---
title: "Simulate a rent revision (server-resolved IRL values)"
method: POST
path: "/public/tools/irl/simulate-by-quarters"
tags: ["Public Tools"]
---

# Simulate a rent revision (server-resolved IRL values)

`POST /public/tools/irl/simulate-by-quarters`

## Request

- Base URL: `https://api.faireplace.com/api`
- URL: `https://api.faireplace.com/api/public/tools/irl/simulate-by-quarters`
- Auth: none required

Stricter variant of `POST /public/tools/irl/simulate`: the caller provides only the rent,
the two quarter labels and the region; the server resolves the trusted
INSEE IRL values (no typo risk).

Public, unauthenticated tool.

## Example

```bash
curl -X POST https://api.faireplace.com/api/public/tools/irl/simulate-by-quarters \
  -H "Content-Type: application/json" \
  -d '{
    "current_rent": 850.00,
    "old_irl_quarter": "T2-2023",
    "new_irl_quarter": "T2-2024",
    "effective_date": "2024-07-01",
    "region": "metropole"
  }'
```

## Request body

- IrlSimulateByQuartersRequest: Stricter rent revision: the caller provides only the rent, the two quarter labels and the region. The server resolves the IRL values from its trusted INSEE-backed store.
  - `current_rent` number, required
  - `old_irl_quarter` string, required
  - `new_irl_quarter` string, required
  - `effective_date` string, date, required
  - `region` 'metropole' | 'corse' | 'outre_mer': Regional variant. Default `metropole`.

## Response `200`

Rent revision computed.

- IrlSimulateResponse
  - `previous_rent` number, required
  - `new_rent` number, required
  - `old_irl_quarter` string, required
  - `old_irl_value` number, required
  - `new_irl_quarter` string, required
  - `new_irl_value` number, required
  - `variation_percentage` number, required
  - `effective_date` string, date, required
  - `monthly_increase` number, required
  - `annual_increase` number, required: 12 × monthly increase, rounded to 2 decimals.

## Other responses

- `400`: Bad request
- `422`: Unprocessable Entity
- `500`: Internal Server Error

---

[API](https://skmtc.dev/faireplace/apis/faireplace-property-management-api.md) · [All operations](https://skmtc.dev/faireplace/apis/faireplace-property-management-api/llms.txt) · [OpenAPI document](https://skmtc.dev/faireplace/apis/faireplace-property-management-api/revisions/69de39762919?raw)