OpenChainGraph Suite · ART-332 · US Mortgage Compliance

Amortization Schedule Builder

Builds a full period-by-period amortization schedule for level-payment, adjustable-rate (index plus margin, caps, recast), interest-only, balloon, and temporary buydown (2-1 or 3-2-1) loans, following the unit-period and odd-days conventions in 12 CFR 1026 Appendix J. The output feeds directly into the Reg Z Appendix J APR Solver as its advances/payments input.

Reg Z Appendix J Level Payment / ARM / IO / Balloon / Buydown Cents-Integer Math Feeds APR Solver

🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.

Schedule parameters

Schedule type

Loan amount ($)

Note rate (annual %)

Initial/fixed rate for level_payment, ARM, IO, balloon, and the full note rate a temp_buydown eventually pays.

Number of payments

Periods per year

Payment override ($, level_payment only)

Leave blank to auto-compute the level payment via the standard annuity formula.

Odd days (App J unit-period)

Unit period days

Interest-only

IO periods

Balloon

Nominal amortization periods

Payment is computed on this longer term; the note matures at Number of payments above.

ARM: index, margin, caps, resets

Margin (%)

Periodic cap (+/- pts)

Lifetime cap (+pts vs initial)

Lifetime floor (pts vs initial, negative)

Recast at each reset

Rate changes (period_index:index_value_pct, one per line)

No live index fetching — supply the resolved index value your contractual lookback observed at each reset.

Temporary buydown

Buydown type

Schedule summary

Schedule (first 6 / last 3 periods)

#	t (periods)	Payment	Principal	Interest	Ending balance

Advances / payments (feeds ART-215)

advances[]1 entry: loan amount at t=0

payments[]

Totals and digest

Execution Hash (SHA-256)

Ask your agent

Copy this paragraph into Claude, OpenClaw, or any MCP-aware agent to run this exact tool, with this sample, and verify the artifact.

Run the AINumbers MCP tool `build_amortization_schedule`. Task: Deterministic amortization schedule builder covering level-payment, ARM (index plus margin, periodic and lifetime caps, recast), interest-only, balloon, and temporary buydown (2-1 or 3-2-1) structures, per the unit-period and odd-days conventions in 12 CFR 1026 Appendix J.
Call it with arguments: {"policy_parameters":{"schedule_type":"level_payment","loan_amount":6000,"note_rate_pct":12,"num_payments":24,"periods_per_year":12}}
Verify before trusting: call `verify_execution_hash` on mcp.ainumbers.co (https://mcp.ainumbers.co/mcp) with the parameter `claimed_hash` set to the returned `execution_hash`, passing the full artifact the run returned (the object containing `policy_parameters` + `output_payload` + `execution_hash`; equivalently `policy_parameters` + `output_payload` with `claimed_hash`), not the bare hash string.
Return the ledger link https://ledger.ainumbers.co/ so a human can re-verify without contacting us.
PII rule: All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Open the tool with the sample prefilled: https://ainumbers.co/chaingraph/art-332-build-amortization-schedule.html#p=v1.H4sIAAAAAAAA_wFvAJD_eyJzY2hlZHVsZV90eXBlIjoibGV2ZWxfcGF5bWVudCIsImxvYW5fYW1vdW50Ijo2MDAwLCJub3RlX3JhdGVfcGN0IjoxMiwibnVtX3BheW1lbnRzIjoyNCwicGVyaW9kc19wZXJfeWVhciI6MTJ9ndWfYm8AAAA