Benin home codes

What a code is

Every compound in Benin has an N-Ways code: the short name of its quartier or village and a number of four or five digits, such as Cadjéhoun 1807 or Sainte Rita 12403. Each code is unique in the whole country on its own and leads to the compound’s gate. Codes start provisional and become confirmed when residents agree in the N-Ways app.

• Remembered form, what people say, type and write on plates: Cadjéhoun · 18 07, also without the dot or the space (Cadjéhoun 1807); five digits read as a pair and a hundred (Sainte Rita · 12 403). Any case and the usual spellings (Gbèdji = Gbédji, Ouèssè = Wèssè), the official name in place of the short one, and the commune after a comma if you like (Agata 1500, Cotonou; a commune that contradicts the code is refused). People never see or type a check digit.
• Machine form, for systems, QR codes and links: BJ-COT-12-001-1807-4 (the commune, the arrondissement, the quartier, the number and a Damm check digit that catches every single wrong digit and every swap of two neighbouring digits; .2/1 after it for building 2, gate 1).
• Spot code, for any point: COT 12 · 35G 2PX (machine form BJ-COT-12-S-35G2PX), a 3 m cell of UTM zone 31N framed on its arrondissement; every card also carries its gate’s Plus Code (6FR4995R+7CQ).

In Cotonou the official street comes first, in officialAddress with "coverage": "official-street"; a door number of the 2013 addressing plan takes its place once it is known. No commune or arrondissement is needed to decode a code; municipality is looked up from the position. The model, the engine and the registry of every code are open: github.com/n-ways/open-addresses-benin. The white paper explains every rule.

Look up a code

GET https://map.nways.ng/v1/homecodes/{code}, where code is the remembered or machine form, or a spot code on a compound, URL-encoded. No key is needed.

curl "https://map.nways.ng/v1/homecodes/BJ-COT-12-001-1807-4"

{
  "country": "BJ",
  "home": "Cadjéhoun 1807",
  "machine": "BJ-COT-12-001-1807-4",
  "check": 4,
  "name": "Cadjéhoun",
  "coverage": "official-street",
  "officialAddress": "Rue 12.202, Cotonou",
  "nameProvisional": false,
  "municipality": "Cotonou",
  "fullLine": "Cadjéhoun · 18 07",
  "spoken": "Cadjéhoun, 18 07",
  "status": "provisional",
  "issued": "bulk",
  "entrance": { "lat": 6.3582212, "lng": 2.3911161, "kind": "centre", "source": "map" },
  "location": { "lat": 6.3582212, "lng": 2.3911161 },
  "plusCode": "6FR4995R+7CQ",
  "lote": { "class": "residential", "coverage": "official-street", "enclosed": false, "floorAreaM2": 280.6, "kind": "building", "official": "Rue 12.202, Cotonou", "rule": "single", "structures": 1, "use": "residential" },
  "credit": "N-Ways Addressing for Benin, © N-WAYS LIMITED (nways.ng)",
  "creditUrl": "https://github.com/n-ways/open-addresses-benin"
}

Errors: 400 homecode_format when the text isn’t a code; 404 homecode_unknown with a message saying why (a name no area has, a number in no block of its name, a commune that contradicts the code).

What’s the code here?

GET https://map.nways.ng/v1/homecodes/at?lat=…&lng=… answers for a point: "status": "found" with the code, or "none" where no compound has one yet.

curl "https://map.nways.ng/v1/homecodes/at?lat=6.35822&lng=2.39112"

Search

A code typed into N-Ways search, in any of its forms, finds the compound’s gate as the first result, with "category": "homecode" and the credit in attribution.

Decode offline

The repository’s reference engine (Python, standard library only) decodes every form, checks the machine form and reads and writes spot codes, with no network: python3 engine/reference/bj_engine.py find "Cadjéhoun 18 07". Its conformance vectors (engine/reference/vectors.json) are the test for your own implementation, engine/data/register.json holds every area and name with its frozen blocks, and registry/ every issued code, one gzip file per commune.

Host it yourself

You can serve Benin’s codes from your own servers, with no calls to N-Ways. The repository on GitHub holds every issued code (registry/), the code areas and the model (model/), the reference engine, and a ready-made registry server with its JSON API:

git clone https://github.com/n-ways/open-addresses-benin
cd open-addresses-benin/server
docker compose up -d

The server imports the registry on first start, then answers lookups and searches on your machine; server/README.md covers configuration, backups and updates, and docs/api.md every endpoint. Your copy is read-only: new codes come from one issuer per country, N-Ways unless the State designates another, so no number is ever given twice. Pull the repository again for the codes issued since.

The full terms, and the credit line for maps and datasets made from the data (it also names OpenStreetMap), are in LICENSING.md. You may say your product uses N-Ways Addressing, not that it is N-Ways or is endorsed by N-Ways.