French public data

Foncier. Explore an address.

Cadastre, sales, planning, energy and risks in one record. Each value includes its source; missing information includes its reason.

One address · five data layers

A record presents published data. It does not replace an official risk statement, planning certificate or valuation.

Official place names and data labels are reproduced in French as published.

What about an AI assistant?

MCP is the protocol that lets an assistant query these same tools. These three demonstrations were recorded on 13 October 2026 with Claude connected to foncier-mcp. Real calls and abbreviated results; the answers below summarise their reasoning. These are not live searches.

QuestionCan this parcel in Lozère be built on?

Recorded call: get_zoning abbreviated result

get_zoning({"parcel_id": "481670000A0439"})

{
  "parcel": {
    "value": {"commune": "Saint-Laurent-de-Veyrès", "section": "0A", "numero": "0439", "area_m2": 200},
    "source": "apicarto_cadastre", "retrieved_at": "2026-10-13T06:34:29+00:00"
  },
  "municipality": {
    "value": {"name": "SAINT-LAURENT-DE-VEYRES", "is_rnu": true},
    "source": "apicarto_gpu"
  },
  "zones": {
    "value": null,
    "reason": "commune under the RNU (reglement national d urbanisme): no local planning document is in force, so there is no zoning to return"
  },
  "public_utility_easements": {"value": [], "source": "apicarto_gpu"}
}

Sourced answer, summarised

The municipality is governed by national planning rules (RNU). There is no local zone to read. The queried data does not establish whether this parcel can be built on.

QuestionIs Place Pey Berland in Bordeaux exposed to flooding?

Recorded call: get_risks abbreviated result

get_risks({"address": "Place Pey Berland 33000 Bordeaux"})

"commune": {
  "risks_inventory": ["Inondation", "Par une crue à débordement lent de cours d'eau",
                      "Mouvement de terrain", "Tassements différentiels", "Séisme",
                      "Radon", "Risque industriel"],
  "seismic_zone": {"label": "2 - FAIBLE"},
  "radon_potential": {"class": "2", "meaning": "medium potential"},
  "natural_disaster_orders": {"count": 51},
  "flood_risk_territories": [{"label": "BORDEAUX",
    "hazards": ["Inondation", "Par une crue à débordement lent de cours d'eau", "Par submersion marine"]}]
},
"point": {
  "clay_shrink_swell": {"label": "Exposition moyenne"},
  "flood_zoning_100m": {"count": 0},
  "underground_cavities_500m": {"count": 0},
  "ground_movements_500m": {"count": 0},
  "classified_installations_1km": {"count": 23}
}
(source : georisques, lu le 2026-10-13 ; listes abrégées)

Sourced answer, summarised

Bordeaux is in an area of significant flood risk. At the queried point, no zone in this mapping is published within 100 m. This does not guarantee no risk: municipality-level data and point-level data answer different questions.

QuestionWhat are property sale prices on Rue Brûlée in Strasbourg?

Recorded call: get_parcel_sales abbreviated result

get_parcel_sales({"address": "9 Rue Brulee 67000 Strasbourg", "radius_m": 300})

{
  "parcel": {"value": {"id": "67482000640001", "commune": "Strasbourg", "area_m2": 4033}},
  "sales_on_parcel": {
    "value": null,
    "reason": "DVF does not cover department 67 (Alsace-Moselle keeps the Livre foncier; Mayotte is not published)"
  },
  "errors": [{"code": "not_covered", "retryable": false, "source": "dvf_geo"}]
}

Sourced answer, summarised

DVF does not cover Bas-Rhin. The service explicitly reports the coverage gap, rather than an empty list that might imply no properties were sold.

From a need to a service

I designed Foncier from the research I did for my property projects: problem definition, architecture, development with AI assistance, testing and deployment. The public code exposes the decisions; the case study explains their evaluation and limitations.

Read the case study →Code and MCP installation ↗

Privacy, sources and demo limits

The demo allows 10 searches per hour per visitor and 300 per day in total. The address is sent in a request body to the service, hosted by Scaleway in France, then to the queried public sources. The service does not store or log the address.

From the third character, input is sent to IGN Géoplateforme autocomplete, which sees your IP address. Your browser loads the Plan IGN background directly: IGN sees the displayed area and your IP address. No cookies or trackers.

Sources: IGN geocoder and cadastre, DGFiP DVF via data.gouv.fr, Géoportail de l’urbanisme, ADEME and Géorisques. Sales are displayed only on request, never published as fixed pages.