In developmentReconstruction proven
Books, derived from the documents you already have.
TeckOS is building books computed from your documents — every number traceable to its source evidence and the decisions that govern it.
Two property-years reconstructed against the filed 2024 returns, and two prepared for 2025 — all four from their source documents and the decisions that governed them. Each one reproduces byte-for-byte from the same documents and decisions.
One worked trace · Linden Court · 3 units · 2025
Follow payments through the year
Illustration of the mechanism — not a product screen.
1 · Sources & decisions
what you already have
Bank · 3 rent deposits+$4,800.00Servicer · PAYMENTone lump$2,104.55Form 1098 · Box 1year total$14,212.18Servicer · tax paid$1,430.002 · Facts
what TeckOS establishes
Rent · 3 of 3 paid✓ billed4,800.00Split · int / prininferred1,167.06 / 629.49Escrowper statement308.00Tax, from escrow1,430.003 · The month’s P&L
computed, never stored
Rent income4,800.00Mortgage interest(1,167.06)Property tax(1,430.00)Net income · Dec2,202.94Not in the P&L:Principal 629.49: pays down the loan.Escrow 308.00: held for tax and insurance.4 · Schedule E, so far
what falls out
L3 · Rents$57,600.00L9 · Insurance$1,212.00L12 · Interest$14,212.18L14 · Repairs$2,457.50L16 · Taxes$2,860.00The year closes: Line 12 ties to the Form 1098, Lines 9 and 16 to the lender’s year-end statement and servicer history, Line 3 to the bank ✓
The servicer reports each payment as one lump and the 1098 gives only the year’s interest. The escrow part is read from the lender’s statement; the interest/principal split is derived from the 1098 and servicer history, and the interest totals tie to the 1098. Illustrative data; Linden Court is fictional.
One filing entity · two properties · tax year 2025
The sealed year
Every document is hashed. Your decisions are recorded beside those hashes in one year record, and each property’s seal pins that record by its hash. Change anything, and every seal built on it breaks.
Documents · each hashed
Decisions · recorded in the year record
Year record
Property seals
Schedule E · a sample of lines
Three lines per property, shown as examples. Every line of each property’s rental schedule is derived from sealed inputs and traceable to its documents and decisions. Click one to trace it.
The lines shown are a sample; every line of each rental schedule is derived from sealed inputs and traceable to its documents and decisions. Click one to trace it.
Illustrative data. Linden Court and Hawthorn Row are fictional; hashes are shortened for display.
Linden Court · 2025 · one loan
The mortgage year
The servicer reports each month’s payment as one lump. The escrow part is read from the lender’s statement; TeckOS derives the split of the rest into interest and principal. Every total ties out: the interest to the 1098, the principal to the loan balance, and the escrow to the lender’s year-end statement and servicer history.
InterestPrincipalEscrow · 308.00 each month
Mar 2025 · $2,104.55 debit
Interest $1,195.25 is the month’s interest on the $234,172.12 balance. Principal $601.30 is the rest of the fixed $1,796.55 loan payment. Escrow $308.00 is read from the lender’s statement, not derived.
Lands on Schedule E, Line 12.
Payouts come from the servicer history; each is assigned to tax or insurance only when the statement’s totals leave exactly one answer. Lands on Line 16 (taxes $2,860.00) and Line 9 (insurance $1,212.00).
Every debit splits three ways, and every total ties to a document the lender produced. Pick a month to see its split.
Illustrative data. Linden Court is fictional.
Linden Court · 2025
Depreciation, tracked
Every asset carried forward from the last filed return and reconciled to it before a single 2025 figure is computed. Then the same schedule runs forward.
Roof replacement · useful lifeJun 2021 → 2048 · 27.5-yr straight line
201020252055
The water heater is new in 2025, so it isn’t on the filed schedule.
Same schedule, run forward: the appliances finish in 2028, and everything else carries on.
Five assets, one schedule: carried from the filed return, reconciled to it, and computed for 2025. Pick an asset to see its useful life.
Illustrative data. Linden Court is fictional; amounts follow the standard tables.
From your documents to live books
Getting there.
The completeness checks are built; the guided flow is in development.
- 1
Upload your leases and platform exports.
Leases, renewals, amendments and exports — any order.
- 2
The copilot rebuilds your tenancy chains.
It asks only what the documents can't answer.
- 3
Your history ties out to your bank before you go live.
Done means the check passed, not the steps clicked.