server.rs period_tools_describe_the_one_default (every report tool's description ends with its kind's sentence and each date parameter is the shared constant; "all time", "beginning of time" and "first entry" are gone from every tool and schema; the resources say their period) and show_reads_each_reports_dates_as_the_viewer_does; handbook.rs (the period rule rendered from the same constant); hostile_args.rs hostile_renames_ranges_and_categories_are_answered.

Test fixtures that gave two accounts one name under one parent (ledger-core invariants.rs and spec_roles.rs, the store's refusal law) now name each for its code: the sibling rule is the commands', and existing charts and journals are untouched (replay takes any name). The viewer's spec_gui.rs small books give their one expense account a category, so "empty books have nothing" still holds now that an unused uncategorized expense account is listed.

Adversarial review (2026-10-21). Each finding has a test that failed before its fix (checked by breaking the code and watching it fail):

• ledger-core tests/tax.rs a_gain_on_business_property_is_figured_on_form_4797_on_every_return, ledger-import tests/spec_import.rs tax_summary_lists_form_4797_apart, ledger-mcp tests/spec_tax_policy.rs a_gain_on_business_property_is_exported_apart: a form_4797_gain_loss amount was ordinary income on every return (Schedule C included, whose instructions send it to Form 4797; on a partnership net section 1231 gain is Schedule K line 10), its Tax column the book gain; it is now TaxSummary::form_4797, book only, in no total.
• ledger-core tests/spec_ledger.rs a_new_name_is_one_trimmed_line_of_bounded_length, ledger-store tests/store.rs a_new_accounts_name_is_journaled_trimmed, hostile_args.rs (the 100,000-character name now refused): a new account's name was journaled untrimmed while a rename's was trimmed, and names had no bound and could hold a line break or tab.
• ledger-gui tests/view_model.rs all_dates_holds_an_entry_dated_after_today: "Show all dates" and "All time" ended today, leaving out entries dated after it.
• ledger-mcp tests/oracle_mcp.rs show_refuses_options_its_target_ignores_defect_15 (a split past 240 columns): books.show sent a split the viewer shows as one total.
• ledger-mcp tests/mcp_stdio.rs rename_says_what_the_new_name_moves_defect_15: the notes for the name-picked cash and card sets and conventions had no test of their own.
• ledger-store tests/store.rs rename_account_changes_only_the_name_defect_15 now reads the projection's renamed name itself (its comparison blanked that column); tests/format.rs lost a check that recomputed the gate's answer itself.

Landing on main (2026-10-21), beside odd cents, the IIF and the cash flow statement:

• ledger-mcp tests/mcp_stdio.rs the_default_period_never_shortens_the_iif_or_the_package: on a July fiscal year with entries before it, the general journal asked without dates is the fiscal year to date, while the IIF without dates holds every posted entry from the first through today under general_journal, journal and any capitals, refuses start and end, and the CPA package's IIF holds the entry before the package's fiscal year.
• ledger-core tests/bookspec.rs: the three examples are in the loader's one shape, and the loader gained what they need (bookspec README.md): setup.today and omitted dates resolved by B-30, header and tax_category on an account, a bill event, [[changes]] (a rename, the policy) made after an event's expectations, the queries period, day, calendar_year, account_names and uncategorized_accounts, and the commands rename_account, add_account and set_tax_category, tried on a copy and accepted or refused for a named reason. Each new key has a refusal test (a_period_other_than_the_rules_is_refused, a_refusal_for_another_reason_is_refused, an_omitted_date_without_today_is_refused, account_names_leaving_an_account_out_is_refused, a_change_is_made_after_its_events_expectations, a_command_runs_under_the_policy_in_force, a_command_with_values_is_refused).
• ledger-import tests/spec_import.rs: the IIF's tests (iif_names_never_clash_and_every_change_is_listed, iif_distinct_accounts_never_share_a_name, iif_writes_plain_ascii_and_lists_every_change, iif_warnings_never_hold_a_tin) make their siblings of one name, names with a tab and names holding a TIN by replay (replay_add_account), as books written before P3 hold them: B-31 refuses them in a new name, and the file must still keep them apart, write them on one line and mask them.
• books.cash_flow's description is the direct method's, shortened to fit the 700-character cap with its dates sentence (tool_descriptions_fit_700_characters, period_tools_describe_the_one_default).

For P12 (D-33; none run): ledger-core calendar::{fiscal_year_start_unclamped, fiscal_year_unclamped, fiscal_year_start_on, period_defaults}, PeriodDefaults::{statement, statement_range, as_of, calendar_year}, PeriodKind::describe, Company::fiscal_year_containing, ChartOfAccounts::set_name, Ledger::{add_account (its new name checks), add_control_account, check_account_name, rename_account, check_rename_account, replay_rename_account, check_rename_reason, check_tax_category_required, check_tax_category_kept}, tax::{needs_category, account_needs_category, uncategorized_accounts, on_form_4797} and tax_summary's Form 4797 section, Settings::require_tax_category; ledger-store Store::{ensure_feature, ensure_features, journal_settings (its feature), add_account, add_account_with_tax, journal_account_added, ensure_control_account, rename_account, set_account_tax, journal_account_tax}, the account.renamed replay and projection arms, format::setting_feature, ops::report_columns; ledger-package statement_range, as_of_date, pnl_statement, bs_statement, cash_flow_statement, year_earnings, build_package's fiscal year; ledger-mcp show (the option refusals, the resolve, the shown wording), show_report_dates, rename_account (its notes), add_account, import_chart_csv (both loops), profit_and_loss_by_class's range, export_journal's period, described, uncategorized_warning, created_uncategorized, the digest's uncategorized_accounts, handbook::period_rule. The viewer is not mutated (owner, 2026-10-18): view_model.rs and show.rs cover it.

P3: parties (defects 14, 24, 11; 2026-10-20)

A party's part of an entry is signed as a line on its own account, with a direction and its money and property; party totals take a basis; money is cash, cards and the financing accounts; a credit to a liability a party is owed itself never pays it; the directory's TIN last four comes from TIN or W-9 facts (rules.md B-35, B-26). Built, reviewed and checked under D-33: no mutation run here; what P12 must cover is at the end.

What	Where	Oracle
The audit's table (F36, F37), row by row: resolved, direction, cash, in kind; reversals the exact opposite; bills and invoices signed; totals on both bases	ledger-core/tests/spec_party_totals.rs defect14_shares_take_the_partys_side_and_reversals_flip	B-35, by hand
Basis all is the members' equity statement, cash the K-1's cash contributions	basis_all_is_the_members_equity_statement_and_cash_the_k1s; property member_totals_are_the_members_equity_statement (members contributing and taking out money and property, alone and jointly, subject to a loan, through 2100 then converted, through their distributions accounts, depreciated property with money, declared to distributions payable and paid later, reversed later in the year; checked over every span from the year's start and, received less paid, over every span)	reports::members_equity, k1::k1_detail
A reversed member card payment nets to zero (brief §1.4)	defect14_a_reversed_member_card_payment_nets_to_zero	B-9
Accruals through another liability count once (defect 24)	defect24_an_accrual_through_another_liability_counts_once	B-35 item 5
A credit to a party's own liability never pays it: a card fee, a distribution owed, a seller's note, property subject to a loan	defect24_a_credit_to_a_partys_own_liability_never_pays_it; the documented limit, pinned: a_distribution_owed_counts_twice_until_the_members_are_named_its_creditors	B-35 item 6; Treas. Reg. §1.704-1(b)(2)(iv)(b)(2); Helvering v. Price
Review, 2026-10-21: a distribution declared to distributions payable counts once, when paid (it counted twice); a distribution of money and depreciated property splits by what moved (the money read as property); a gift card sold is received once (it was a "card": twice); a refund is received; tin_last4 never shows more than four digits	defect24_a_distribution_declared_to_a_payable_counts_once_when_paid, a_distribution_of_money_and_depreciated_property_splits_by_what_moved, defect24_a_gift_card_sold_is_received_once, a_refund_is_received_from_the_vendor, defect11_a_partys_tin_last4_is_its_tin_facts_else_its_w9s (SCENARIO 6)	B-35 items 3, 5; B-26
A mixed contribution splits as the K-1 does, ties to the first member	a_members_mixed_entry_splits_as_the_k1_does	k1 INVARIANTS 3, 4
Read from journaled facts: an archived member, a one-member company	a_members_entry_keeps_its_reading_after_they_leave	review R2
A close is neither; a basis is cash or all; creditor_of's checks; tin_last4's five scenarios; the kernel's cases	a_close_tagged_with_its_members_is_neither, a_basis_is_cash_or_all, a_creditor_is_named_only_on_a_liability_with_one_owner, defect11_a_partys_tin_last4_is_its_tin_facts_else_its_w9s, party_target_cases_by_hand	specs
Properties: a reversal's target, parts and flow are the original's negated; parts sum to the target, each with its sign; a sole party's money part is the flow as before P3; tin_last4 is every source present	a_reversal_is_the_exact_opposite, a_sole_partys_money_part_is_the_flow_as_before, tin_last4_is_every_source_present (PROPTEST_CASES, default 256; 5,000 run clean)	B-35, B-9
Decimal and i64 agree on party_target and reverse_target	kernel_bridge.rs party_target_agrees	the bridge
Kani: the direction is the sign, the target is odd, reverse_target an involution	proofs.rs party_target_direction_is_its_sign, party_target_is_odd, reverse_target_is_an_involution	the kernel spec
The journal: party.creditor_set one line each, under the feature the books declared when created; in books an older version wrote, refused (FormatUpgradePending, nothing journaled) until the format upgrade; refusals journal nothing; books without creditors never change, in either format; corrupt lines refused	ledger-store/tests/party_creditors.rs	the format gate
Over the MCP: get_entry's direction, cash, in_kind; party totals by basis, echoed, others refused; basis all equals members' equity; creditor_of round trips and a card fee isn't a payment; the post_entry preview's parts are what it posts	ledger-mcp/tests/spec_party_totals.rs	the tool docs
Defect 11 over the MCP: a member's TIN last four in the directory, a W-9's, none, after a purge	ledger-mcp/tests/spec_vault.rs defect11_the_directory_shows_a_members_tin_last4	B-26
The viewer shows the tools' numbers, labelled cash basis, with the in-kind line; its what-for reads a reversal as parties::flow does	ledger-gui/tests/parties.rs the_party_page_shows_the_basis_and_in_kind, a_reversed_member_card_payment_is_nothing_on_the_issuers_page	activity_with, flow
bookspec	bookspec/examples/p3-party-*.toml	the same cases, by hand

For P12 (mutation targets, none run, D-33): kernel::party_target (each branch, the != 0 and < 0 tests, the property and money clamps, the neither-when-nothing-counts test), kernel::reverse_target and Direction::{flip, of}; shares::target (the closing check, the reversal arm and its parity, members_only, the equity filter and the retained earnings exclusion, the property test, the own sums), shares::split (the member-order tie-break, the cash shortcut, the zero sign); parties::{flow, root_original, money_accounts, card_accounts, MoneyAccounts::for_parties} (the negation of what_for, the walk's guard, cards and financing as money, the gift-card exclusion); activity_with (the target before the split, the skip of nothing-counts, the bucket by side and basis, the overflow checks); Activity::totals; Basis::parse; Ledger::{set_party_creditor, check_set_party_creditor, creditors_of, is_closing_entry}; Store::{set_party_creditor, ensure_feature}; the server's parse_basis, party_activity, entry_parties_out (direction, cash, in_kind) and update_party's creditor_of diff; the viewer's party_what_for and share_text. Expected equivalent: Party::tin_last4's or_else order swapped (TIN facts and W-9 facts never disagree, parties INVARIANT 2a, enforced on replay).

P3: 1099s (defects 23, 12 and 18; 2026-10-20)

The 1099 decision kept as a decision (nec, misc, not_reportable with its reason kind and words, undetermined), with who decided and the date it takes effect (D-40); payment methods and the tag on each payment; one report for the server, the package and the viewer (rules.md B-19). No mutation run (D-33); the list P12 must cover is at the end.

Law (rules.md B-19)	Tests
Undecided is not "not reportable" (defect 18)	undecided_is_not_not_reportable
"No 1099" is a decision with who and when; "none" refused (defect 23)	a_vendor_marked_no_1099_is_not_undecided, the_cutovers_reasons_are_recorded_as_given, set_vendor_1099_says_what_a_decision_needs (ledger-mcp spec_1099.rs)
A member's card is excluded, their check counts, unknown is undetermined (defect 12)	a_members_personal_card_payment_is_not_a_1099_payment, payments_come_from_cash_and_financing_only
Card-account payments are listed, not dropped	card_account_payments_are_listed_not_dropped
A bank payment counts unless tagged with a card (D-40)	a_debit_card_payment_from_the_bank_is_excluded_when_tagged
A tag describes one account (review R2)	a_tag_naming_another_account_is_undetermined
Money between the company's own sources pays no one (R1)	paying_down_a_financing_liability_pays_no_vendor, paying_the_card_bill_pays_no_vendor
Unknowns never settle the status (R3)	a_negative_unknown_keeps_a_reportable_vendor_undetermined
Money from a vendor for anything but a refund doesn't lower its 1099: a sale, its invoice paid, a disposal, a loan (R6)	a_sale_to_a_contractor_does_not_lower_its_1099, money_from_a_vendor_that_is_no_refund_does_not_lower_its_1099, unit the_other_receipts_note_says_what_each_entry_did (ledger-package)
Cash accounts named, dollars (R5, R16)	the_report_needs_the_cash_accounts_and_dollars
A shared payment splits across buckets to the cent (R12)	a_shared_payment_splits_across_buckets_to_the_cent, unit a_vendor_share_splits_across_buckets_to_the_cent
Dated decisions (D-40)	a_status_change_mid_year_applies_by_payment_date, an_incorporation_on_december_30_is_a_new_vendor, an_llc_electing_corporate_taxation_keeps_its_vendor, a_dated_decision_records_a_change, a_decision_change_names_the_payments_it_reaches, an_undated_old_decision_is_in_force_from_the_beginning, two_status_changes_in_a_year_and_a_reversal_across_them, unit dated_decisions_take_effect_on_their_dates
A change for a closed or due year warns (D-40, R15)	a_change_reaching_a_filed_year_warns (spec_1099.rs)
The bucket table, all 16 cases; splitting and netting exact	payment_bucket_is_the_table_in_all_16_cases, buckets_net_money_moved_between_the_companys_sources, Kani payment_bucket_is_the_table, payment_split_is_exact, net_buckets_keeps_the_total, bridge payment_buckets_agree
Properties	no_instruments_no_financing_is_the_old_report (the regression: with cash named and no methods or financing, the old figure exactly), buckets_partition_each_payment, a_reversal_nets_every_bucket_to_zero, the_worksheet_ties_to_the_ledger (paid + excluded + undetermined + not reportable + receipts for something else = every payment line in the year, dated decisions, sales and receipts included; the payment lists sum to their columns)
Payment methods: refusals, the reversal chain	a_payment_method_is_refused_unless_sound, a_payment_method_tags_the_whole_reversal_chain, unit tests in instruments.rs
W-9 flag kept apart from the decision (brief 1.5, R8)	set_vendor_1099_keeps_the_w9_flag_when_omitted, set_w9_keeps_the_1099_decision_and_its_source, set_w9_asks_for_the_w9_flags_feature_before_its_first_line (spec_1099.rs: refused whole in P2's books until their upgrade), marking_a_w9_keeps_who_decided_the_1099 (ledger-store tests/form1099.rs)
Journal: lines written only under their features (refused, nothing journaled, in books an older version wrote until the format upgrade; never declared on the way); replay and projection exact; refusals and no-ops journal nothing; newer values newer; old books as they always meant	ledger-store tests/form1099.rs (each_feature_waits_for_the_upgrade_and_is_never_declared_on_the_way, decisions_and_methods_replay_and_project, refusals_and_no_ops_journal_nothing, an_unknown_1099_value_is_newer_not_corrupt, books_written_before_decisions_read_as_they_always_meant), unit tests in ledger-store form1099.rs, the op model (refused_commands_never_reach_the_journal with SetVendor1099, SetW9Flag, AddInstrument, SetEntryInstrument; an accepted command journals or changes nothing), books_an_earlier_version_wrote_open_to_its_figures (fixture p2_vendor_1099)
Records change no entry (verification 13a)	decision_and_method_records_change_no_entry
The quieter untagged note (R7)	the_untagged_note_counts_only_money_out (ledger-package)
One builder: the package CSV is the worksheet CSV for the package's accounts; README wording	ledger-package tests/package.rs (the zip's CSV equals vendor_1099_csv for the request's accounts, else the settings', through as_of: payments_to_a_vendor_come_from_the_packages_accounts, one_list_of_cash_accounts_per_package, the_1099_worksheet_stops_at_as_of; the README line pinned); over the MCP, the package's CSV is books.vendor_1099's for the same cash_accounts, financing_accounts and through (ledger-mcp oracle_mcp.rs cpa_package_holds_the_year_and_its_evidence)
The viewer counts as the server does (brief 1.4)	the_viewer_counts_the_1099_as_the_server_does (ledger-gui tests/parties.rs)
End to end, restarting between steps	payment_methods_round_trip_and_classify_payments (spec_1099.rs), mcp_vendor_1099_over_stdio, spec_mcp.rs (every tool exercised and schema-checked, books.instruments read-only)
bookspec	bookspec/examples/1099-*.toml

For P12 (mutation targets, none run): ledger-core form1099.rs (plan_decision, apply_decision, check_new_decision's decided-before test, in_force/in_force_before (< against <=), vendor_1099_report's status branches (each >=, <, max(.,0), min(.,0)), the listing filter, the not-reportable and undetermined routing, the R6 test (< 0, credit side, refund_accounts per account type), Roles::new (which methods' accounts are financing, which a card's), split_share (the floor corrections, the sign), vendor_part, the unresolved fallback, decisions_during, untagged_payments (> 0, each skip, each debit kind), decision_changes); kernel.rs (payment_bucket, split_payment, net_buckets); instruments.rs and Ledger::check_add_instrument (each refusal), set_entry_instrument (the chain), the reversal step's copy, set_vendor_w9_flag; ledger-store form1099.rs (each decode check, newer_content), store.rs (ensure_feature, set_vendor_1099's unchanged path, set_vendor_w9_flag, add_instrument, set_entry_instrument's no-op, the replay and projection arms, sqlite_reversal_chain); ledger-mcp tools/instruments.rs (decision_in's refusals, filed_year_warnings' closed and due tests, resolve_instrument, add_instrument's warnings), server.rs's set_vendor_1099 (the W-9-only path) and set_w9 (the feature declared first, only when the flag changes); ledger-package vendor_1099.rs (the CSV columns, every note's guard, may_file, missing_w9's suffix) and package.rs (tin_gaps, the README line). The viewer has no mutation job (its musts are tested).

P3: parties and 1099s landed together (2026-10-21)

The two pieces above, stacked on the IIF, cash flow and rename pieces, and reconciled where they meet. Built under D-33 (no mutation run); what P12 must cover is at the end.

What	Where	Oracle
One rule for what a card is: the recorded business cards' liabilities, else (none recorded) liabilities named "card", not "gift"; never a member's card, a member's check or a platform; a debit card on the bank is none; money follows it	ledger-core tests/spec_party_totals.rs a_card_is_a_recorded_business_card_else_a_liability_named_card	B-35 item 5, parties::card_accounts INVARIANTS 1-4
Party totals and the 1099 worksheet never contradict: paid less received is the worksheet's paid + excluded_card + undetermined + not_reportable plus its other receipts, for a vendor named alone, whatever the methods, refunds and reversals	property party_totals_are_the_1099s_buckets (ledger-core tests/form1099.rs; PROPTEST_CASES, default 256; 2,000 run clean; dropping a bucket from the sum fails at once)	B-35 item 9, by hand
The same, one year by hand: a member's check, a member's card, a member's payment of unknown method, a company card charge and a company check to one contractor, then the member reimbursed	bookspec/examples/1099-and-party-totals-for-a-members-payment.toml	B-35 item 9; Treas. Reg. §1.6041-1(e)(1), (a)(1)(iv)
The CPA package's 1099 worksheet is books.vendor_1099's CSV for the package's accounts (the request's, else the settings', R18) through its as_of, byte for byte; without through the files differ; a through outside the year and an unknown account are refused	ledger-mcp oracle_mcp.rs cpa_package_holds_the_year_and_its_evidence; ledger-package tests/package.rs payments_to_a_vendor_come_from_the_packages_accounts, one_list_of_cash_accounts_per_package, the_1099_worksheet_stops_at_as_of	B-33; mcp-interface.md
A feature is asked for before a command's first line: books.update_party with a field and the first creditor, in P2's books waiting for their format upgrade, is refused whole (nothing journaled, never the field without the creditor); once upgraded, as in books this version made, it journals the field, then the creditor, declaring nothing	ledger-mcp tests/spec_party_totals.rs update_party_asks_for_the_creditor_feature_before_its_first_line	B-27
One bookspec loader for every example, the parties' and the 1099s' with them: setup.parties, setup.members (distributions_account), setup.payees (a party's vendor record), setup.status_changes, setup.instruments, events' parties and instrument, and the queries vendor_1099, k1, party_part, party_totals, party_tin_last4; refused: a party or payment method not in the setup, a reversal naming parties, party totals without a basis, a 1099 line leaving a figure out, a wrong direction or status	ledger-core tests/bookspec.rs (every_bookspec_example_holds, a_party_not_in_the_setup_is_refused, a_party_parts_direction_is_checked, a_reversal_naming_parties_is_refused, party_totals_without_a_basis_are_refused, a_vendor_1099_line_leaving_a_figure_out_is_refused, a_vendor_1099_status_is_checked, a_payment_method_not_in_the_setup_is_refused)	bookspec/README.md

For P12 (mutation targets, none run, D-33): parties::card_accounts (the recorded-cards branch, the gift and the other-instruments exclusions); ledger_package::Settings::with_accounts (each list's fallback); the server's vendor_1099 (through's year check, the unknown-code check, the accounts passed) and update_party's feature declaration; the bookspec loader's party, payee, decision and payment method setup.

P3: depreciation and schedules (defects 22 and 9, 2026-10-20)

Every expected figure below was worked by hand from the rule (rules.md B-15, B-16) and is written out in the test's doc comment; the fixtures are made up (asset X: 12,000.00 over 12 months from 2026-01-01; a 1,200.00 policy from March 15). Each regression that is an accounting rule is also a bookspec example (bookspec/examples/, P13, D-34).

Law	Test
Through a day of the life's final month, depreciation is prorated by days, never plugged (repro A: December 483.87, accumulated 11,483.87)	ledger-core spec_assets_payroll.rs defect22_depreciation_through_mid_final_month_is_prorated_not_plugged; spec_asset_tags.rs register_as_of_a_day_before_a_same_month_disposal_is_prorated
A mid-month life's drift is spread over the final month's days (repro D: through Apr 13, 920.00; Apr 14, 930.00)	defect22_final_month_drift_is_spread_by_days; spec_replayed_extremes.rs depreciation_reaches_chronos_last_month (1,185.92 through Dec 10 of year 262142)
A disposed asset's schedule stops at its disposal day, held, and equals what the disposal took (repro B)	defect22_a_disposed_assets_schedule_stops_at_its_disposal_day, property prop_disposed_schedule_equals_what_disposal_computed; ledger-mcp spec_assets.rs a_disposed_asset_lists_what_it_depreciated_through_its_disposal
A disposal in the final month posts depreciation by days (repro C: 322.58, gain 322.58)	ledger-store tests/assets.rs defect22_a_disposal_in_the_final_month_posts_depreciation_by_days
A disposal inside a month already run takes back the days after it (R2: excess 500.00, book value 6,500.00)	defect22_a_disposal_inside_a_posted_month_takes_back_the_extra_days (store and ledger-mcp spec_assets.rs)
A month skipped is caught up in the month the run is made; a later run for it posts nothing (settled in design, P3)	core a_skipped_month_is_caught_up_in_the_month_run, store a_skipped_month_is_caught_up_in_the_month_run, MCP a_skipped_month_is_caught_up_and_said
A reversed run is un-posted and runs again (feature month_reposting); re-instating a run whose month ran again is refused; a disposal, and a run its disposal took as final, can't be reversed; a reversed run before a disposal leaves nothing behind (R3)	store a_reversed_depreciation_month_can_be_run_again, a_disposal_entry_cannot_be_reversed, a_reversed_run_before_a_disposal_leaves_nothing_behind; core a_reversed_schedule_month_is_due_again
What the books carry is read entry by entry, each in its own month: a run reversed after its month ended isn't run twice (its month posts nothing; the reversal's month catches it up), for depreciation; a schedule month reversed after it ended is left for a human, listed with why (P3 review)	store a_run_reversed_after_its_month_is_caught_up_in_the_reversals_month; GUI a_run_reversed_after_its_month_leaves_the_reversals_month_due; core schedules.rs a_schedule_month_reversed_after_it_ended_is_left_for_a_human; store format.rs a_schedule_month_posted_again_waits_for_month_reposting_and_replays
Re-instating a run (reversing its reversal) never carries the books past the schedule, nor past cost less salvage (P3 review)	store reinstating_a_run_a_later_run_caught_up_is_refused
What the books carry is each run and each reversal in its own month, alternately adding and taking away (P3 review)	core spec_assets_payroll.rs depreciation_effects_read_each_entry_in_its_month
A schedule month that rounds to nothing is never a posting: left out of a daily plan, never due in an equal-months one (P3 review; no test held it before)	core schedules.rs a_month_that_rounds_to_nothing_is_never_a_posting
A disposal is refused while a later month's run stands, or while an earlier run's reversal is dated after the disposal's month; once undone, the disposal month ends at 0.00 accumulated and its expense whole (P3 review)	store a_disposal_before_a_later_months_run_is_refused_until_it_is_reversed, a_disposal_before_a_later_reversal_of_an_earlier_run_is_refused
A disposed asset's figures in the viewer are what its disposal took (its excess or catch-up from the disposal entry) and none of its months is Due (P3 review)	GUI a_disposed_assets_figures_are_what_its_disposal_took
The final month is C + (D − C) × k / d, rounded half up, against arithmetic written in the test (P3 review)	property prop_the_final_month_takes_the_remainder_by_its_days (500 cases)
A month that rounds to nothing posts and journals nothing (R10)	store run_depreciation_posts_nothing_for_a_month_that_rounds_to_nothing, MCP run_depreciation_skips_a_month_that_rounds_to_nothing
Depreciation and daily schedules round to the currency's minor unit (R1: yen, dinars)	jpy_depreciation_posts_whole_yen, store jpy_depreciation_runs_post_whole_yen, schedules.rs a_jpy_daily_schedule_posts_whole_yen, a_kwd_daily_schedule_rounds_to_the_fils; money.rs steps_are_the_currencys_minor_unit
A new schedule spreads by the day (1,200.00 from March 15: 54.84, eleven 100.00, 45.16); deferred revenue is earned by the day (290.32, 333.34, 333.33, 43.01)	schedules.rs defect9_a_new_schedule_spreads_by_the_day, defect9_deferred_revenue_daily_is_earned_to_the_cent; schedules.rs unit a_daily_plan_spreads_by_the_day; ledger-mcp mcp_stdio.rs mcp_daily_schedule_over_stdio
Schedules from before P3 stay equal months, forever	defect9_legacy_schedules_stay_monthly_even, property prop_monthly_even_plan_is_unchanged; every old-books fixture (books_an_earlier_version_wrote_open_to_its_figures)
An equal-months schedule starts on the 1st (D-37); a daily one's last day is in the calendar	an_equal_months_schedule_starts_on_the_first, spec_bounds.rs a_daily_schedule_whose_last_day_passes_9999_is_refused
chrono's month-end clamping is pinned for daily plans (Jan 29, 30, 31; Feb 29)	schedules.rs unit daily_plans_pin_month_end_clamping
A new asset's cost and salvage are in the minor unit (replay takes finer ones, computed); a life ending 9999-12-31 is taken, a day later refused	spec_bounds.rs an_asset_cost_finer_than_a_cent_is_refused, a_life_ending_on_9999_12_31_is_accepted, a_life_ending_after_it_is_refused
A daily schedule needs feature schedule_convention (books an older version wrote wait for the upgrade); an older reader stops at its declaration; monthly_even needs none; an unknown convention is newer, never corrupt	ledger-store tests/format.rs a_daily_schedule_waits_for_its_feature_and_an_older_reader_stops_there, a_monthly_even_schedule_declares_no_feature, an_unknown_schedule_convention_is_newer_not_corrupt; format.rs unit an_older_reader_stops_at_p3s_features
Accumulated depreciation never falls, never exceeds cost − salvage, is 0 before service and the whole from the last day (sampled days: the first and final months, two between, a dozen month ends; R9)	property prop_depreciation_is_monotone_and_bounded (500 cases)
No posted month moves but a half-cent tie's cent (old Decimal arithmetic as the oracle)	property prop_month_end_schedules_match_the_legacy_arithmetic_except_half_cent_ties (500 cases)
A daily plan sums exactly, lands on month ends, each amount > 0; from the 1st, months postings within a cent of total/months	property prop_daily_plan_sums_exactly_and_lands_on_month_ends (2,000 cases)
Refused commands never reach the journal, now with daily and monthly_even schedules and zero-month runs	ledger-store tests/store.rs refused_commands_never_reach_the_journal
Every order of runs, reversals (any day, before an entry's own included), re-runs, re-instatements, disposals and closes on one asset keeps the books right: refusals journal nothing; at every month end before the disposal the expense is the accumulated depreciation and within the schedule; one run in effect per month; a disposal's month and the end at the schedule through its day, accumulated 0.00, the gain proceeds less book value; an active asset run month by month past its life takes exactly cost less salvage (P3 review round 2)	store asset_orders.rs every_order_of_runs_reversals_disposals_and_closes_keeps_the_books_right (exhaustive, three commands deep; four and five with WB_ORDERS_DEPTH, run clean 2026-10-21), prop_any_sequence_keeps_the_books_right (64 cases, up to 9 commands, any day)
The viewer reads an asset as the store does, whatever the runs, reversals and disposals: what the books carry, each finished month's status against a run of it, what is unposted (P3 review round 2)	GUI prop_the_viewer_reads_an_asset_as_the_store_does (48 cases), the_viewer_counts_a_run_reinstated_after_its_rerun_was_reversed
A run re-instated after its month was run again and that run reversed still counts: in the store, the disposal and the viewer (P3 review round 2; before, the projection's row named the reversed re-run)	store a_run_reinstated_after_its_rerun_was_reversed_still_counts; GUI the_viewer_counts_a_run_reinstated_after_its_rerun_was_reversed
A depreciation run's or schedule month's reversal can't be dated before the entry it reverses (P3 review round 2: a run of March reversed on Jan 31, then a disposal on Feb 15, ended February with a 1,000.00 debit in accumulated depreciation)	store a_reversal_dated_before_the_entry_it_reverses_is_refused
A disposal waits only until what the runs carry at its month's end is what they carry now, so a late change undone after its month closed lets it through (P3 review round 2; round 1 refused it for ever)	store a_disposal_is_taken_once_a_late_change_is_undone_after_its_month_closed
Depreciation still due when the disposal's month has a run is charged in the disposal entry, never as a second run of the month (P3 review round 2; no store test held it)	store a_disposal_whose_month_has_run_charges_what_is_still_due_in_its_entry
A command that needs a journal feature asks for it before its first journaled line: in books waiting for the format upgrade it is refused and journals nothing, and after the upgrade it is taken	store format.rs a_write_waiting_for_the_upgrade_journals_nothing
What a viewer's one pass says a run of each month posts is run_amount's for that month	property prop_run_amounts_are_each_months_run_amount (500 cases); Kani catch_ups_is_every_suffixs_catch_up
The kernel on i64 and i32 (Kani's) is the kernel on i128 and Decimal (the engine's)	kernel_bridge.rs prorate_agrees_at_i64_and_i128, prorated_through_agrees_at_i32_and_i128, catch_up_and_true_up_agree
The charge never falls and is continuous at month ends, over every 1-to-3-month span from every day of a common and a leap year	kernel.rs unit the_charge_never_falls_and_is_continuous_over_real_calendars (exhaustive)
Proofs	Kani prorate_parts_sum_to_total, prorate_last_part_absorbs_the_remainder, a_months_charge_is_within_half_a_cent, a_months_charge_in_tenths_is_within_half_a_cent, the_last_months_charge_is_within_half_a_cent, the_last_months_charge_in_tenths_is_within_half_a_cent, prorated_through_refuses_malformed_input, catch_up_never_overtakes_the_schedule, catch_ups_is_every_suffixs_catch_up, true_up_reaches_the_target; Lean Prorate.lean (cum_mono, cum_le, cum_full, parts_telescope, prorate_total, prorate_nonneg, part_within_a_unit, roundUnit_near, roundUnit_scale, cum_near, part_near, chargeMid_eq_cum, chargeLast_eq_cum, chargeLast_start, chargeLast_mono, kernel_parts_total, kernel_parts_nonneg; docs/verification.md)

Mutation targets for P12 (none run in P3, D-33): kernel.rs prorated_through (the last/not-last branch, the rounding comparison r >= step - r against >, the k == days && last shortcut, the cap at the total, every refusal), round_to_unit, prorate_by_days, part_weight, MonthPart::is_valid, the three Units impls, catch_up, catch_ups, true_up; calendar.rs month_parts, days_in_month, next_month_start; money.rs Steps::of, Steps::decimal; assets.rs schedule_months (the stop date's min with the disposal day, the inclusive + 1, the partial-month break), life_end, check_disposal, run_amount, catch_up_room, depreciation_effects (the chain's alternating signs), run_amounts (its stop past the life), cumulatives; ledger.rs check_new_asset (the minor-unit checks, the pred() bound), check_reversal SCENARIO 5, in_effect, reverse_entry_steps' schedule un-posting, schedule_month_posted_before, schedule_month_reversed_after, schedule_month_hold; schedules.rs daily_plan, plan_for, validate_schedule (the 1st rule, the daily bound, the minor-unit plan check), first_day, last_day, next, due's zero months, ScheduleConvention::parse/key; settings.rs the new key and schedule_convention()'s default; store.rs run_depreciation (nothing due, the feature on a re-run), live_runs, Ledger::depreciation_runs (was depreciation_runs_ever), dispose_preview (true-up split, in_month), check_nothing_after_disposal, disposal_lines, check_reverse_entry (the re-instatement room), register_schedule (the feature only for daily), ensure_feature, post_schedule_month's feature, run_schedules' held months, the schedule.registered replay arm's convention, the asset.depreciation_posted projection upsert, period_month; format.rs KNOWN_FEATURES, declared_knowing; server.rs create_schedule's default resolution, schedule_out's new fields, run_depreciation's skips, list_assets' schedule_error, dispose_asset's debits, run_schedules' held months; ledger-gui books.rs disposal_true_up, pages/assets.rs unposted and schedule's disposed months. Equivalent mutants foreseen: none (r >= step - r against > is killed by half_a_unit_rounds_up).

P3: the format upgrade (2026-10-20)

D-39 and plan/served.md 3.9 (format_upgrade_pending): books an older wanderbooks wrote wait for the owner's go-ahead before they move to this version's journal format (rules.md B-27). Mutation testing waits for P12 (D-33); the targets are listed at the end.

• ledger-store format.rs unit tests: this version's format is the newest with every known feature; books wait exactly when behind (a synthetic version with features covers what main can't yet: features missing one at a time, all added at once, a format ahead never "behind"); a write needs what the books declared, and the refusal names the guard, says nothing changed, and that only the owner can agree; a reader that doesn't know a declared feature still refuses it as newer.
• ledger-store tests/format_upgrade.rs: new books declare the format as they are created; older books open without a byte changing, a change needing format 2 (settings, a convention, an open item) is refused journaling nothing while a change needing nothing new is made, the upgrade is one line with the whole format, again nothing, the figures unchanged; every old-books fixture (30) upgrades, verifies as it did and replays to its expected.json in the writer, reopened, and the viewer; a declared newer feature is still refused as newer. tests/settings.rs (a_change_needs_journal_format_2, the lazy declaration it replaces), tests/root.rs (an adoption's copy moves to this version's format; the source keeps its own), tests/format.rs (its books are format 1, as before the gate).
• ledger-store tests/schema_files.rs (each projection schema in a file of its own, the lead's decision of 2026-10-21): a P2-shaped books dir (tests/fixtures/p2-books, its wanderbooks.db at schema 12, written by write_the_p2_fixture while this code's schema was P2's) used as it is at its schema and left byte for byte, and whole, past it; a legacy file one schema older than this version's, on every version, left byte for byte and whole for its schema while this version's is built from the journal and kept up, the report and the viewer naming the one in use; a newer schema's file, under its own name or the legacy one, left alone, never refused; this version's own damaged (not a database, or holding another schema) kept aside and rebuilt, a damaged legacy one left; new books' file named for its schema. Checked by breaking it (the legacy file always taken, the schema check dropped): three tests fail. The store's other tests use db_file(), this version's file.
• ledger-store backup.rs: the_archive_proves_to_hold_the_book_as_it_is_keys_and_all (a changed or extra key, a changed vault record, books that moved on, a journal changed under the recorded head: each refused; the scratch folder always removed).
• ledger-mcp local.rs: format_upgrade_waits_for_consent (listed as waiting; no passphrase set, a wrong one or none refused before anything is done, no backup, no line, still served; with it, the backup is the archive's latest commit, holding the journal as it was and the key; one line, the whole format; on the backup record; again, nothing; new books wait for nothing, and asking for their upgrade makes not even a backup repository), no_upgrade_without_a_backup (a backup refused: nothing upgraded, still waiting, recorded) and no_upgrade_unless_the_backup_just_made_is_proven (an archive whose head names another branch takes the commit where no clone finds it: what is proven isn't what was made, nothing upgraded, both recorded; put right, the latest commit, which already holds the books, is proven and the upgrade made). Each checked by breaking the code it guards (the proof skipped, the made-is-proven check dropped, the early return for books that wait for nothing removed): the test fails, then passes once restored.
• ledger-cli tests/format_upgrade.rs (the plan's format_upgrade_waits_for_consent, from end to end through the one executable): a command not at a terminal says the books wait; books list and doctor say so; books.start names it and puts the handbook's format-upgrade section first; books.set_setting refused with the guard, journaling nothing, while adding an account works; no tool's name could consent, and no call moved the format; books upgrade refused off a terminal; the lease intent with a wrong passphrase refused; at a terminal an empty passphrase declines, and books list asks at each of two opens, while one whose output goes to a file only notes it on the terminal and asks nothing, its output its own; with the passphrase, the backup (journal as it was, the key) then one line, the agent's same session then sets the setting and verifies; asked again, nothing.
• ledger-gui tests/format_upgrade.rs: the dialog at open and at the next open, "Not now" leaving the standing notice (whose button, and the Books menu, ask again), the viewer writing nothing; nothing sent without a passphrase, the one typed handed to the owner as typed, a refusal said in the dialog, which stays, the right one closing it; books in this version's format and older books dirs never asked; an upgrade whose worker dies without an answer is said in the dialog, which can then be closed (never left at work, holding the window). Screenshots looked at (SHOT_DIR=... cargo test -p ledger-gui --test format_upgrade screenshots): the dialog over the overview, at work, refused, the notice, the menu item, done.
• Unit tests in admin.rs (the passphrase never in Debug; the request's shape), ledger-host lease.rs (a_consent_never_shows_its_passphrase: the lease intent's Debug, and the line's, name no passphrase), and owner_menu.rs's fake owner takes the new call.

For P12: ledger-store format.rs (current, upgrade_to, adds, require_format, require_feature), store.rs (create_in_format, ensure_format, ensure_feature, upgrade_format), root.rs (adoption's upgrade and its verify), backup.rs (prove_archive, held_files); ledger-mcp backup.rs (upgrade_format, UpgradeFailed::parts), local.rs (upgrade_format, the List's format_upgrade, waiting), server.rs (with_store_mut), tools/kept.rs (the first next step, format_upgrade), admin.rs; ledger-host host.rs (consent, consented), commands.rs (consent_now, upgrade_format, offer_upgrades, offer_upgrade, upgrade, book_line, upgraded_lines, upgrade_explained, ASKED_UPGRADES). None run.

P3: asset basis and tax-basis capital (2026-10-20)

Defect 13 (assets: posted vs scheduled, the in-service and acquired dates, the contributed property's bases) and D-41's K-1 worksheet on the tax basis. Mutation runs wait for P12 (D-33); none was run.

• Named regressions (the brief's reproductions, anonymized): list_assets_book_value_is_what_the_books_carry and a_reversed_run_is_not_posted (ledger-mcp/tests/spec_assets.rs), an_asset_bought_before_it_is_in_service_is_on_the_register_from_acquisition, personal_use_contribution_keeps_its_723_basis_apart_from_depreciable_basis, built_in_gain_is_fixed_at_contribution_not_book_cost (ledger-core/tests/spec_asset_basis.rs, which replaces spec_tax_basis.rs). Each is also a bookspec example (bookspec/examples/assets-*.toml).
• ledger-core: spec_asset_basis.rs (every AssetBasis::check refusal and its replay pairs, the figure table for each rule, legacy records giving the figures they gave, the four-contributed-devices shape, the acquired date from the link and its refusals, the disposal floor, accumulated_posted and its edges: a run dated after as_of, a reversal dated after it, a reversal dated before its run, a reinstated run, disposal on and after as_of, check_depreciation_run and record_depreciation_run); tax_capital.rs (tax-basis capital per member with a cash contribution, a contribution of property, a distribution and a year of depreciation; next year's beginning; cash-only books, whose tax income is still the return's; property without a basis; property distributed; the roll-forward and reconciliation over spans; and, from the P3 review, four devices and a prepaid plan by hand (two worth less than basis, one more, one equal; the plan at book with its note; the gain property's disposal flagged with its built-in gain), property subject to a liability (negative tax property), and three members with unequal shares, one contributing nothing); spec_asset_basis.rs a_duplicated_run_line_is_carried_once; properties.rs prop_basis_figures_laws (5,000 cases); kernel_bridge.rs basis_figures_agree; Kani basis_figures_laws (src/proofs.rs, 83 checks, its cover satisfied); spec_asset_tags.rs (the register's posted and scheduled figures, runs recorded as a store records them).
• ledger-store: asset_tags.rs (asset.basis_set journaled under the feature asset_basis (new books declare it as they are created), replayed, reloaded from the database and rebuilt, and in the viewer; a line whose figures disagree with today's formula still replays; an unknown rule or method is newer, a malformed figure corrupt; pre-P3 asset.tax_basis_set lines give the figures they gave; P2's v12 database left as it is while this version builds its v14 file, runs keyed by entry (a_p2_database_is_left_and_this_versions_built_from_the_journal); a v13 file as it shipped before the basis columns left too and v14 built (a_v13_file_built_before_the_basis_columns_is_left_and_rebuilt; schema_files.rs a_shipped_migration_never_changes); v9 and v10 databases under this version's name rebuilt). The old books (books_an_earlier_version_wrote_open_to_its_figures) open to exactly their figures.
• ledger-mcp: spec_assets.rs (the aliases purchase_date, in_service, tax_basis_rule, contributor_basis and the old rule names, noted, and refused when they disagree; the acquired date from the acquisition entry; a value at contribution required; every refusal changing nothing; list_assets as of a date, disposed and not yet acquired; the register export's columns and totals).
• ledger-package: package.rs the_k1_worksheet_reports_tax_basis_capital (the CSV line by line).
• bookspec: the one loader (ledger-core/tests/bookspec.rs) runs the assets' examples in the shared shape: setup.assets with acquired_by and basis, a [[changes]] correct_asset, and the queries register_row, register_totals, asset_basis, k1_tax_basis and k1_reconciliation (keyed "<member>.<line>", beside k1's book figures); refused: a register row before the asset was acquired (a_register_row_before_the_asset_was_acquired_is_refused), an acquired_by naming an event with no entry (an_asset_acquired_by_an_event_with_no_entry_is_refused), a figure for a tax line the books can't know (a_tax_line_the_books_cant_know_is_open) and a member's reconciliation leaving a cause out (a_members_reconciliation_shows_every_cause).
• ledger-import: asset_register.rs (pdf_shows_723_and_depreciable_basis and the other PDF checks) and spec_import.rs (XLSX columns, totals, reconciliation and notes).
• ledger-gui: tests/assets.rs (basis_figures_are_ledger_cores, journal_text_names_each_basis_figure, the "Confirm its value" and "Choose a §704(c) method" items); pages/assets.rs (an_assets_page_shows_its_own_book_value: cost less posted, the schedule beside it); pages/reports.rs (asset_register_report_carries_tax_basis).

For P12 (mutation targets): kernel::basis_figures (min for max, the sign of the gain, purchase to a contribution); Ledger::accumulated_posted and assets::run_chain_entries (<= for < on the entry and reversal dates, the disposed → 0 branch, the alternating sign); live_depreciation_run's reversal test; check_depreciation_run's arms; the register filter acquired <= as_of and asset_acquired_date's min; AssetBasis::check, check_journaled and check_legacy_journaled arms; the acquisition and in-service date refusals; the disposal floor; the MCP aliased logic (both given and differing); asset_basis_from_journal (newer vs corrupt); the projection loader's two key sets; tax_capital::share and entry_property (the mismatch branch, the unknown sum), the open-item conditions (in_service, the disposal window), and the reconciliation's signs.

P3: the seams between the pieces (2026-10-21)

One year of fictional books for a two-member LLC, built through the real Store (ledger-package/tests/seams/books.rs: cash and property contributions, member-paid expenses through Due to Members and their reimbursement, card purchases and payments, a daily prepaid, a 1099 contractor paid by check, card and a member's check whose status changes mid-year, a refund, a loan, depreciation with a run reversed and caught up, a disposal that credits back part of a month's run, a distribution declared then paid, monthly closes with odd cents), checked on June 30, September 15 and December 31: the same fact from two pieces agrees, or rules.md says why not. Mutation runs wait for P12 (D-33).

• Engine (ledger-package/tests/p3_seams.rs): the_members_figures_agree_on_every_date (members' equity, the K-1 worksheet, party totals on both bases, the cash flow's contributions, advances and distributions, B-35 items 4 and 8), a_distribution_declared_then_paid_is_financing_when_paid, the_1099_worksheet_ties_to_party_totals_and_the_ledger (B-35 item 9, B-19), depreciation_is_one_figure_everywhere (the P&L, the cash flow add-back, the tax-basis K-1's open item, the IIF, the register posted and scheduled, the balance sheet), every_statement_foots_on_every_date, the_cpa_package_as_of_each_date_is_the_tools_figures (B-33).
• Viewer (ledger-gui/tests/p3_seams.rs): its capital statements, party money, cash flow, register and 1099 worksheet, read from the books' folder and settings file as it opens them, are the engine's.
• Tools (ledger-mcp/tests/p3_seams.rs, the real binary over stdio): books.cash_flow line by line, books.profit_and_loss, books.export members_equity and iif, books.list_assets, books.vendor_1099 through each date, books.party on both bases.
• Found and fixed (each test fails before its fix): a distribution declared to a payable and paid later read as cash paid to suppliers (B-14 rule 2; a_distribution_declared_then_paid_is_a_distribution_paid in ledger-core/tests/spec_cash_flow.rs, with the property prop_cf_financing_is_equity_plus_designated_debt's model extended); a disposal's depreciation credit-back was in the cash flow's gain or loss, not its depreciation (B-14 rule 8; a_disposals_depreciation_credit_back_is_depreciation), and the tax-basis K-1's book depreciation left it out (B-36); books.list_assets as of a day said "disposed" for a later disposal (B-15 rule 8).

P3: the surface review (2026-10-21)

The agent's surface, the docs and the whole proof run, on main with all of P3 landed (first 2f999c6, then rebased onto 2c5b5a7 with the seams, asset basis and data safety reviews, and checked again). No mutation run (D-33). What was run, in this order, each alone (under taskset -c 4-15, four build jobs, on a laptop other work kept at a load average near 30): just check (clean, before and after the fixes); just prove as it stood (it ran past its 30-minute cap at four jobs, 52 of 53 harnesses verified: see docs/verification.md, "Running it"); just prove and just prove-slow after the split, until both passed; the viewer's screenshots on the demo books; the privacy sweep below.

What	Where	Oracle
Every tool the server has is documented in docs/mcp-interface.md, and every tool the doc documents exists (115; books.access_log had no entry)	ledger-mcp server.rs every_tool_is_documented_and_every_documented_tool_exists (with a check of its own reader)	the doc, read tool by tool against the code
The reversal's cash flow mirror at three lines, in two halves: a reversal's movements are its original's negated, and kernel::flows_of is odd; end to end at two lines	Kani entry_movements_of_a_reversal_mirror, flows_of_mirrors, entry_flows_of_a_reversal_mirror (kernel::entry_flows split into entry_movements and flows_of, behavior unchanged: every cash flow test, bridge and property passes)	docs/verification.md law 10; Lean flows_reversal
A closed-list value in a bookspec example (a 1099 form, a payment method's kind, a reason kind, a party totals basis) is spelled exactly as the README spells it; a K-1 query needs cash_accounts	ledger-core tests/bookspec.rs a_form_in_another_case_is_refused, a_payment_method_kind_in_another_case_is_refused, a_reason_kind_in_another_case_is_refused; check_k1	bookspec/README.md
Every Kani harness in src/proofs.rs runs in exactly one of just prove and just prove-slow, each run's count is checked, and a slow-list name that isn't a harness fails	justfile _kani	docs/verification.md, "Running it"

Docs corrected (each against the code): docs/mcp-interface.md, about 60 fixes (parameter names: search_entries' account_id, link_receipt's attachment_id; outputs: books.chart, books.digest, get_receipt, run_recurring, label_asset, asset_schedule, dispose_asset, import_bank_csv; refusals: reverse_entry's date rule, create_schedule, renumber_account, register_asset, correct_asset, set_vendor_1099, set_entry_party, withdraw_attachment; the idempotent list (ten, not seven), the handbook's section list, books.start's next steps, the receipt policy's keys, the export reports and formats, the CPA package's files, the close's targets, stale "out of scope" text); tool and schema text in server.rs and types.rs where it said the same wrong things; rules.md cross-references (eight wrong B-rule numbers in code, tests and one example); bookspec's README (what the loader takes, the statuses defined) and thirteen examples' statuses (an example whose figures follow an owner decision is CHOICE and cites it); docs/verification.md (laws numbered 1 to 31, no gaps; every harness listed with its law, recipe and time); README.md's tool count.

Privacy sweep (after the rebase onto 2c5b5a7). scrubber.originals_left over every tracked file (626, binaries decoded too): none in any text file or fixture (the P2 served-books fixture's journal, database and vault included); the six Inter font files match only a descending digit run in their TrueType bytecode, a placeholder number the scrub's map also holds, not a TIN from the books. The first company's people, places and bank, by name (case-insensitive, LICENSE files aside): none. The eighteen figures from its books, with and without thousands separators: none.

The viewer (the demo books, cargo test -p ledger-gui --test screens, every page; PNGs kept outside the repo): the figures tie across pages. Fixed: a report's notes were drawn on one line and cut (the fixed asset register's explanation of its tax columns ended mid-word); they wrap over the table's width now. The Accounts page listed each type's accounts in the order they were added; it lists them by code, as the reports do.

For P12 (mutation targets, none run): kernel::entry_movements and kernel::flows_of (the split of entry_flows; the same mutants as before); the bookspec loader's exact-spelling filters and check_k1's cash_accounts check; documented_tools (its own sample checks it). The earlier P3 sections' lists stand (one name corrected: Ledger::depreciation_runs, which was depreciation_runs_ever).

P3: projects (2026-10-21)

The owner's ask: "a Projects page that treats a class as a project ... Projects are entities too", a company rule to link things to projects (the convention link-to-projects), and the sidebar's links drawn under the status box in a short window (rules.md B-37). Mutation runs wait for P12 (D-33); none was run.

• ledger-core: tests/spec_projects.rs (project_facts_default_for_a_bare_class, set_project_checks_every_field, set_project_renames_the_class_and_moves_no_figure, add_class_refuses_a_duplicate_name, replay_set_project_takes_what_the_text_rules_would_refuse, project_figures_are_its_tagged_lines, project_to_date_ignores_the_start_and_the_projects_dates, a_tagged_balance_sheet_line_counts_nothing, closing_entries_are_left_out_of_project_figures, a_reversal_nets_a_project_to_zero, unrecovered_cost_only_for_on_spec_and_never_negative, projects_of_party_lists_them_by_name, check_decision_refuses_an_unknown_or_repeated_project, differs_from_names_projects, names_compare_one_way_for_the_duplicate_check_and_the_lookup, old_books_duplicates_resolve_to_the_lowest_id_and_change_freely, an_unchanged_name_is_kept_exactly_and_not_checked_again, a_name_of_digits_only_is_refused, a_link_is_read_as_a_web_address_for_a_full_tin); properties.rs prop_project_nets_partition_the_pnl (random tags on both lines of random entries, a random period: the projects plus the untagged lines are the P&L, and each project's months sum to its period) and prop_project_entries_sum_to_the_net_to_date (project_entries' own signs: the posted entries' project amounts are the net to date, with refunds, reimbursements, tagged cash lines and drafts beside them); Kani unrecovered_cost_laws (src/proofs.rs, docs/verification.md law 32, run by just prove: never above max(expenses, 0) when revenue isn't negative; the earlier "never above expenses" fails it, checked).
• ledger-store: tests/projects.rs (add_project_journals_class_added_then_project_set, a_name_only_project_journals_class_added_alone, project_writes_wait_for_the_upgrade_and_journal_nothing, update_with_nothing_new_journals_nothing, project_set_replays_verifies_and_reloads, an_unknown_status_or_kind_is_newer_a_malformed_record_corrupt, a_decision_without_projects_writes_the_bytes_it_always_did, attachments_link_to_a_project_and_unlink, old_books_open_to_their_figures_with_projects_known (each fixture's report snapshot and verify against its expected.json), format_2_books_without_the_feature_wait_for_it_alone (the live books after install: format 2, every earlier feature, not projects), old_books_with_a_duplicate_name_change_either_project, a_fact_only_change_never_renames_an_untrimmed_old_name, and the proptest prop_project_set_round_trips); tests/format.rs p3_features_wait_for_the_upgrade_and_are_declared_once gains projects and a project.set.
• ledger-mcp: tests/spec_projects.rs (add_project_then_project_returns_its_facts_and_figures, a_name_only_project_journals_only_class_added, update_project_checks_every_field_before_writing, update_project_with_nothing_new_journals_nothing, project_figures_match_profit_and_loss_by_class, project_to_date_counts_lines_before_the_period, on_spec_project_shows_unrecovered_cost_and_others_null, project_lists_entries_documents_decisions_and_party, link_attachment_to_a_project_by_name_and_id, file_document_with_a_bad_project_files_nothing, record_decision_names_projects_and_decisions_filter_by_project, party_lists_its_projects, start_lists_active_and_paused_projects, show_project_sends_its_target, project_writes_wait_for_the_format_upgrade, add_line_notes_a_finished_project, record_payout_notes_a_finished_project, a_name_resolves_as_the_duplicate_check_compares, old_books_duplicates_take_fact_only_changes, a_digit_name_that_shadows_an_id_says_what_to_pass); hostile_args.rs a_project_over_the_whole_calendar_answers_quickly and books.projects among the read-only calls; spec_vault.rs's idempotent list gains books.update_project; the unit tables (annotations_complete, scopes' table) list 119 tools, period_tools_describe_the_one_default checks the period tools' wording, and mcp_stdio.rs's tools/list shows 116; every_tool_is_documented_and_every_documented_tool_exists holds with the four new tools (on the rebase onto the surface review it caught books.list_classes written mid-line and a books.set_line_class the doc named, which is no tool). ledger-store tests/format.rs the_replay_fuzzer_writes_every_event_type caught project.set missing from fuzz_store_replay's types; it and the project fields are in them now.
• ledger-gui: tests/projects.rs (projects_page_lists_every_project_alphabetically, project_figures_are_ledger_cores, unrecovered_cost_shows_only_on_spec, a_project_row_opens_the_project, an_entry_row_opens_the_entry, a_document_opens_the_document, the_party_link_opens_the_party, profit_by_project_bar_opens_the_project, party_page_lists_its_projects, entry_line_project_opens_the_project, journal_describes_project_set, show_project_target_opens_its_page, a_long_link_stays_in_its_card (200 characters, 1440 and 900 wide), a_long_name_keeps_the_page_in_the_window (with spaces and without), a_long_party_name_keeps_to_its_card, a_month_bar_opens_nothing_and_margin_keeps_one_place, an_entry_without_receipts_says_nothing_of_them; with SHOT_DIR set the edge pages are saved as PNGs); charts.rs a_crowded_chart_keeps_its_years and a_view_only_chart_shows_figures_and_takes_no_click; old_books.rs old_books_classes_read_as_projects and every project page over the old books; read_only.rs renders the Projects list and every project page over read-only books (what the brief called visiting_project_pages_changes_nothing); breadcrumbs.rs a project's crumbs. The sidebar: edges.rs sidebar_links_never_draw_under_the_status_box (1440x500, scrolled to the end: Journal ends above the status box), rail_links_never_draw_under_its_footer (900x420) and a_normal_window_shows_every_link_unscrolled (1440x920); both short ones fail on the code before the fix (checked by putting it back); a_very_short_window_keeps_one_link (1440x220, 900x200: a link stays whole above the footer, which gives way off the bottom). The sidebar links, painted table rows and bars now carry accessible names, which the tests find them by. Shots before and after: ~/.cache/wanderbooks/shots-p3-projects/ (before-*, after-*, final-*, and the project pages light, dark, 1100 and 900 wide).
• bookspec: setup.projects, a line's project, and the query project; examples projects-net-is-its-tagged-lines and projects-on-spec-costs-are-expenses; refused: a_project_named_twice_is_refused, a_line_naming_an_unknown_project_is_refused, a_project_query_leaving_a_value_out_is_refused.

For P12 (mutation targets): check_set_project's arms (ended_on with active/paused, < vs <= on the dates, the duplicate name's self-exception, case folding) and ProjectFacts::check (the link limit, whitespace, duplicates); kernel::unrecovered_cost (max, the sign); project_figures' class filter, its 240-month window and the closing-entry exclusion; project_entries' normal-side sign and the balance-sheet zero; project_set_of (newer vs corrupt); Store::add_project's "facts beyond the default" test (one line vs two); set_project's unchanged short-cut; subject_feature; check_link_to's feature check; the decision projects omit-when-empty; late_tag_note's is_over; remember_footer's threshold.

P3: the project snapshot (2026-10-22)

The owner's ask: a "mini financial snapshot" of one project on its page, overhead left out, so it shows at a glance whether the project is in the black or the red, with charts (rules.md B-37 item 7: contribution before overhead, revenue less every traced cost, a segment margin in Garrison's sense; a presentation choice, not GAAP). Every figure is ledger-core's: ProjectToDate::{net, margin_pct, any_tagged, revenue_by_account, expenses_by_account, revenue_lines, expenses_lines}, ProjectFigures::{months_net_to_date, period_margin_pct, period_lines} and contribution_margin_pct, which books.project and books.projects now return too (margin_pct, to_date.by_account, by_month[].net_to_date). No mutation run (P12, D-33; none on the GUI); each test below was checked by breaking what it guards and watching it fail.

• ledger-core: tests/spec_projects.rs contribution_margin_is_one_place_and_none_without_revenue (64.0, 100.0, -150.0, half to even at 1.25 and 1.35, none at zero or negative revenue, none, not a panic, on overflow), months_net_to_date_runs_from_before_the_months (opens on last year's deposit; a reimbursement above its cost leaves the expense below zero; no entries: every month zero, no margin), a_reversal_nets_a_project_to_zero (no account left, two lines counted: tagged, breaking even; a period before both counts none) and closing_entries_are_left_out_of_project_figures (a close's lines aren't counted); properties.rs prop_project_contribution_is_the_net_to_date (random tags, sides, refunds and reimbursements over two expense accounts and a random period: the accounts sum to the totals, the contribution is revenue less expenses, each month's net to date is project_to_date through its end and the last is the net to date, the counted lines are the tagged revenue and expense lines to date and in the period, a margin exists exactly when revenue is above zero and has the contribution's sign, and project_figures' to-date is project_to_date's). project_figures takes the net before its first month from to date less the months (one scan fewer); the proptest pins it.
• ledger-mcp: tests/spec_projects.rs project_snapshot_margin_by_account_and_running_net (the period's and to date's margin_pct, to_date.by_account, the 12 months' net_to_date opening on the December deposit and ending on to_date.net, a loss's negative margin, null without revenue, a project with nothing tagged still carrying to_date.by_account: [], and books.projects carrying the margin but not the accounts). books.project's description stays under 700 characters (tool_descriptions_fit_700_characters).
• viewer and server on one book: ledger-cli tests/projects_parity.rs a_projects_snapshot_is_the_same_in_the_viewer_and_from_the_server (wanderbooks dev-stdio's books.project against the viewer's page_figures and Snap on the same books: to date's revenue, expenses, net, margin_pct, unrecovered cost and by_account, every month's figures and net_to_date over the chart's span, and the fiscal year's; with a refund, a reversal and overhead; gui builds only).
• ledger-gui: tests/projects.rs a_profitable_projects_snapshot_is_ledger_cores (and the Contribution tile's hover note is CONTRIBUTION_NOTE), a_loss_making_project_is_in_the_red (costs largest first: the higher-coded account is the larger), an_on_spec_projects_snapshot_has_its_unrecovered_cost (each tile's own value, read under its label, equal to Snap::to_date of project_to_date, the pill, the margin shown only with revenue, overhead never counted), no_revenue_means_no_margin, a_project_with_no_entries_has_nothing_tagged_yet, a_cost_repaid_exactly_breaks_even (no account left: break-even, not "nothing tagged", on the page and the list), a_reimbursement_above_its_cost_leaves_costs_below_zero, a_project_started_this_month_charts_one_month, the_chart_runs_from_the_start_or_first_entry_and_caps (the earlier of start and first entry, a start after today, 24 months at most), the_running_net_is_each_months_net_to_date (sweeping the pointer over the bars and over the net's own strip shows each month's months_net_to_date, in order), the_fiscal_year_switch_shows_the_default_period (B-30's omitted dates, as books.project, with fiscal-year costs unlike to date's; the pill stays to date; switching writes nothing to the journal), a_fiscal_year_with_nothing_says_so, the_list_cues_in_the_black_and_in_the_red (each net painted in its cue's color, never the names', still alphabetical), and the proptest prop_snapshot_contribution_is_the_net_to_date (reversals too: a reversed tagged line is tagged and breaks even); the earlier tests take the new labels (Revenue, Contribution, Contribution margin). With SHOT_DIR set each snapshot case is saved as a PNG; run them one at a time then (SHOT_DIR=... cargo test -p ledger-gui --test projects -- --test-threads 1: rendering from tests run in parallel crashed with SIGSEGV, 2026-10-22; without SHOT_DIR nothing renders and they run side by side). screens.rs gains project-templates (the demo's profitable project). Shots: ~/.cache/wanderbooks/shots-p3-snapshot/ (light/, dark/, w900/, tests/).
• Every test honors TMPDIR. .cargo/config.toml forced [env] TMPDIR = "/tmp" for every cargo-run test (for just mutants*' speed), so a TMPDIR set to keep tests off a small RAM /tmp was overridden; it is gone. Every test makes its dirs with std::env::temp_dir() or tempfile (both TMPDIR), and the binaries tests spawn with a cleared environment write no temp files. A socket under a long TMPDIR is longer than a socket address holds: every test connects through ledger_store::root::SocketPath, as the servers bind (raw_admin in local_server.rs didn't, and failed with TMPDIR under ~/.cache/wanderbooks/p3-snapshot-tmp). ledger-gui's exports.rs downloads folder, shared by its tests, is removed as the binary exits (atexit; wb-*, so sweep-test-tmp catches a killed run). Checked by running just check with TMPDIR under ~/.cache/wanderbooks and finding no new test dir in /tmp. Mutation runs (just mutants*) now put test books under that TMPDIR too, on disk: slower per mutant than /tmp was; none is running (P12 paused).

For P12 (mutation targets): contribution_margin_pct's <= and rounding strategy; project_figures' opening net and running sum; profit_and_loss_counted's counts; Standing::of's order.

Invoices and bills take a project (2026-10-22)

rules.md B-37 item 8: each invoice and bill line takes an optional project (books.create_invoice / books.create_bill class); the entry's revenue or expense side is one line per project (arap::document_parts), the receivable or payable and the payments untagged; journaled as the line's class_id behind the new feature document_line_projects (B-27).

• ledger-core: tests/spec_document_projects.rs (an_invoices_revenue_is_one_line_per_project_and_the_receivable_none, a_bills_cost_is_one_line_per_project_and_the_payable_none, an_untagged_document_posts_as_before, a_line_naming_an_unknown_project_is_refused_whole, a_finished_project_still_takes_an_invoice, tags_move_only_the_project_figures (twin books, tagged and not: the P&L, the 1099 worksheet and a party's activity identical; the projects with the untagged lines partition the P&L), document_parts_refuse_past_exact_arithmetic, reversing_a_tagged_document_takes_its_projects_to_zero (a partial payment moves no project figure; the reversal carries each line's project, so every project nets to zero), and the proptest prop_document_parts_partition_the_total); bookspec projects-invoice-and-bill-lines-count-by-project (the loader gains an invoice event and a document's lines with project; loader tests a_document_line_naming_an_unknown_project_is_refused, a_document_with_an_amount_and_lines_is_refused, an_invoice_lines_project_is_what_the_project_counts).
• ledger-store: tests/document_projects.rs (a_tagged_invoice_journals_each_projects_line_and_replays: the exact lines, then verify, reopen and the viewer's snapshot; a_tagged_bill_tags_its_expense_lines_never_the_payable; an_untagged_document_journals_as_before: no class_id anywhere; a_document_naming_a_project_waits_for_the_feature: books with projects but not this feature refuse, journaling nothing, not even the control accounts; old_invoices_and_bills_replay_unchanged: an earlier version's journal opens, verifies, writes nothing; a_document_lines_class_id_that_isnt_an_id_is_corrupt; a_reversed_tagged_invoice_replays_with_its_projects_at_zero: one entry.reversed, its replay tagged as live); format.rs document_line_projects_is_its_own_feature.
• ledger-mcp: tests/spec_projects.rs (invoice_and_bill_lines_count_toward_their_projects: by name, id and any capitals; books.get_entry's line project and class_id; payments untagged; books.project, profit_and_loss_by_class, vendor_1099 and books.party totals; a_document_naming_an_unknown_project_is_refused_whole, a_document_for_a_finished_project_says_so, an_invoice_for_an_on_spec_project_asks_about_an_agreement (an invoice's note, a bill's none), books_without_the_feature_refuse_a_tagged_document with the handbook's text both ways, by books.handbook and as the books://handbook/projects resource); handbook.rs document_projects_follow_the_books_feature (no sentence lets a shared cost be split on a document; the allocation convention only when books.conventions has one).
• ledger-gui: tests/projects.rs (an_invoice_and_a_bill_show_each_lines_project: each document line's project a link that opens it, untagged lines bare; the_demos_client_work_counts_every_client_invoice); pages::entry::tests::a_tagged_line_keeps_its_amounts_in_their_column (in a narrow pane a tagged line's name is cut to leave its tag room: looking at the demo's invoice page at 1,100 points found the tag pushing the credit column past the pane, a fault every tagged entry had); tests/screens.rs shoots an invoice's and a bill's page.
• ledger-cli: tests/projects_parity.rs (invoiced_and_billed_project_figures_are_the_same_in_the_viewer_and_from_the_server: made through the server's tools, read by both, the month lists the same length and not empty); tests/format_upgrade.rs books_p2_served_cut_over_whole refuses a tagged invoice and bill before consent and takes them after.
• fuzz: fuzz_store_replay can now declare features (this one among them), so a document line's class_id reaches replay under a declared format.

Broken to confirm (each restored): the core's revenue/expense line left untagged (core 4 and store 3 tests fail); document_parts one part per line (4 core, the proptest among them); the store's feature check dropped (store gate test, MCP books_without_the_feature_..., CLI books_p2_served_cut_over_whole); document_line_json without class_id (3 store); parse_document_lines ignoring it (4 store, the corrupt-id test among them); the entry.line_class_set not journaled (3 store, by verify); the MCP ignoring a line's class (4 MCP); no late-tag notes (1 MCP); the handbook ungated (the handbook unit test and 1 MCP); the handbook's rule without the owner's decision of D-43 (one project or none a line, no percentage, a shared cost by the allocation convention: the handbook unit test); books.get_entry without project (2 MCP, the CLI parity test); the viewer's document lines dropped, or their project not a link (the GUI tests); no room kept back for the tag (the narrow-pane test); the demo's invoices untagged (the demo test); the bookspec loader dropping a line's project (every_bookspec_example_holds). After review: the projects handbook's old "split a shared cost across lines" sentence restored, or the convention made unconditional (the handbook unit test); no on-spec note, or one on a bill too (the on-spec MCP test); the handbook resource served as if the feature were declared (books_without_the_feature_...); books.get_entry's class_id dropped (invoice_and_bill_lines_...); the server's months cut short (the parity test, which zip alone let pass); a reversal's line tags dropped (the core and store reversal tests); the bookspec's Harbor made on spec again (every_bookspec_example_holds). A separate up-front unknown-class check in the core was removed: equivalent to set_line_class's own refusal inside atomically.

For P12 (mutation targets): document_parts (the first-appearance order, the contains test); add_document_parts' tag index; ensure_document_lines' any; document_line_json's if let; parse_document_lines' arms (null, absent, out of u32); document_notes' dedup and its invoice flag; on_spec_invoice_note's kind test; document_projects_rule's branch; the viewer's document_of (invoice before bill).

After P3: the cutover review's open points 1 and 2 (2026-10-22)

The P3 cutover review's open points 1 (the IIF left CLASS empty) and 2 (a state filing fee read as cash paid to suppliers). Point 3 (ties in the tax-basis member split) waits for the owner: nothing is posted before the year-end close. No mutation run (D-33).

Point 1, the IIF's classes (rules.md B-34 rule 8): ledger-import tests/spec_import.rs iif_writes_each_lines_class_and_declares_the_classes_first (the file exact: the !CLASS list after the accounts, before !TRNS, every class declared, each line's class in CLASS, empty where it has none; no list without classes), iif_class_names_fit_quickbooks_and_every_change_is_listed (a colon and an accent, a name past 31 characters, two alike once cut, two alike ignoring case, one another's tagged form, a padded name: each written form exact, every change listed and said), iif_class_names_written_as_the_books_have_them_are_kept (review of the follow-ups, finding 4: "Café" beside "Cafe" and "Cafe (1)" is tagged twice and the two own names kept; own names alike, or changed names alike, each tagged once; with "Cafe (1) (1)" too, tagged a third time; a name a tag can't change, cut and ending in its own id, stands and the own name it meets is tagged), iif_refuses_an_undeclared_or_unfit_class, and the property iif_class_names_never_clash (256 cases of random and clashing names, old books' duplicates included, "Café" and its twins among them; a name written as the books have it, no other own name alike, is kept); check_iif now takes CLASS lines and check_iif_classes checks every TRNS and SPL line's class. ledger-package tests/package.rs the_package_iif_carries_each_lines_project (the package's file, warnings and README) and the bookspec example iif-quickbooks-journal-file.toml, now with two projects (one carried, one only declared). Broken to confirm: writing CLASS empty again fails the two exact-file tests, the package test and the bookspec example; dropping the " (id)" tag fails the names test and the property; tagging every name that meets (no yielding) fails the kept-names test and the property. The property found (seed in spec_import.proptest-regressions) that a cap of two tags made an own name yield to a changed one ("Café" twice beside "Cafe (1)" and "Cafe (1) (1)"); the cap is gone, a tag that changes nothing is skipped instead.

Benchmarks (baseline 2026-10-13)

No budget, by decision (the owner, 2026-10-13: the books do little work and are fast enough). The numbers are a baseline to spot a regression.

40-account chart, two-line entries across a year, on the development laptop:

	1k entries	10k entries
clone the ledger (store rehearsal, per command)	56 µs	1.0 ms
post one more entry	1.0 µs	5.8 µs
trial balance	44 µs	1.07 ms
balance sheet	47 µs	1.04 ms
one month's P&L	25 µs	248 µs

The store, 10k two-line entries on the laptop's disk (every journal append is synced; benches/store.rs in ledger-store):

	10k entries
open the books (verify the chain, replay, catch the database up)	249 ms
the viewer loading them	616 ms
a full verify (replay, projection, every table)	809 ms
post one entry (create, two lines, post: four synced appends)	62 ms

Formerly assumed: checked against the standards (2026-10-13)

The owner isn't an accountant and won't adjudicate these; each was checked against published sources instead (rank: FASB ASC via the Deloitte DART reproduction, SEC, IRS; then textbooks; software practice is evidence of convention only). Verdicts: CONFIRMED (a source supports it), CONVENTION (no standard governs; matches mainstream practice), DESIGN (not an accounting question), CHANGE (a source says otherwise; work pending).

#	Behavior	Verdict	Source / note
1	A P&L whose start is after its end is refused	DESIGN	No standard governs a reversed range; refusing beats silently swapping a typo
2	A balance sheet omits zero-balance accounts	CONFIRMED	Reg. S-X 210.4-03(a): "No caption should be shown ... as to which the items and conditions are not present." A comparative statement must still show a zero beside a non-zero prior column
3	The lifetime profit_and_loss counts closing entries	CONFIRMED	Used as earnings not yet closed on the balance sheet; closed income is already in capital (OpenStax Principles of Financial Accounting 5.1). Renamed unclosed_earnings (2026-10-14)
4	Closing a period with nothing to close still locks it	CONVENTION	A close is a lock (B-12); a dormant month must still lock and count for close-in-order
5	Draws and distributions are closed into capital at period end	CONFIRMED	OpenStax 5.1: dividends "are closed to the permanent account"; drawing accounts close to owner's capital. Monthly closes mean the year's K-1 Item L withdrawals sum across months
6	Reconciliation balances	CONFIRMED	Signed by the account's normal side (a card reads as owed), as statements show it; reconciling_a_card_reads_its_normal_side_...
7	A member's ending on one equity statement may differ by a cent from the next statement's beginning	CHANGED 2026-10-13; CHANGED P3	A capital account is one running balance (Treas. Reg. §1.704-1(b)(2)(iv)(b); the Item L quote this row once gave was misread, P3 review R-4). Undistributed earnings now split cumulatively as of each date, so each member's capital chains exactly (each_members_capital_chains_across_statements; it fails on the old code); since P3 the split is what the count's next close would give, so a date's capital never moves when its month is closed (D-38; each_members_capital_chains_and_holds_through_closes); rules.md B-13
8	Cash flow nets one line per account; investing comes only from registered assets	CHANGED 2026-10-13	ASC 230-10-45-7: gross receipts and payments "more relevant" than net; 45-8 limits netting to quick-turnover items. Financing and investing are now gross; loans made and investments bought are investing (230-10-20, 45-13) via [books] investing_accounts. Owner-advanced expenses: PwC 6.9.3.1 constructive treatment via [books] financing_accounts (rules.md B-14)
8a	Cash flow by the indirect method; member-paid expenses as constructive receipts	CHANGED 2026-10-20	The direct method with the reconciliation as a separate schedule (ASC 230-10-45-25, 45-30); noncash investing and financing activities disclosed, only the cash portion reported (50-3, 50-5). Member-paid expenses stay constructive receipts and disbursements, now gross and on each payment's date, and the same for a lender's payments and an expense paid into capital: a choice (D-42, after a day as noncash under D-35), since ASC 230 doesn't address payments made on the entity's behalf and the firm guides present them so (PwC 6.9.3.1, DART 7.2, BDO 3.4, EY 4.6.2; KPMG Q8.3.10 also accepts noncash for property a lender pays for). rules.md B-14 rule 11, P3 defect 1
9	An asset's life ends at purchase + life months, that day not held; day-count proration	CONVENTION	Exactly N months of service; day proration and the mid-month convention are both accepted book policies (ASC 360-10-35-4, read 2026-10-14: any systematic and rational allocation)
10	A payroll entry has one line per account total	CONFIRMED	The per-employee detail the IRS requires ("Amounts and dates of all wage ... payments", Employment Tax Recordkeeping) is kept in the run; a summary entry is standard
11	A period with exactly the dates of an existing one is allowed	DESIGN	Nothing governs duplicate periods; harmless (the second close locks only). Refusing exact duplicates is an option
12	Each close into members' capital rounds on its own (ties to the earlier member)	CHANGED 2026-10-13; CHANGED P3	Twelve monthly 50/50 closes could leave one member several cents ahead. A run of members closes split cumulatively from 2026-10-13 (Lean runPart_telescopes; property each_member_stays_within_a_cent_of_their_share fails on the per-close rule), but any other close restarted the run. Since P3 a count of members closes runs from the company's first close (D-10), skipping closes to anything else and ignoring the members' order, so no member is ever a cent from their share (the_audit_odd_cent_never_piles_up_across_closes fails on the run rule; Kani cumulative_close_never_drifts_a_unit_at_*, Lean allocW_cumulative_drift); journaled "cumulative_since", older closes replay as booked (rules.md B-13)

Questions are settled from the sources, not by any one company's CPA (wanderbooks is general software). Where the standards leave a real choice, it is a per-company setting with a sourced default, for that company's accountant to review: the cash flow account roles (rules.md B-14) are the first.

Gap list: what isn't covered, and what would bring it in

Technique	Status	Trigger
Fault injection	SKIP for the core (no I/O, clock, or network); DONE for the store's journal (full disk, cut-off append)	the first I/O or clock in ledger-core
Integration	SKIP for the core (no collaborators)	the core gains one; covered at the store and MCP layers
End-to-end	SKIP for the core (a library)	MCP stdio tests cover the journeys
Security properties	SKIP for the core (no roles, no secrets)	the first permission concept, or a secret-bearing field
Concurrency stress	SKIP for the core (no shared state); DONE for the store's writer + viewer (found the false "differs")	the first Arc, atomic, or lock in the core; the MCP server's HTTP transport shares one store across sessions (next)
Lean: apportion's sum law for any n	DONE (2026-10-14)	verify/lean/Wanderbooks/Apportion.lean: ranks are a permutation of 0..n-1 (strict total order + pigeonhole, core Lean only), so exactly u parts get a unit and one the fraction; apportion_sum and apportion_sum_of_shortfall, standard axioms only
ASC paragraphs not yet read	DONE (2026-10-14)	read in the ASC basic view (docs/spec/sources/fasb-asc.md): all confirm the rules; one citation fixed (230-10-45-14(b), not (2))
GnuCash's own close	OPEN	the oracle books closes as ordinary entries; comparing GnuCash's Close Book needs its Scheme API
Import: spec-blind suite, footing properties, mutation	DONE	sources vendored (Intuit bank CSV and IIF, ECMA-376/Excel numbers, IRS form lines); specs on every module; tests/spec_import.rs (spec-blind, footing and round-trip properties, XLSX read back from its XML, layout and styles); fuzz_import_csv; templates checked against the engine's control accounts; mutation one equivalent left
MCP, config, GUI crates	DONE (2026-10-14)	the same playbook: sourced module specs (config: Pub 538, Treas. Reg. 301.7701-3; MCP: the MCP tool spec and JSON-RPC 2.0); spec-blind suites spec_config.rs, spec_mcp.rs, spec_gui.rs; the MCP oracle oracle_mcp.rs (every export against ledger-core); startup, HTTP concurrency, and the viewer's read-only promise (read_only.rs) tested; fuzz_config_parse; mutation above