FactLot

Build a base-rent schedule from commencement date, term, area, starting $/SF/yr, escalations (percent or fixed $/SF), and abated months. Lease months run from the commencement day-of-month with no calendar proration (warns when commencement is mid-month). Returns rent steps, totals, expiration date, and a calculation trace. Optional unit (kw, mw, unit, acre, key, room, space) relabels area and $/SF for data-center, ground, yard, residential, hotel, or parking leases without changing any number. Deterministic: use this instead of doing the math yourself; cite formula calc.rent_schedule@1 and the returned steps, and surface any warnings.

Compute effective rent, straight-line net effective rent, and discounted net effective rent ($/SF/yr) after free rent, TI allowance, leasing commissions, and other landlord concessions. Rent is monthly in advance from the commencement day (no calendar proration), discounted at annual rate ÷ 12. schedule.unit (kw, mw, unit, acre, key, room, space) reports $/kW/yr, $/acre/yr and so on instead of $/SF/yr. Deterministic: use this instead of doing the math yourself; cite formula calc.net_effective_rent@1 and the returned steps, and surface any warnings.

Rank 2–20 lease proposals with different terms, sizes, free rent, TI, concessions, and operating-expense structures (gross, NNN, base year, expense stop, with opex growth) on one discounted $/SF/yr basis, per rentable or usable SF (load factor): effective occupancy cost (tenant perspective) or discounted net effective rent after landlord-borne opex and optional pre-commencement downtime (landlord perspective). Cash flows monthly in advance at annual rate ÷ 12; warns when the usable-SF ranking differs and when terms differ. schedule.unit (kw, mw, unit, acre, key, room, space, the same for every proposal) ranks per kW, MW, unit, acre, key, room, or space instead of per SF. Deterministic: use this instead of doing the math yourself; cite formula calc.compare_proposals@2 and the returned steps, and surface any warnings.

Analyze an apartment rent roll (up to 5,000 units with status occupied, notice, vacant, model, or down; market and lease rent per month; lease dates; concessions as weeks free, months free, or dollars): gross potential rent, vacancy, non-revenue units, loss to lease, concessions amortised straight-line over each lease term, effective rent income, physical and economic occupancy, effective rent per unit and per SF, a lease expiration schedule by month, and a per-unit-type summary. Single-lease mode (lease instead of units) returns the effective monthly rent after a weeks-free or months-free concession. Deterministic: use this instead of doing the math yourself; cite formula calc.multifamily_rent_roll@1 and the returned steps, and surface any warnings.

Percentage (overage) rent for a lease year: net sales after exclusions over a natural or fixed breakpoint, prorated for partial years, less amounts already paid. Deterministic: use this instead of doing the math yourself; cite formula calc.percentage_rent@1 and the returned steps, and surface any warnings.

Reconcile a tenant's annual CAM charge: exclusions, occupancy gross-up of variable expenses, pro rata share, controllable-expense caps (compounding_from_base, simple_from_base, year_over_year), an admin fee (before or after the cap, inside or outside it, with per-line exclusions), base year or expense stop, partial-year occupancy (move-in/move-out prorates share, cap, and base by days), and estimates paid. Returns balance due and a full trace with order-of-operations warnings. Deterministic: use this instead of doing the math yourself; cite formula calc.cam_reconciliation@2 and the returned steps, and surface any warnings.

Reconcile CAM for a whole building in one call: the expense pool and gross-up once, then up to 500 tenants each with share, base year or expense stop, cap, admin fee, occupancy, estimates paid, and lease-specific excluded categories. Returns each tenant's statement (identical to calc_cam_reconciliation for that tenant, with its trace and warnings) and a building reconciliation: total billed against the recoverable pool, the unrecovered amount, and why (unleased or vacant share, lease exclusions, gross-up, caps, base years and stops, admin fees, zero floor, rounding). Deterministic: use this instead of doing the math yourself; cite formula calc.cam_reconciliation_batch@1 and the returned steps, and surface any warnings.

Recoverable capital expenditure under a lease clause: amortize a capital cost over its useful life or the lease-specified period, straight-line (declining interest) or level payment, with interest on the unamortized balance or none; optionally cap each year's recovery at demonstrated cost savings (with or without carry-forward); and allocate each year to tenants by pro rata share. Every assumption is echoed with an optional lease clause citation. Deterministic: use this instead of doing the math yourself; cite formula calc.capex_recovery@1 and the returned steps, and surface any warnings.

Size the maximum loan under any combination of max LTV, min DSCR, and min debt yield for a given NOI, rate, and amortization. Reports the binding constraint, debt service, and resulting metrics; optionally a stress table over NOI, rate, and value shocks (max loan, binding constraint, LTV, DSCR, debt yield per scenario) and the refinance shortfall against an existing loan balance. Deterministic: use this instead of doing the math yourself; cite formula calc.debt_sizing@3 and the returned steps, and surface any warnings.

Remeasure a lessee's lease liability and right-of-use asset under ASC 842 after a modification, lease-term reassessment, contingency resolution, or residual value guarantee change: new liability (PV of remaining payments), liability and ROU adjustments with any gain (ASC 842-20-35-4), and the per-period amortization table (operating: straight-line single lease cost; finance: interest plus amortization) in cents that foots: every row rolls forward exactly, totals are the row sums, and the final period trues up liability and ROU asset to zero. Warns where judgment is needed. Deterministic: use this instead of doing the math yourself; cite formula calc.lease_remeasurement_asc842@2 and the returned steps, and surface any warnings.

Prepayment premium, total payoff, and cost as a share of balance for a fixed-rate amortizing or interest-only loan under yield maintenance (PV of remaining payments or rate differential, with a minimum and an explicit discounting convention), a step-down schedule, a flat percentage, or defeasance (cost of the securities portfolio that funds the remaining payments plus stated costs). Deterministic: use this instead of doing the math yourself; cite formula calc.prepayment_and_defeasance@1 and the returned steps, and surface any warnings.

Weighted average remaining lease term in years as of a date (actual days ÷ 365.25), weighted by each lease's area_sf (weight_by "area") or annual_rent (weight_by "rent"). Deterministic: use this instead of doing the math yourself; cite formula calc.walt@1 and the returned steps, and surface any warnings.

NPV of periodic cash flows (t = 0, 1, 2, ...; the t = 0 flow is not discounted) at a per-period discount rate given as a decimal. Deterministic: use this instead of doing the math yourself; cite formula calc.npv@1 and the returned steps, and surface any warnings.

Periodic and annualized IRR of periodic cash flows, as decimals (0.085 = 8.5%), solved deterministically by scanning a 1-point grid of per-period rates and bisecting each sign change; reports every root it finds when cash flows have multiple IRRs (two roots within one grid step can be missed). Errors when the flows do not change sign or no root lies between -99.99% and 1000% per period. Deterministic: use this instead of doing the math yourself; cite formula calc.irr@2 and the returned steps, and surface any warnings.

Compare leasing with buying over a fixed horizon: NPV of each case's annual cash costs (rent, free rent, tenant expenses, and move-in costs versus equity, debt service, owner expenses, reserves, and a sale at the horizon by stated value or exit cap rate), optionally after tax, with the year-by-year tables and the break-even residual value at which owning equals leasing. Deterministic: use this instead of doing the math yourself; cite formula calc.lease_vs_own@2 and the returned steps, and surface any warnings.

Compare renewing in place with moving over one horizon: NPV and discounted effective rent of each case (rent schedule with free rent, TI net of allowance, fees, moving, downtime, double rent, termination, and disruption costs), the starting rent at which they break even, and year-by-year cash flows. Deterministic: use this instead of doing the math yourself; cite formula calc.renew_vs_relocate@2 and the returned steps, and surface any warnings.

Occupancy, ADR, RevPAR, TRevPAR, and a USALI-style profit ladder for a period: departmental profit, GOP and margin, GOPPAR, management fees, EBITDA, FF&E reserve, and NOI (EBITDA less replacement reserve). Deterministic: use this instead of doing the math yourself; cite formula calc.hotel_metrics@1 and the returned steps, and surface any warnings.

Property-level discounted cash flow from an in-place rent roll: each lease's rent, escalations, remaining term, and expense recovery (NNN, gross, base year), then at expiration one blended lease weighted by the renewal probability (renewal vs new-tenant rent, free rent, TI, leasing commissions, and new-tenant downtime, with fractional downtime and free rent kept as part months rather than rounded); market rent growth, general vacancy and credit loss, operating expenses, management fee, and capital reserves. Returns the annual cash-flow table (NOI and cash flow before debt) for the hold plus one year, the exit value at a cap rate on forward (or trailing) NOI less selling costs, the value (PV at the discount rate, end-of-year or mid-year), and with a purchase price the NPV, unlevered IRR, and equity multiple, with every lease event and convention stated. Deterministic: use this instead of doing the math yourself; cite formula calc.dcf_pro_forma@2 and the returned steps, and surface any warnings.

Value by direct capitalization: (NOI − capital reserve) ÷ cap rate, then below-the-line deductions for lease-up costs, free-rent burn-off, and other adjustments to an as-is value (optionally rounded); and the cap rate a price implies, before and after reserves and all-in after the below-the-line costs. Records the NOI basis (trailing, forward, stabilized). Deterministic: use this instead of doing the math yourself; cite formula calc.direct_cap@1 and the returned steps, and surface any warnings.

Period-by-period schedule of a fixed-rate loan, monthly or quarterly: an optional interest-only period, then level payments on an amortization term that can run past maturity (balloon), with 30/360, actual/360, or actual/365 interest (the payment on a 30/360 basis). Rows are in cents that foot: interest is rounded each period, the final payment repays the whole balance, and the totals are the row sums. Deterministic: use this instead of doing the math yourself; cite formula calc.amortization_schedule@1 and the returned steps, and surface any warnings.

Split periodic project equity cash flows between LP and GP: preferred return (compounding or simple) and return of capital pro rata to capital in either order, an optional GP catch-up, IRR-hurdle tiers with promote splits measured on the LP's IRR, and a residual split. Returns per-period LP and GP contributions and distributions (with the GP's promote) that foot to the cent, and LP, GP, and project IRRs and multiples, with the conventions to confirm against the operating agreement. Deterministic: use this instead of doing the math yourself; cite formula calc.equity_waterfall@1 and the returned steps, and surface any warnings.

Not tax advice: arithmetic only. The 45-day identification and 180-day exchange deadlines of IRC §1031(a)(3) (the exchange period ends earlier at a given tax-return due date), the three-property, 200%, and 95% identification tests of Treas. Reg. §1.1031(k)-1(c)(4), and the cash boot, mortgage boot, debt replacement, and trade-down of an exchange, with the boot-limited gain when the basis is given. Deterministic: use this instead of doing the math yourself; cite formula calc.exchange_1031@2 and the returned steps, and surface any warnings.

Dated list of a lease's notice deadlines and option windows, from its expiration date and options: each renewal option's notice deadline or notice window and renewal term (successive options count back from the term before), each termination option's last day to give notice, an expansion option deadline, and other deadlines (a stated date, or N days after a date such as a ROFO notice). Calendar months; N months before a date keeps the day of month, clamped to a shorter month's end (a warning gives the month-end reading when it is later). Deadlines on a weekend or US federal holiday (5 U.S.C. §6103, observed days included) are flagged, or rolled to the preceding or following business day when business_day_roll says so. With as_of: days to each event, passed deadlines warned, and the next deadline. Steps show each computation. Deterministic: use this instead of doing the math yourself; cite formula calc.critical_dates@1 and the returned steps, and surface any warnings.

Reconcile FactLot's DCF with another system's export (ARGUS or any other model; parity is not claimed and is untested against real ARGUS output): give the calc_dcf_pro_forma input plus the other system's annual lines {label, values: [year 1, …]}, optionally its value, unlevered IRR and sale price, a tolerance (absolute and relative) and your label mapping. Labels map to FactLot lines by your mapping, else by common CRE line names (Potential Base Rent, Absorption & Turnover Vacancy, Free Rent, Expense Reimbursements, General Vacancy, Credit Loss, Effective Gross Revenue, Operating Expenses, Net Operating Income, Tenant Improvements, Leasing Commissions, Capital Reserves, Cash Flow Before Debt Service); positive deductions are negated (sign_convention). Returns per line and year FactLot's amount, the other amount, the difference and whether it is within tolerance; unmapped labels; and for each differing line a likely_cause from FactLot's documented conventions, worded as a hypothesis to check: differences only in rollover years (fractional downtime and free rent), a rate on a different base (general vacancy), only the exit year, a one-year shift, management fee inside operating expenses, a growth rate, a constant factor or amount, rounding; and for the value FactLot rerun with mid-year or end-of-year discounting, the other exit NOI basis, or no selling costs. Deterministic: use this instead of doing the math yourself; cite formula calc.reconcile_dcf@1 and the returned steps, and surface any warnings.

Reconcile FactLot's CAM reconciliation for one expense pool with another system's per-tenant results (Yardi or any other; parity is not claimed and is untested against a real export): give the calc_cam_reconciliation_batch input plus, per tenant, what the other system reported (share, gross-up, cap limit and reduction, admin fee, base-year or stop deduction, billed amount, estimates, balance; billed_amount required) and a tolerance. Returns per tenant and line FactLot's amount, the other amount, the difference and whether it is within tolerance, tenants missing on either side, and likely causes worded as hypotheses to check: a different pro rata share (and, when every share differs by one factor, the pool's denominator), or a FactLot rerun that matches the other system with lines left to the default controllable: true set uncontrollable, the cap's base year one year off, the other cap method, the other gross-up target or no gross-up, the admin fee before or after and within or outside the cap, or no fee on uncontrollable lines; and differing estimates paid. Deterministic: use this instead of doing the math yourself; cite formula calc.reconcile_cam@1 and the returned steps, and surface any warnings.

Evidence calculation only: not an appraisal or an opinion of value, not legal or tax advice, and not a substitute for the advice of an attorney. The arithmetic of Tex. Tax Code §41.43(b)(3) and §42.26(a)(3), the subject's value against the median appraised value of a reasonable number of comparable properties appropriately adjusted. Takes 3–200 comparables chosen by the caller, each with its roll value and the caller's adjustments (percent, USD amount, or $/SF, each with a reason); optionally normalizes each comparable to value per SF of improvement or land area times the subject's area; applies percentages summed or compounded, then amounts; and returns every comparable's normalized and adjusted value, the sorted list, the median (for an even count, the mean of the two middle values), and the subject's value minus the median in USD (subject_minus_median) and as a fraction of the median (subject_minus_median_pct: 0.1554 means 15.54%, a decimal like every rate in FactLot, not 0.1554%), with the statutes cited. Warns on mixed value bases, §42.26(d) and the §23.231 limitation, comparables in another county, fewer than 5 comparables, total adjustments over 25%, and a comparable identical to the subject. It does not choose comparables, invent adjustments, or say whether to protest. Deterministic: use this instead of doing the math yourself; cite formula calc.tx_unequal_appraisal@1 and the returned steps, and surface any warnings.

Deadline to file a Texas property tax protest with the appraisal review board: the later of May 15 or 30 days after the notice of appraised value was delivered, rolled past weekends and Texas legal holidays, plus a conservative file-by date (the last business day on or before the unadjusted deadline). Returns the statute citations, the rule's verification status and a disclaimer. Information about a statutory deadline: not legal or tax advice and not a substitute for the advice of an attorney. Verification status: verified. Cite rule rules.tx.property_tax_protest_deadline@2 and its statutes.

Texas property tax protest deadlines for many notices in one call (1–200 items, e.g. a consultant's client list): each item's id, tax year and, if known, notice delivery date. Each result is exactly what rules_tx_property_tax_protest_deadline returns for that item under rule rules.tx.property_tax_protest_deadline@2 (deadline, unadjusted deadline, governing basis, conservative file-by date, skipped days, the item's warnings), echoed with its id; an item with invalid input carries its error and the others are still answered. summary counts the items per deadline, earliest first, with the earliest and latest deadline. The statute citations, the rule's verification status and the disclaimer appear once (value.rule, value.disclaimer). A rules tool: never a registry lookup. Information about statutory deadlines: not legal or tax advice and not a substitute for the advice of an attorney; it does not say whether to protest. Verification status: verified. Cite rule rules.tx.property_tax_protest_deadline_batch@1 and its statutes.

Deterministic FactLot ID for a parcel from state FIPS, county FIPS, and the assessor's parcel number (APN). The same parcel always yields the same ID, offline. Use it as the join key across systems. APNs that differ only in where a separator falls ("12-34", "1-234") get different IDs; in a county with a documented fixed-width format the variants of one APN converge (NYC BBL "3-1234-56" = "3012340056").

Deterministic FactLot ID for a legal entity (LLC, LP, corporation, trust) from its registry jurisdiction and file number, or from its LEI (an LEI whose ISO 17442 check digits do not match is rejected).

FactLot ID for a suite or unit within a building, given the building's FactLot URN (from id_building). Suite designators are normalized: "Suite 100", "Ste 100" and "#100" agree, while "1-20" and "120" stay distinct.

Deterministic FactLot ID for a building from its street address: county FIPS, ZIP code, and street line. Every condominium unit, suite, and floor at the address gets the same building ID, offline. Pass it to id_space for a suite, or to registry_get to see the building's parcels.

Content-addressed FactLot ID (SHA-256) for a document such as a lease, amendment, or estoppel.

Validate a FactLot URN and return its kind, components, and short ID.

Check one FactLot fact against the published fact schema (spec/schemas/fact.json): subject URN, dotted predicate, as_of date, provenance, optional rights; unknown fields are rejected at every level. Rules: every fact except a computed one cites at least one source (an inferred fact cites the evidence it was inferred from); a computed fact names its formula or cites a source; valid_from is not after valid_to; a source span does not end before it starts. For Ingest predicates (lease.expiration_date, lease.rentable_area_sf, lease.base_rent_schedule, ...) the value must have the predicate's shape and every source quote must state the value, by the same written-form rules as doc_verify_facts (a quote saying "2,500 square feet" does not support 1000). Not checked: that the quote is in the document, that the document or sha256 exists, that supersedes IDs exist, and quotes for other predicates; doc_verify_facts with the document's pages checks the quote. Returns { valid, issues }. Call before storing or sharing facts.

Check values YOU extracted from a document against its text, deterministically; FactLot runs no model. Send the pages as text and one candidate per value: {predicate, value, quote, page}. Each candidate is checked in order: (1) the value's shape (Ingest predicates such as lease.expiration_date YYYY-MM-DD, lease.pro_rata_share in (0, 1], ordered lease.base_rent_schedule steps; any other dotted predicate needs a non-empty value); (2) the quote, at least 12 characters, is on the cited page, where only whitespace, line breaks, letter case and typographic quotes and dashes may differ (a word hyphenated across a line must keep its hyphen; a quote found on exactly one other page is accepted with the page corrected); (3) every number, date and party name in the value is written in the quote, in any common form: 1250000 matches "$1,250,000.00", 0.03 matches "3%" or "three percent", 2031-06-30 matches "June 30, 2031" or "6/30/2031"; text the lease states as written (a prohibited use, a carve-out, a protected use) is written in it as words, ignoring case, punctuation and line breaks; (4) a confidence you give below 0.8 holds it for review; (5) every other part of the value must be confirmed by the quote too: a true/false value, an enum or a summary not written in the quote holds the candidate for review, named in the reason. Verified means every part of the value was found in the quote. Returns verified (FactLot facts: method extracted, citing document_id, page, quote and character span, plus which value parts were checked and as what), needs_review (the quote is on the page but does not state the value: check consistency; low confidence: confidence; a part FactLot cannot confirm from the quote, such as a boolean: coverage) and rejected (wrong shape; quote missing, too short, or on several pages), each with a reason to act on. Not checked: meaning (a quote stating the number in another context passes), and whether the pages came from the file whose sha256 you give.

Current-state lease abstract from a lease and its amendments, with amendment precedence, as of as_of. Give each document's pages with the candidates you extracted (checked exactly as doc_verify_facts checks them), or the facts doc_verify_facts already returned for it (without pages only the value against its quote is rechecked, marked quote_on_page: false). Documents may come in any order: give the lease role original and each amendment role amendment with its effective_date (without a role the lease is inferred only when that is unambiguous, otherwise it is an input error; two or more amendments need effective dates). The original applies first, then amendments by effective_date; a later document's value for a predicate controls, and the earlier one moves to history and is linked through supersedes. An amendment effective after as_of is pending: its values are listed under pending and pending_facts with a warning and do not control. A rent schedule restated from a later date keeps the earlier steps before it (carried_forward). Each field gives its value, the controlling document, page, quote and fact, the superseded history, conflicts (two different values from one document, or from two documents of the same rank), pending values and open_items (a candidate for that predicate in the controlling or a later document that needs review or was rejected, so the value may not be final). FactLot only orders what you extracted: it does not find terms you missed, and an amendment that changes a term without restating it ("extended by 24 months") needs the resulting value extracted with that sentence as its quote, which the quote check will hold for review if the date is not written there.

Compare values another document asserts (an estoppel, rent roll or offering memo, mapped by you to predicates) with verified lease facts from doc_abstract_lease or doc_verify_facts. Each asserted value comes back match, mismatch (with the differing fields), not_in_lease, or ambiguous_in_lease (two current lease facts disagree), with the controlling lease citation (document, page, quote). Values compare exactly as JSON: numbers by value, strings exactly (a name written differently is a mismatch), and for an object only the fields you assert. Facts another fact supersedes are ignored. When the lease fact is an extracted fact whose quote does not confirm part of its value (a true/false value, an enum), the result lists those parts in lease_not_checked. The lease facts must pass fact_validate; FactLot does not re-read the lease, so pass the facts its document tools returned.

Check one claim against a document page: {predicate, value} (anything doc_verify_facts accepts) or a short claim sentence ({text} or a bare string), plus the verbatim quote and page it rests on. Returns supported (the quote is on the page and every checked number, date and name in the claim is written in it), contradicted (the quote is on the page and states other numbers or dates of the same kind, listed in quote_states), or unverifiable (the quote is not on the page, nothing in the claim can be checked, or the quote states no value of that kind), with the evidence (document_id, page, quote, span) and each part checked. Textual, not semantic: for a sentence only its numbers and dates are compared, never its meaning, and a quote that mentions the right number for a different term still supports it.

Spread a T-12, operating statement, budget or rent roll summary YOU read, onto FactLot's published chart of accounts (multifamily, commercial, or hotel after the USALI summary), deterministically; FactLot runs no model. Send the pages as text and one line per item: {label, amount, quote, page}, optionally your category, a period column, and for a subtotal the indexes of the lines it sums; give the statement's own totals (effective_gross_income, total_operating_expenses, net_operating_income, ebitda, ...) as lines with that total as category. Each line is checked: the quote is on the page (a quote under 12 characters, such as a short row, only where it stands as whole words), the amount (as a number, any common written form; (1,200) and -1,200 read as negative) and the label are written in it; a line that fails is excluded with the reason, and a stated total that does not foot names the lines left out. The label is mapped to the chart by keywords: your category is used when it is in the chart, and an exception flags it for review when the dictionary maps the label elsewhere; an ambiguous or unknown label without a category is excluded. Vacancy, concessions, credit loss and other contra lines are always subtracted. Returns per period the sections, the computed totals (EGI, operating expenses, NOI, capital items, net cash flow; for hotels departmental profit, GOP, EBITDA and NOI after the replacement reserve), whether each total and subtotal the statement states foots (within 0.5 per line added, or your tolerance), every line with its citation (document, page, quote, span) and status, statistics (units, occupancy, ADR), and exceptions to review. Not checked: whether the agent missed lines, and meaning beyond the written amount and label.

Check a proposed use (a description, plus an optional use category or 2022 NAICS code) against a center's verified lease.exclusive_use and lease.prohibited_uses facts (from doc_verify_facts or doc_abstract_lease; each must pass fact_validate). Deterministic and textual: a restriction is a potential conflict when it shares a use category with the proposed use (FactLot's published use-category vocabulary, matched on keywords, the category given and NAICS codes) or shares words with it (two or more, or every significant word of the restriction). Each hit is labelled "potential conflict — needs human review" and returns the controlling quote and citation, the categories and words that matched, and the exclusive's carve-outs, flagging those that mention the proposed use. FactLot does not interpret the lease, decide whether a carve-out applies, or give legal conclusions; an empty result does not mean there is no conflict. Superseded facts are ignored.

Look up the lease predicates doc_verify_facts and doc_abstract_lease know (lease.expiration_date, lease.base_rent_schedule, lease.go_dark, ...) before extracting: for each, its value shape as JSON Schema, one valid example with a quote that states it (and whether that example verifies), which parts of the value are checked against the quote and how (number, ratio, date, verbatim name, as-written words, a worded enum, a number inside free text), which count as checked only when the quote writes them out (summaries, some enums), and which always need review (true/false values and enums no wording confirms, such as a CAM cap method or a kick-out party) unless a person confirms them. Generated from the same tables the checks use. Give predicate for one, prefix (e.g. lease.renewal) for a group, or neither for all. Also returns notes on statuses, paths, human confirmation and the generic rules for any other dotted predicate. Reads no document.

Bundle FactLot facts (each must pass fact_validate) into a fact package a counterparty can verify: canonical JSON (RFC 8785) of every fact, an RFC 6962 Merkle tree over the facts, the source documents the facts cite with their sha256 where known, and a digest over all of it. Returns the unsigned package, its digest, and signing_message, the exact text to sign. FactLot never holds private keys: to sign, the holder signs signing_message with their own Ed25519 key on their own machine (factlot.sign_fact_package in Python, signFactPackage in @factlot/tools, or fact_package_sign in the local MCP server). Deterministic: no clock time is added (pass created_at), and the same facts always give the same digest.

Verify a fact package from fact_package_create: recompute every fact's hash, the Merkle root and the digest from the content (any changed fact, title, date or document list shows as a mismatch); check each fact against fact_validate; check the Ed25519 signature, against the public_key you pass (base64url, the signer's key you trust) or, without one, only against the key inside the package (which proves nothing about who signed); and, given the source documents' pages, check every quote is on its cited page. Returns valid plus each check's details, checks_run and checks_not_run (what was and was not checked), and values_not_checked: the parts of extracted facts' values that their quotes do not confirm (a true/false value, an enum, a summary), which do not change valid. Not checked: that the pages you pass are the original files (pass sha256 to tie them to the file hash), or what the facts mean.

Check a lease comparable one firm shares with others, as a FactLot fact with predicate lease.comp, and derive its net effective rent. The fact goes through fact_validate (schema, citations, rights), then the comp's own rules: shape (spec/schemas/fact.json LeaseComp: area, commencement, term or expiration, starting or current rent, escalation, free rent, TI, leasing commissions, expense basis, confirming party, verification), an expiration after commencement, a term that matches the dates, free rent within the term, no email, phone or ID number in the text. A comp names no person or company. With the default share profile it also needs the deal's starting rent, escalations, free rent, TI, property type, an expense basis other than unknown, and stated rights. When valid and a starting rent is given, ner.fact is a computed lease.net_effective_rent fact (formula calc.net_effective_rent@1, straight-line and discounted at discount_rate_annual, on the comp's own expense basis; no conversion between full service and net). Returns { valid, issues, warnings, ner }. Call before sharing a comp.

Search the 6,994 lease comps from the U.S. General Services Administration's Lease Inventory (October 2026 file, FactLot release lease-comps-gsa-2026-11-04), bundled with FactLot: works offline and on the hosted API, no registry needed. READ THE CAVEAT: the tenant in every one of these leases is the federal government (GSA, for an agency); they are not market comps for private tenants, and the rent is the current annual rent in GSA's file divided by the rentable SF, not the starting rent (no escalations, free rent, TI or commissions are known). Filter by state, 5-digit county FIPS, city, ZIP, a radius around a latitude/longitude (GSA's own coordinates; nothing is geocoded), rentable SF, commencement date, rent per SF, property type (office, industrial, other) and expense basis; sort; limit (default 25, at most 200). Each comp gives its FactLot lease ID, GSA lease number, address, county FIPS, building ID, landlord (organisations only; individuals are never stored), rentable SF, commencement, expiration, term, early-termination date, annual rent, rent per SF per year, property type, expense basis and the row of the GSA file it comes from. summary gives the count and the median, quartiles and range of rent per SF over every match, labelled as statistics of GSA leases. Every answer carries the caveat and the citation (GSA file URL, SHA-256 document ID, as-of and retrieval dates, licence: public domain). Cite them, and never mix these comps silently into market comps.

Everything the FactLot Registry knows about a parcel, legal entity, or building: status, current cited facts (owner of record, situs address, property category, areas, values), ownership links, external IDs, and for a parcel the building it belongs to (condominium units roll up into one building). value_history (parcels) lists market and appraised value by tax year from every snapshot, newest first, each value cited; a tax year two snapshots value differently appears once per value. as_of gives the facts as they stood on a date. warnings flags area facts that look wrong (building area above 40 times the land area, a land area of 0); the facts themselves are as the source publishes them. A building record can carry debt.cmbs_loan facts (one per CMBS trust holding a note of its loan: balance, rate, maturity, payment status, servicer, special-servicing dates, NOI, DSCR) and an entity record can carry entity.parent facts (the SEC registrant that lists it as a subsidiary in Exhibit 21), each cited to its SEC filing. A miss says whether the county or entity registry is loaded. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Find a parcel's FactLot URN from state FIPS, county FIPS, and APN, if the registry holds it. A miss returns urn null with coverage: whether that county is loaded in this registry. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Find the FactLot URN for an ID from another system, e.g. system "sdat_account" (a Maryland SDAT account number) or, where Texas is hosted, "hcad_account" (a Harris CAD account number). Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Find commercial parcels by situs address. Matches whole words of the street line (the part before the first comma), normalized: 'Street' = 'St', 'Northwest' = 'N.W.' = 'NW'; a suite, unit, '#' or floor is ignored. Give a house number ('1200 Main', '1200 Main St NW') or a street name with its type ('Main St'); a city or a part of a word alone matches nothing. No match returns coverage: what this registry holds. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Find registered business entities (LLCs, LPs, corporations) by name. Natural persons are not searchable. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Commercial parcels currently linked to a legal entity as owner of record (inferred links carry a confidence), each with the building it belongs to, plus a per-building summary so condominium units count once per building. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

The counties (with parcel and building counts), entity registries, and crosswalk systems this FactLot Registry file holds, each with its sources and as-of dates. Call it before concluding that a parcel or entity does not exist: a miss outside these regions means not loaded, not absent. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Takes no parameters.

Candidate comparable parcels for a Texas unequal-appraisal comparison (Tax Code §41.43(b)(3)), from one tax year of the subject's appraisal district roll (the newest year whose roll gives the subject a value, or tax_year), with every field of the subject and the candidates read from that year's roll only: same county and tax year, the same state property category code, improvement area within area_band of the subject's, year built within year_band years when both are known; parcels sharing the subject's neighborhood code first (when the roll gives one), then its ZIP code, then the rest of the county if fewer than min_matches. Each candidate and the subject are shaped for calc_tx_unequal_appraisal (id, value and value_basis, areas, year built, codes, citation of the value fact); the subject adds its value history by tax year. selection echoes the rule, the effective parameters, the tax year and roll sources used, and which tier each candidate came from; Each candidate's citation.document_id names its entry in sources, which gives that snapshot's license, attribution, ai_use and redistribution: relay them with the candidate. Candidates under FactLot's default rule, a design choice, not a legal standard; a person decides which, if any, to use. For evidence calculations only: FactLot does not represent property owners, file protests, or advise whether to protest. Not an appraisal or an opinion of value (Tex. Occ. Code §1103.003(1)); not legal or tax advice and not a substitute for the advice of an attorney. Never returns owner names, mailing addresses, or ownership facts. Do not look up the owners of candidate parcels; ownership is not needed for this comparison. Texas parcels only. Tarrant County is not served by the hosted registry while the publisher's terms for AI use are unclear. Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

registry_tx_equity_candidates for many subjects in one call (1–50, e.g. a consultant's client parcels): each subject's id (your label, echoed back) and its urn, or county_fips and apn, plus the rule parameters once for every subject (area_band, year_band, min_matches, limit, tax_year). Each entry of results is that subject's answer from registry_tx_equity_candidates (subject, candidates, selection, sources, warnings) or that subject's error (error, message, issues, and coverage on a miss), so one subject outside Texas, in Tarrant County, or not in the registry does not fail the others; the Texas-only and Tarrant checks apply to each subject. The selection rule and the notice appear once at the top (rule, notice) instead of in every answer; summary counts subjects, answered and errors. Candidates per subject only: this tool never runs calc_tx_unequal_appraisal and never picks comparables; a person decides, for each subject, which candidates (if any) to use, and only those go to calc_tx_unequal_appraisal. Relay each candidate's source rights from that subject's sources. For evidence calculations only: FactLot does not represent property owners, file protests, or advise whether to protest. Not an appraisal or an opinion of value (Tex. Occ. Code §1103.003(1)); not legal or tax advice and not a substitute for the advice of an attorney. Never returns owner names, mailing addresses, or ownership facts; do not look up the owners of candidate parcels. On the hosted API each answered subject counts as one registry lookup (a subject with an error is not counted). Requires a FactLot Registry (public-record facts about commercial property, each cited to the source file and record).

Search FactLot's knowledge base (tools, inputs, CRE predicates, ID and fact specifications). Returns matching document ids, titles, and URLs; call fetch for full text. A query on a subject the knowledge base does not cover returns no results and a note.

Fetch the full text of a FactLot knowledge document by the id returned from search. With a registry loaded, a registry fact's source document_id (fl:document:sha256-…) returns that source snapshot: publisher, dataset, URL, retrieval date, as-of date, licence, AI-use and redistribution rights, file name and size.

Return the FactLot data model (Fact, Provenance, SourceRef, Rights, Relationship) as JSON Schema.

Takes no parameters.