# Qotien IFI Calculator — French Wealth Tax (Impôt sur la Fortune Immobilière) Simulator

> Qotien IFI Calculator — French Wealth Tax (Impôt sur la Fortune Immobilière) Simulator is a paid API for AI agents from app.qotien.fr, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).

Computes the French IFI (Impôt sur la Fortune Immobilière) wealth tax due given a household's taxable real estate assets, deductible debts, and optionally household income for the art. 979 cap calculation.

## Facts

- Endpoint: POST https://app.qotien.fr/api/fiscal/v1/calc/ifi
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/qotien-ifi-calculator-french-wealth-tax-imp-t-sur-la-fortune-immobili-63bba2bc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mGK6LbRauKak_aypKsaG5

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability qotien-ifi-calculator-french-wealth-tax-imp-t-sur-la-fortune-immobili-63bba2bc -d '<json body>'
```

Example prompt: Can you calculate the IFI I'd owe this year? My taxable real estate patrimony (after the 30% main residence deduction) is €2,400,000, I have €300,000 in deductible mortgage debt, my household income is €180,000, and I already owe €45,000 in income tax and social contributions.

## When to prefer this

Choose this endpoint when you need a legally-sourced, CGI-compliant French IFI calculation for a household or client, especially when you need debt deduction (art. 974) and/or the art. 979 income-cap (plafonnement) applied. Prefer it over generic tax calculators because it cites Légifrance/BOFiP sources, handles the 1.3M€ threshold and progressive bracket logic, and returns a confidence indicator. Not suitable for non-French tax systems or for simulating IR/PER (use sibling endpoints for those).

## Known failure modes

- Missing required field patrimoine_immobilier_taxable → validation error
- Negative values for patrimony or debts → schema minimum violation
- revenu_foyer absent but autres_impots_annuels provided → plafonnement ignored/warning
- Patrimony below 1.3M€ threshold → IFI = 0 returned (not an error)
- API payment not processed (x402) → 402 Payment Required before result delivered

## How this service works

Simulateur IFI, PER, IR et retraite (32 régimes). Logiciel CGP : bilan patrimonial, déclaration 2042, LMNP. Chiffres sourcés Légifrance et BOFiP. 14 jours d'essai.

## Output

A JSON object with ok=true on success, containing a result object with the IFI amount in EUR, a human-readable label, a confidence level (typically 'fiable' for fiscal computations), the legal sources used (e.g. CGI art. 964, art. 977, art. 979), the fiscal vintage (barème year), and an optional capping warning. Returns ok=false with an error field on failure.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "dettes": {
   "type": "number",
   "default": 0,
   "minimum": 0,
   "description": "Dettes déductibles rattachées à l'immobilier taxable (€). La limitation art. 974 s'applique au-delà de 5 M€ de patrimoine."
  },
  "revenu_foyer": {
   "type": "number",
   "minimum": 0,
   "description": "Revenus du foyer de l'année (€). Fourni → déclenche le plafonnement art. 979. Absent → IFI rendu avant plafonnement."
  },
  "autres_impots_annuels": {
   "type": "number",
   "default": 0,
   "minimum": 0,
   "description": "IR + prélèvements sociaux + CEHR déjà dus au titre de l'année (€), pour le calcul du plafonnement art. 979. Ignoré si revenu_foyer absent."
  },
  "patrimoine_immobilier_taxable": {
   "type": "number",
   "minimum": 0,
   "description": "Valeur du patrimoine immobilier taxable BRUT (avant dettes) entrant dans l'assiette IFI (€) — résidence principale après abattement 30 %, biens locatifs, SCPI part immobilière, etc."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "ok",
   "domaine",
   "capability",
   "result",
   "confiance",
   "sources",
   "millesime_fiscal"
  ],
  "properties": {
   "ok": {
    "type": "boolean",
    "description": "true = succès ; false = erreur (champ \"error\" présent à la place de result)."
   },
   "result": {
    "type": "object",
    "properties": {
     "unit": {
      "type": "string",
      "description": "Unité de value (EUR, PERCENT, RATE…)."
     },
     "label": {
      "type": "string",
      "description": "Libellé lisible du résultat."
     },
     "value": {
      "type": "number",
      "description": "Valeur principale (quand le résultat est scalaire)."
     },
     "confiance": {
      "enum": [
       "fiable",
       "estime",
       "partiel",
       "non_calculable",
       "sourcee",
       "variable"
      ],
      "type": "string",
      "description": "Confiance propre au résultat retraite (prime sur la confiance de capacité)."
     }
    },
    "description": "Résultat. Contient typiquement { value:number, unit:string, label:string } ; les outils retraite ajoutent confiance, fourchette, et le détail par régime."
   },
   "domaine": {
    "enum": [
     "fiscal",
     "retraite",
     "referentiel",
     "qotien"
    ],
    "type": "string",
    "description": "Domaine de la capacité."
   },
   "sources": {
    "type": "array",
    "items": {
     "type": "string"
    },
    "description": "Sources primaires/légales du calcul."
   },
   "confiance": {
    "enum": [
     "fiable",
     "estime",
     "partiel",
     "non_calculable",
     "sourcee",
     "variable"
    ],
    "type": "string",
    "description": "Niveau de confiance de CE résultat (fiscal = fiable ; retraite = variable)."
   },
   "capability": {
    "type": "string",
    "description": "Nom de la capacité appelée."
   },
   "referentiel": {
    "type": "string",
    "description": "Version du référentiel sourcé utilisé."
   },
   "annee_revenus": {
    "type": "number",
    "description": "Année des revenus concernés."
   },
   "avertissement": {
    "type": "string",
    "description": "Avertissement d'usage (résultat brut, pas un conseil personnalisé)."
   },
   "millesime_fiscal": {
    "type": "string",
    "description": "Millésime fiscal (année des barèmes appliqués)."
   }
  }
 },
 "example": {
  "ok": true,
  "result": {
   "unit": "EUR",
   "label": "Impôt sur la fortune immobilière (IFI)",
   "value": 0
  },
  "domain
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/qotien-ifi-calculator-french-wealth-tax-imp-t-sur-la-fortune-immobili-63bba2bc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from app.qotien.fr](https://www.zero.xyz/host/app.qotien.fr/llms.txt)