For developers

Public API.

Read access to the French public data we ingest: regions, départements, communes and cadastral parcels, with the statistics and enrichments shown on the site. REST, JSON, one key in a header. Free for non-commercial use. And an MCP server for AI assistants.

11 endpoints MCP server 39 public sources Etalab Open Licence 2.0 openapi.json
Get a key

Create an account.

Keys are self-service: two minutes online, no need to email us.

  1. Sign up with an email and a password, or with Google.
  2. Open the confirmation link we email you.
  3. In your account, click “Create a key”. It is shown only once, so copy it.

The free plan is included; paid plans are subscribed from your account, cancel any time.

PlanPricePer dayPer minuteUse
FreeFree100 requests10 requestsNon-commercial
Standard€19 excl. VAT / month2,000 requests60 requestsCommercial use allowed
Pro€79 excl. VAT / month25,000 requests300 requestsCommercial use allowed

Limits apply per account, across all its keys. A key identifies an integration, not a visitor: do not ship it in a public front end. Every response returns X-Plan, X-Quota-Used and X-Quota-Remaining. Anything that doesn’t fit (public bodies, research, higher volumes): email us at contact@lagrandecarte.fr.

curl -H "X-API-Key: YOUR_KEY" \
  "https://lagrandecarte.fr/api/v1/communes/18033?include=stats"
AI assistants

MCP server.

The same data, right inside Claude, ChatGPT, Cursor or any MCP-compatible client: the assistant geocodes the address, finds the parcel and reads its risks, zoning or sales without you touching the API. Each tool calls the matching REST endpoint: same account, same limits, one tool call counts as one request.

https://lagrandecarte.fr/mcp

Step-by-step connection guide: lagrandecarte.fr/en/mcp.

From the assistant’s settings

Add a custom connector with this URL in your assistant. It sends you to La Grande Carte: sign in (or create an account), allow access, and an “MCP · …” key is created automatically in your account. Revoking it disconnects the assistant.

With a key

For clients that accept a header, create a key from your account. Claude Code:

claude mcp add --transport http lagrandecarte https://lagrandecarte.fr/mcp \
  --header "X-API-Key: YOUR_KEY"

JSON configuration (Cursor, Claude Desktop, VS Code…):

{
  "mcpServers": {
    "lagrandecarte": {
      "type": "http",
      "url": "https://lagrandecarte.fr/mcp",
      "headers": {
        "X-API-Key": "YOUR_KEY"
      }
    }
  }
}

Example prompts

  • “What do you know about the commune of Bosdarros? How good is the tap water?”
  • “I’m visiting a house at 4 rue Porte Jaune in Bourges: natural risks, zoning, recent sales nearby?”
  • “Compare median income, rents and crime between Pau and Tarbes.”
  • “Poverty rate and life expectancy in Pyrénées-Atlantiques compared with Nouvelle-Aquitaine?”

Your assistant only sends tool parameters (a commune, an address), never your conversation: see the privacy policy. Questions or problems: contact@lagrandecarte.fr.

ToolDescription
get_communeEverything on a commune: population, income, rents, tap-water and air quality, crime, climate, mayor, finances… (statistics included)
search_addressFind a commune, an address or a locality; returns the INSEE code and coordinates
get_parcel_enrichmentsFull report on a parcel: risks, zoning, sales, energy ratings, noise, networks…
get_parcel_at_pointThe cadastral parcel at a point
get_parcelA parcel by its cadastral reference (IDU)
get_departementA département with its statistics, optionally its communes
get_regionA région with its statistics, optionally its départements
find_communeThe commune containing a point
list_communesThe communes of a département
list_departementsThe départements, optionally of one région
list_regionsThe régions
Quick reference

Endpoints.

MethodPathDescription
GET/api/v1Service index — the only call that needs no key
GET/api/v1/regionsThe 18 regions
GET/api/v1/regions/{code}One region · include=geometry,stats,departements
GET/api/v1/departementsThe 96 metropolitan départements · ?region=
GET/api/v1/departements/{code}One département · include=geometry,stats,communes
GET/api/v1/communesThe communes of a département (?departement=) or the one containing a point (?lat=&lon=)
GET/api/v1/communes/{codeInsee}One commune · include=geometry,stats
GET/api/v1/adresses?q=Geocode an address or a place (Base Adresse Nationale)
GET/api/v1/parcelles?lat=&lon=The cadastral parcel at a point
GET/api/v1/parcelles/{idu}One parcel · include=geometry
GET/api/v1/parcelles/{idu}/enrichmentsEverything we know about the parcel

Overseas départements are not yet in the administrative boundaries table: /departements/974 returns 404, but their communes and parcels are served (/communes?departement=974).

The data is published under the Etalab Open Licence 2.0: free reuse, including commercial, provided you credit the source. Mentioning “La Grande Carte” with a link is enough.

Interactive documentation

Try the calls.