Inputs
| Field | Type | Valid domain |
|---|---|---|
| currentAge | int | 18 – 65 |
| currentSavings | float | 0 – 1,000,000 |
| annualIncome | float | 30,000 – 500,000 |
| annualExpenses | float | 20,000 – 300,000 |
| savingsRate | float | 0.05 – 0.8 |
| expectedReturn | float | 0.02 – 0.12 |
| withdrawalRate | float | 0.02 – 0.06 |
All fields required. Out-of-domain values are rejected with per-field errors — never clamped. Unknown fields are rejected.
Sentinel values
retirementAge=100→ FIRE not reached by age 100
Responses annotate these in a sentinels array with a triggered flag per run.
Live example — generated from the real engine
Request
POST /api/v1/models/fire
{
"currentAge": 42,
"currentSavings": 500000,
"annualIncome": 265000,
"annualExpenses": 160000,
"savingsRate": 0.43,
"expectedReturn": 0.07,
"withdrawalRate": 0.04
}Response (chart arrays compacted)
{
"ok": true,
"model": "fire",
"specVersion": "1.0.1",
"contractUrl": "/api/v1/models/fire",
"specUrl": "/api/v1/models/fire/spec",
"inputs": {
"currentAge": 42,
"currentSavings": 500000,
"annualIncome": 265000,
"annualExpenses": 160000,
"savingsRate": 0.43,
"expectedReturn": 0.07,
"withdrawalRate": 0.04
},
"outputs": {
"fireNumber": 4000000,
"retirementAge": 57,
"yearsToFire": 15,
"annualSavings": 113950,
"projectedPortfolio": [
{
"age": 42,
"balance": 500000
},
{
"age": 43,
"balance": 648950
},
"… 57 more"
]
},
"sentinels": [
{
"field": "retirementAge",
"value": 100,
"meaning": "FIRE not reached by age 100",
"triggered": false
}
],
"assumptions": [
"Implements model spec fire v1.0.1 (dual-implementation verified)."
],
"facts": [],
"record": {
"sha256": "0557f59c07ad9a48ef481d92228164150d549e1a95b20afe4568d26e05556103",
"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.