{
  "tool_id": "art-332-build-amortization-schedule",
  "tool_version": "1.0.0",
  "display_name": "Amortization Schedule Builder",
  "mcp_name": "build_amortization_schedule",
  "mandate_type": "compliance_mandate",
  "wave": 59,
  "gpu": false,
  "url": "https://ainumbers.co/chaingraph/art-332-build-amortization-schedule.html",
  "description": "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. Returns the full period-by-period schedule (principal, interest, ending balance), totals, a schedule_digest, and advances/payments arrays shaped for direct use as the actuarial APR solver's input. Cents-integer fixed-point math throughout; no floating-point drift.",
  "input_schema_ref": "chaingraph/art-332-build-amortization-schedule.html#manifest",
  "consumes": [],
  "feeds": [
    "art-215-reg-z-appendix-j-apr"
  ],
  "status": "live",
  "conformance_fixtures": true,
  "compute_capability": "server",
  "compute_images": [{"system":"sha256-source","image_id":"sha256:8885c70d3b73687cac1d701f769dca9e13c67e4101c9ff6cd9707922f141439b","valid_from":"2026-07-10"},{"system":"risc0","image_id":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","valid_from":"2026-06-28"}],
  "export_capability": [
    "json"
  ],
  "compute_proof_ready": "ready",
  "compute_proof": {"type":"ZkVmReceipt","system":"risc0","receiptFormat":"groth16-bn254","imageId":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","seal":"F2IU+UOo8i+xJ9p6reR9Cxlvl0UE4bgvDL3CTaeA0B0Clu7SOVOsI8kcpaQvJxh75mT1nvqozveWpHhP1v9QUyE69Ufid+YVfVHZc2jXX9yaSf49zeCRoeLRbSUgG3g/LLi0fBixaO3ePTJIqNAfjBsMLcdpJa5mDc3W9CHPfRImp1zaQEasEUpku/gJ+McRX6ER8FZxLYN5lza0t4uFXBKR62FCgbHmgQYETytOy3pJ4F6lBfpOjtsfnQZu/3Q/Dnak7wUxWMRQa8Mxf7YcYNSRGHUzEOhdD9dMALIDnugjDygvgK4rrmLwdFvBHkp+pTcj6L6K+H8+M+NsrOhIvA==","journal":{"chaingraph_version":"0.4.0","kernel_digest":"sha256:8885c70d3b73687cac1d701f769dca9e13c67e4101c9ff6cd9707922f141439b","output":{"advances":[{"amount":6000,"periods_from_consummation":0}],"loan_amount":6000,"note":"Odd-days fraction shifts periods_from_consummation for the first period per Appendix J unit-period convention; it does not change per-period interest/principal allocation. Feed advances/payments directly into compute_reg_z_appendix_j_apr (art-215) for an actuarial APR on this schedule.","note_rate_pct":12,"num_payments":24,"odd_days":0,"payment_amount":282.44,"payments":[{"amount":282.44,"periods_from_consummation":1},{"amount":282.44,"periods_from_consummation":2},{"amount":282.44,"periods_from_consummation":3},{"amount":282.44,"periods_from_consummation":4},{"amount":282.44,"periods_from_consummation":5},{"amount":282.44,"periods_from_consummation":6},{"amount":282.44,"periods_from_consummation":7},{"amount":282.44,"periods_from_consummation":8},{"amount":282.44,"periods_from_consummation":9},{"amount":282.44,"periods_from_consummation":10},{"amount":282.44,"periods_from_consummation":11},{"amount":282.44,"periods_from_consummation":12},{"amount":282.44,"periods_from_consummation":13},{"amount":282.44,"periods_from_consummation":14},{"amount":282.44,"periods_from_consummation":15},{"amount":282.44,"periods_from_consummation":16},{"amount":282.44,"periods_from_consummation":17},{"amount":282.44,"periods_from_consummation":18},{"amount":282.44,"periods_from_consummation":19},{"amount":282.44,"periods_from_consummation":20},{"amount":282.44,"periods_from_consummation":21},{"amount":282.44,"periods_from_consummation":22},{"amount":282.44,"periods_from_consummation":23},{"amount":282.47,"periods_from_consummation":24}],"periods_per_year":12,"regulatory_basis":"12 CFR 1026 Appendix J (Reg Z general actuarial equation, unit-period and odd-days conventions). Buydown modeling (temp_buydown) is a schedule-construction convenience, not an Appendix J concept.","schedule":[{"ending_balance":5777.56,"interest":60,"payment_amount":282.44,"period_index":1,"periods_from_consummation":1,"principal":222.44},{"ending_balance":5552.9,"interest":57.78,"payment_amount":282.44,"period_index":2,"periods_from_consummation":2,"principal":224.66},{"ending_balance":5325.99,"interest":55.53,"payment_amount":282.44,"period_index":3,"periods_from_consummation":3,"principal":226.91},{"ending_balance":5096.81,"interest":53.26,"payment_amount":282.44,"period_index":4,"periods_from_consummation":4,"principal":229.18},{"ending_balance":4865.34,"interest":50.97,"payment_amount":282.44,"period_index":5,"periods_from_consummation":5,"principal":231.47},{"ending_balance":4631.55,"interest":48.65,"payment_amount":282.44,"period_index":6,"periods_from_consummation":6,"principal":233.79},{"ending_balance":4395.43,"interest":46.32,"payment_amount":282.44,"period_index":7,"periods_from_consummation":7,"principal":236.12},{"ending_balance":4156.94,"interest":43.95,"payment_amount":282.44,"period_index":8,"periods_from_consummation":8,"principal":238.49},{"ending_balance":3916.07,"interest":41.57,"payment_amount":282.44,"period_index":9,"periods_from_consummation":9,"principal":240.87},{"ending_balance":3672.79,"interest":39.16,"payment_amount":282.44,"period_index":10,"periods_from_consummation":10,"principal":243.28},{"ending_balance":3427.08,"interest":36.73,"payment_amount":282.44,"period_index":11,"periods_from_consummation":11,"principal":245.71},{"ending_balance":3178.91,"interest":34.27,"payment_amount":282.44,"period_index":12,"periods_from_consummation":12,"principal":248.17},{"ending_balance":2928.26,"interest":31.79,"payment_amount":282.44,"period_index":13,"periods_from_consummation":13,"principal":250.65},{"ending_balance":2675.1,"interest":29.28,"payment_amount":282.44,"period_index":14,"periods_from_consummation":14,"principal":253.16},{"ending_balance":2419.41,"interest":26.75,"payment_amount":282.44,"period_index":15,"periods_from_consummation":15,"principal":255.69},{"ending_balance":2161.16,"interest":24.19,"payment_amount":282.44,"period_index":16,"periods_from_consummation":16,"principal":258.25},{"ending_balance":1900.33,"interest":21.61,"payment_amount":282.44,"period_index":17,"periods_from_consummation":17,"principal":260.83},{"ending_balance":1636.89,"interest":19,"payment_amount":282.44,"period_index":18,"periods_from_consummation":18,"principal":263.44},{"ending_balance":1370.82,"interest":16.37,"payment_amount":282.44,"period_index":19,"periods_from_consummation":19,"principal":266.07},{"ending_balance":1102.09,"interest":13.71,"payment_amount":282.44,"period_index":20,"periods_from_consummation":20,"principal":268.73},{"ending_balance":830.67,"interest":11.02,"payment_amount":282.44,"period_index":21,"periods_from_consummation":21,"principal":271.42},{"ending_balance":556.54,"interest":8.31,"payment_amount":282.44,"period_index":22,"periods_from_consummation":22,"principal":274.13},{"ending_balance":279.67,"interest":5.57,"payment_amount":282.44,"period_index":23,"periods_from_consummation":23,"principal":276.87},{"ending_balance":0,"interest":2.8,"payment_amount":282.47,"period_index":24,"periods_from_consummation":24,"principal":279.67}],"schedule_type":"level_payment","totals":{"ending_balance":0,"num_payments":24,"total_interest":778.59,"total_principal":6000},"unit_period_days":30}}}
}