Inputs
| Field | Type | Valid domain |
|---|---|---|
| traditionalBalance | float | 10,000 – 5,000,000 |
| annualConversion | float | 1,000 – 500,000 |
| annualOtherTaxableIncome | float | 0 – 500,000 |
| filingStatus | choice | single | married |
| ladderYears | int | 1 – 20 |
| growthRate | float | 0 – 0.12 |
- The TY2026 federal bracket table is applied to every ladder year (no bracket inflation); annualOtherTaxableIncome is taxable income after deductions.
All fields required. Out-of-domain values are rejected with per-field errors — never clamped. Unknown fields are rejected.
Live example — generated from the real engine
Request
POST /api/v1/models/roth-conversion-ladder
{
"traditionalBalance": 2505000,
"annualConversion": 251000,
"annualOtherTaxableIncome": 250000,
"filingStatus": "single",
"ladderYears": 11,
"growthRate": 0.06
}Response (chart arrays compacted)
{
"ok": true,
"model": "roth-conversion-ladder",
"specVersion": "1.0.0",
"contractUrl": "/api/v1/models/roth-conversion-ladder",
"specUrl": "/api/v1/models/roth-conversion-ladder/spec",
"inputs": {
"traditionalBalance": 2505000,
"annualConversion": 251000,
"annualOtherTaxableIncome": 250000,
"filingStatus": "single",
"ladderYears": 11,
"growthRate": 0.06
},
"outputs": {
"totalConverted": 2761000,
"totalConversionTax": 964295.75,
"averageEffectiveRate": 0.34925597609561754,
"remainingTraditionalBalance": 771882.6481181877,
"yearlyData": [
{
"year": 1,
"conversion": 251000,
"tax": 87663.25,
"accessibleInYear": 6,
"endingBalance": 2389240
},
{
"year": 2,
"conversion": 251000,
"tax": 87663.25,
"accessibleInYear": 7,
"endingBalance": 2266534.4
},
"… 9 more"
]
},
"sentinels": [],
"assumptions": [
"Implements model spec roth-conversion-ladder v1.0.0 (dual-implementation verified).",
"The TY2026 federal bracket table is applied to every ladder year (no bracket inflation); annualOtherTaxableIncome is taxable income after deductions."
],
"facts": [
{
"id": "irs.brackets.single.top-of-10pct.2026",
"label": "Top of 10% ordinary bracket, single (vintage marker for the TY2026 table)",
"value": 12400,
"period": "TY2026",
"source": "IRS TY2026 inflation adjustments (Rev. Proc. 2025-32)"
},
{
"id": "irs.brackets.mfj.top-of-10pct.2026",
"label": "Top of 10% ordinary bracket, MFJ (vintage marker for the TY2026 table)",
"value": 24800,
"period": "TY2026",
"source": "IRS TY2026 inflation adjustments (Rev. Proc. 2025-32)"
}
],
"record": {
"sha256": "fd18bcecf8fe6f67988a3e1731fe031b0bacd48b2f23017f0a39d2785cb58e17",
"fields": [
"model",
"specVersion",
"inputs",
"outputs"
],
"howToVerify": "Store this record with any advice or agent output built on these numbers. To verify later: build {model, specVersion, inputs, outputs} from the stored response, serialize as JSON with object keys sorted recursively (no whitespace), and SHA-256 it — a match proves the numbers came from this spec version with these inputs, unaltered."
},
"disclaimer": "Illustrative planning model, not financial advice. Outputs follow the published model spec exactly; read the spec for assumptions and exclusions before relying on any number."
}This example is executed against the production engine when the page builds — it cannot drift from the API's real behavior.