P3: assets' posted and scheduled depreciation, their bases, and the K-1 on the tax basis (defect 13, D-41)

Book value is cost less what the books posted; the schedule's figure is
apart. An asset's acquired date comes from its entry. Contributed
property keeps its section 723 carryover basis apart from its depreciable
basis (the lower of value and adjusted basis), with its 704(c) built-in
gain and method. The K-1 worksheet reports tax-basis capital (Form 1065
Item L) beside the book figures, leaving open what only the CPA knows.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

docs/mcp-interface.md

@@ -595,11 +595,23 @@ the lifetime total is exactly (cost − salvage), rounded to the currency's
 minor unit. A new asset's cost and salvage are in the minor unit, and its
 life's last day is 9999-12-31 at the latest.
 
-- `books.register_asset { description, purchase_date, cost, salvage_value?,
-  useful_life_months, cost_account, accum_depr_account, expense_account,
-  tag?, serial? }` → `{ asset_id, tag }`. Accounts resolved by id or code.
-  Without `tag`, the next free `PREFIX-0001` (`[books] asset_tag_prefix`,
-  else the company name's initials without LLC/Inc; "FA" when none).
+- `books.register_asset { description, in_service_date, cost,
+  salvage_value?, useful_life_months, cost_account, accum_depr_account,
+  expense_account, tag?, serial?, acquisition_entry?, basis_rule?,
+  contributor_adjusted_basis?, fmv_at_contribution?, sec704c_method?,
+  basis_source? }` → `{ asset_id, tag, in_service_date, acquired_date,
+  basis?, notes? }`. Accounts resolved by id or code. Without `tag`, the
+  next free `PREFIX-0001` (`[books] asset_tag_prefix`, else the company
+  name's initials without LLC/Inc; "FA" when none). `in_service_date` (the
+  day it is ready and available for its use) starts depreciation (P3,
+  defect 13; B-15); `purchase_date` is its alias for one release (both
+  given and different: refused; the alias noted in `notes`). The
+  `acquisition_entry` (posted, debiting the cost account, dated on or
+  before the in-service date) gives `acquired_date`, which puts the asset
+  on the register; with none, the acquired date is the in-service date.
+  The basis facts are `books.set_asset_tax_basis`'s (`tax_basis_rule` and
+  `contributor_basis`, with the old rule names, are aliases for one
+  release); a bad one registers nothing.
 - `books.label_asset { asset, tag?, serial?, clear_serial? }` → `{ asset_id,
   tag, serial }`: set or change the tag (unique ignoring case, never reused
   by another asset even after a retag or disposal) or the manufacturer's
@@ -614,11 +626,55 @@ life's last day is 9999-12-31 at the latest.
   a disposed asset's ends on its disposal day. A schedule an earlier
   version's asset can't compute is a tool error saying why, never a
   panic.
-- `books.list_assets {}` → assets with status, accumulated depreciation
-  by schedule and book value as of today (a disposed asset's through its
-  disposal day); `accumulated` and `book_value` are null, with
-  `schedule_error` saying why, for an asset whose schedule can't be
-  computed (one bad asset never fails the list).
+- `books.list_assets { as_of? }` → `{ as_of, assets }` (default today, the
+  company's time zone): per asset `in_service_date`, `acquired_date`,
+  `cost`, `status`, `held` (acquired by `as_of` and not disposed),
+  `accumulated_posted` (what the books carry: its depreciation runs, less
+  reversals, a reversal of a reversal reinstating),
+  `accumulated_scheduled_through` (what the schedule says is due by
+  `as_of`), `unposted_depreciation` (the difference: run
+  `books.run_depreciation`), `book_value` (cost less posted: what the
+  books carry), and `basis` (as `books.set_asset_tax_basis` reports it).
+  Disposed by `as_of`: every figure 0.00; acquired after `as_of`: the
+  figures null. The rows are the register's (`fixed_asset_register`). An
+  asset whose figures can't be computed (one an earlier version took)
+  lists with them null and `schedule_error` saying why: one bad asset
+  never fails the list.
+  Before P3, `accumulated` was the schedule's figure and `book_value`
+  cost less it.
+- `books.set_asset_tax_basis { asset, rule, contributor_adjusted_basis?,
+  fmv_at_contribution?, sec704c_method?, basis_source? }` → `{ asset_id, basis:
+  { rule, contributor_adjusted_basis, fmv_at_contribution, fmv_recorded,
+  tax_basis_723, depreciable_basis, built_in_gain_704c, sec704c_1c_note?,
+  sec704c_method, source?, sources }, notes? }`. `rule`: `purchase` (the
+  company bought it: depreciable basis is its cost, IRC §1012),
+  `carryover_723` (a member contributed business property: the company's
+  §723 basis is the member's adjusted basis, depreciated from), or
+  `personal_use_conversion` (a member contributed personal-use property:
+  the §723 basis as for carryover, depreciable basis the lesser of fair
+  market value and that basis, Treas. Reg. §1.168(i)-4(b); D-41). A
+  contribution needs `contributor_adjusted_basis` (cost plus improvements,
+  less depreciation allowed or allowable, IRC §1016(a)) and
+  `fmv_at_contribution` (a fact the human gives: never assumed from the
+  cost); `built_in_gain_704c` = value − §723 basis at contribution (Treas.
+  Reg. §1.704-3(a)(3)(ii)), with the IRC §704(c)(1)(C) note when it is a
+  loss. `sec704c_method`: `traditional`, `traditional_with_curative`,
+  `remedial` (Treas. Reg. §1.704-3(b)-(d)). `basis_source` `{ decided_by,
+  decided_on?, citation?, note? }`: who gave the facts. `sources` names
+  each figure's authority. The figures are at contribution or purchase;
+  tax depreciation and what remains of a built-in gain later are the
+  CPA's. The old names (`cost`, `carryover`, `contributor_basis`) are
+  aliases for one release, noted. Journaled as `asset.basis_set` (the
+  journal feature `asset_basis`: books an older version wrote refuse it,
+  `format_upgrade_pending`, until the owner's format upgrade); a record
+  written before P3 (`asset.tax_basis_set`) reads its value as the book
+  cost (`fmv_recorded: false`).
+- `books.correct_asset { asset, cost?, salvage_value?, useful_life_months?,
+  in_service_date?, reason }` → `{ asset_id, tag, cost, salvage_value,
+  useful_life_months, in_service_date, acquired_date, basis, notes? }`.
+  Refused while the books carry depreciation for it (a run posted and not
+  reversed), and for an in-service date before its acquisition entry's
+  date; `in_service` is the alias of `in_service_date` for one release.
 - `books.run_depreciation { period: "YYYY-MM", asset_id? }`
   → `runs: [{ asset_id, description, period, amount, caught_up, entry_id,
   already_posted }]` and `skipped: [{ asset_id, description, reason }]`.
@@ -635,7 +691,8 @@ life's last day is 9999-12-31 at the latest.
   run-all's assets not yet in service and any whose schedule can't be
   computed. A run before the in-service date is refused.
 - `books.dispose_asset { asset_id | tag, date, proceeds, proceeds_account,
-  gain_loss_account, buyer?, confirmed?, receipt_attachment_ids? }` →
+  gain_loss_account, buyer?, confirmed?, receipt_attachment_ids? }` (the
+  date never before the acquired date) →
   without confirmation: `{ status: "preview", accumulated, book_value,
   proceeds, gain_loss, final_depreciation, excess_depreciation,
   catch_up_depreciation, lines, receipt_required }` and posts nothing;
@@ -658,12 +715,23 @@ life's last day is 9999-12-31 at the latest.
   posts (`party_required`); a retirement with no proceeds and no buyer is
   marked as having no counterparty.
 - `books.export { report: "fixed_asset_register", format: json | csv,
-  as_of? }`: every asset registered by the date (tag, serial, cost,
-  depreciation by schedule, book value, disposal), totals, and the
-  general ledger's balances of the assets' cost and accumulated
-  depreciation accounts, with `unposted_depreciation` and
-  `unregistered_cost` (zero when register and books agree;
-  `ledger_core::fixed_asset_register`).
+  as_of? }`: every asset acquired by the date (tag, serial, acquired and
+  in-service dates, cost, accumulated depreciation scheduled and posted,
+  book value as cost less posted, disposal, the basis facts and figures:
+  rule, contributor's adjusted basis, value at contribution and whether
+  it was recorded, §723 basis, depreciable basis, §704(c) built-in gain,
+  method, who gave the facts), totals (`total_accumulated_scheduled`,
+  `total_accumulated_posted`, `total_book_value`, `total_tax_basis_723`,
+  `total_depreciable_basis`, `missing_basis`), and the general ledger's
+  balances of the assets' cost and accumulated depreciation accounts, with
+  `unposted_depreciation` (scheduled less books), `unattributed_accumulated`
+  (books less the runs: an entry made by hand) and `unregistered_cost`
+  (zero when register and books agree; `ledger_core::fixed_asset_register`).
+  CSV columns: `tag, description, serial, acquired, in_service, cost,
+  salvage, useful_life_months, accumulated_scheduled, accumulated_posted,
+  book_value, status, proceeds, basis_rule, contributor_adjusted_basis,
+  fmv_at_contribution, fmv_recorded, tax_basis_723, depreciable_basis,
+  built_in_gain_704c, sec704c_method, basis_source`, then a TOTAL row.
 - `books.show { asset }` opens an asset in the viewer; `page: "assets"`
   and `report: "fixed_asset_register"` open the register.
 
@@ -1918,7 +1986,20 @@ entries.
   year cancel: neither is a contribution or a distribution. A member's
   party is the party with the member's name (not a display name) and the
   member role, as the viewer's capital statement finds it; with none, the
-  member's TIN is a gap.
+  member's TIN is a gap. **Tax-basis capital** (`k1-tax-basis-capital.csv`,
+  P3, D-41, rules.md B-36; Form 1065 instructions, Item L, the tax-basis
+  method): per member, `member, item, book, tax_basis, book_less_tax,
+  status, note` for each Item L line (beginning; capital contributed,
+  cash and property; current year net income (loss); other increase
+  (decrease); withdrawals and distributions; ending), the property at its
+  §723 basis (`ledger_core::tax_capital`), then the reconciliation of book
+  to tax capital by cause (the §704(c) built-in gain or loss share,
+  property without a tax basis in the books, property distributed). A
+  line the books can't know (tax depreciation of the fixed assets in
+  service, a disposal's tax gain, the basis of property distributed or of
+  contributed property no asset holds) has `tax_basis` blank, status
+  `open: the CPA's`, and a note with what the books know so far and the
+  book amount the CPA's figure replaces; never a guessed number.
   **1099 worksheet** (`1099-worksheet-<year>.csv`, `as_of`'s calendar
   year) is `books.vendor_1099`'s CSV (above) for the package's cash and
   financing accounts: the payments from January 1 through `as_of` (the