Inputs
| Field | Type | Valid domain |
|---|---|---|
| expectedCurrentYearTax | float | 0 – 500,000 |
| priorYearTax | float | 0 – 500,000 |
| priorYearAgi | float | 0 – 3,000,000 |
| expectedWithholding | float | 0 – 500,000 |
- IRC §6654 safe harbors with the non-MFS 110% AGI trigger ($150,000); four equal installments — the annualized-income method is out of scope.
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/quarterly-estimates
{
"expectedCurrentYearTax": 250000,
"priorYearTax": 250000,
"priorYearAgi": 1500000,
"expectedWithholding": 250000
}Response (chart arrays compacted)
{
"ok": true,
"model": "quarterly-estimates",
"specVersion": "1.0.0",
"contractUrl": "/api/v1/models/quarterly-estimates",
"specUrl": "/api/v1/models/quarterly-estimates/spec",
"inputs": {
"expectedCurrentYearTax": 250000,
"priorYearTax": 250000,
"priorYearAgi": 1500000,
"expectedWithholding": 250000
},
"outputs": {
"requiredAnnualPayment": 225000,
"safeHarborUsed": "90% of current year",
"requiredAfterWithholding": 0,
"quarterlyPayment": 0,
"balanceDueAtFiling": 0,
"deMinimisNoPenalty": true
},
"sentinels": [],
"assumptions": [
"Implements model spec quarterly-estimates v1.0.0 (dual-implementation verified).",
"IRC §6654 safe harbors with the non-MFS 110% AGI trigger ($150,000); four equal installments — the annualized-income method is out of scope."
],
"facts": [],
"record": {
"sha256": "f970e8672bdc401067b50d8296e514e1446506f57aa09a5e5250da6869da1a20",
"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.