Slum Area Check API: is this plot in a mapped slum area?

Example

Request

curl -X POST https://verified.realestate/api/v1/tools/slum_area_check \
  -H "Authorization: Bearer $LANDLENS_KEY" \
  -H "Content-Type: application/json" \
  -d '{"mode":"check","lat":12.901,"lng":80.2279}'

Responsereal answer

{
  "ok": true,
  "status": "ok",
  "data": {
    "found": true,
    "mode": "check",
    "status": "not_mapped",
    "in_mapped_slum": false,
    "verdict": "No mapped slum boundary here",
    "message": "No slum boundary on the state GIS slum map meets this location in Chennai. The map is not the notified list, so this is not a clearance.",
    "basis": "point",
    "basis_note": null,
    "corporation": "Chennai",
    "hits": [],
    "hit_count": 0,
    "nearest": {"slum_name": "Solingahanallur-Grama Nedunsalai", "ward": "197", "zone": "15", "corporation": "Chennai", "lat": 12.900958, "lng": 80.232133, "distance_m": 459.4},
    "nearby_other_count": 1,
    "near_radius_m": 500,
    "covered_cities": ["Chennai", "Coimbatore", "Erode", "Madurai", "Tiruppur"],
    "map_areas": 2183,
    "map_fetched_at": "2026-09-14T12:09:26+00:00",
    "caveat": "This reads the state GIS slum boundary map. It is not the list of areas notified under the Tamil Nadu Slum Areas (Improvement and Clearance) Act, 1971, and it covers only the Chennai, Madurai, Coimbatore, Tiruppur and Erode corporations. Confirm any finding with the Tamil Nadu Urban Habitat Development Board and the corporation."
  },
  "credits_charged": 0
}

A real answer from the API for a point in Sholinganallur, Chennai, with the echoed point, source and page link left out.

What it returns

One call. Read status: mapped_slum, not_mapped or not_assessed.

Field	What it holds
`status, verdict, in_mapped_slum`	mapped_slum ("Inside a mapped slum boundary"), not_mapped ("No mapped slum boundary here", never "clear"), or not_assessed (outside the five corporations).
`message, caveat`	The answer in words, and what the map is and is not.
`basis, basis_note`	Whether the parcel boundary or the point was read, and why a boundary was set aside.
`hits[]`	Each mapped slum area the location meets: slum_name, slum_code, ward, zone, corporation, area_sqm, centre and relation (how the location meets it, e.g. inside).
`nearest, nearby_other_count, near_radius_m`	The nearest mapped area with its distance, and how many others lie within 500 m.
`corporation, covered_cities, map_areas, map_fetched_at`	Which corporation the location is in, the five covered, how many areas the map holds and when it was read.
`list mode: areas[]`	The mapped slum areas of a corporation, zone or ward, a page at a time, with the corporation's totals.

Inputs

The JSON body of the POST is the arguments. For a plot send mode check with lat and lng; for a ward send mode list with city, and ward or zone.

Argument	Type	What to send
`mode`required	string: check, list	check (a location) or list (a corporation, zone or ward).
`lat`	number	For check: latitude in decimal degrees.
`lng`	number	For check: longitude in decimal degrees.
`parcel_geojson`	string	For check: the parcel boundary as a GeoJSON Polygon or MultiPolygon, as resolve_parcel returns it. Send lat and lng too.
`parcel_extent_sqm`	number	For check with a boundary: the recorded extent in square metres, so a boundary that is not the plot can be caught.
`city`	string: Chennai, Madurai, Coimbatore, Tiruppur, Erode	For list: Chennai, Coimbatore, Erode, Madurai or Tiruppur.
`zone`	string	For list, Chennai only: the zone number, 1 to 15.
`ward`	string	For list, Chennai only: the ward number, 1 to 200.
`limit`	integer	For list: how many areas to return, default 50, at most 200.
`page`	integer	For list: which page of that size, default 1. The answer says when more areas follow.

Code

Set LANDLENS_KEY to your key. In an AI app, connect https://verified.realestate/mcp once and ask in plain words instead. In Postman, download this API's collection, import it (File, Import) and set apiKey.

curl -X POST https://verified.realestate/api/v1/tools/slum_area_check \
  -H "Authorization: Bearer $LANDLENS_KEY" \
  -H "Content-Type: application/json" \
  -d '{"mode":"check","lat":12.901,"lng":80.2279}'

import os, requests

r = requests.post(
    "https://verified.realestate/api/v1/tools/slum_area_check",
    headers={"Authorization": f"Bearer {os.environ['LANDLENS_KEY']}"},
    json={
        "mode": "check",
        "lat": 12.901,
        "lng": 80.2279
    },
    timeout=20,
)
body = r.json()
print(body["status"], body["credits_charged"], body["data"])

const res = await fetch("https://verified.realestate/api/v1/tools/slum_area_check", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.LANDLENS_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "mode": "check",
    "lat": 12.901,
    "lng": 80.2279
  }),
});
const body = await res.json();
console.log(body.status, body.credits_charged, body.data);

Is my plot at 12.9010, 80.2279 in Chennai inside a slum area? How far is the nearest one?

Your AI reads the slum boundary map at the point and gives the caveat with the answer. It is free.

Responses

Every answer has the same envelope. What status can say for this call:

status	What it means
`ok`	The location was read (mapped_slum or not_mapped), or a list came back.
`not_found`	The location is outside the five corporations (not_assessed), the input could not be read, an empty list, or the map could not be read. Nothing is concluded.
`invalid_args`	mode was missing. Nothing ran.
`free_limit_reached`	The account has used its free calls for the hour or the day. retry_after says how many seconds to wait; paid calls keep working.

Where the data comes from

Register

The slum boundary map published on the Tamil Nadu GIS portal. It is not the list of areas notified under section 3 of the Tamil Nadu Slum Areas (Improvement and Clearance) Act, 1971.

Coverage

Chennai 1,195 areas, Coimbatore 397, Madurai 350, Tiruppur 92 and Erode 88, plus 61 just outside the corporation limits. Only the Chennai areas carry a name, ward and zone. Anywhere else in Tamil Nadu the answer is not assessed.

How current

The map carries no date of its own. Our copy was read on 14 September 2026 and is reviewed every six months; map_fetched_at in each answer gives the date.

How we read it

A parcel boundary is tested against the slum polygons, and a point when no boundary is sent. A boundary that is plainly not the plot (village sized, or far larger than its recorded extent) is set aside and the point is read instead, and basis_note says why.

Who uses it

Buyers

Check whether a plot in a covered city falls inside a mapped slum boundary before buying, and confirm with the board if it does.

Lenders

Flag properties that meet a mapped slum boundary for a closer look at title and approvals.

Researchers and NGOs

List the mapped slum areas of a Chennai ward or zone with their extents.

Limits and good practice

The map is not the list notified under the Slum Areas Act. A mapped area may not be notified, and a notified area may not be mapped.
not_mapped is "no mapped slum boundary here", never a clearance.
Only Chennai, Madurai, Coimbatore, Tiruppur and Erode are covered. Elsewhere the answer is not assessed.
Names, wards and zones exist only for Chennai. Other corporations' areas come back without names.
The map carries no date of its own.

Pricing

Free

The slum area check costs nothing. Free calls have their own allowance per hour and per day, counted across every key and connected app on the account. Credits come from the same LandLens wallet as the chat and the minis. How billing works.

Calling at volume?

Free calls have an hourly and daily allowance. For more than that, or a platform built on these registers, we set up limits and a plan to match.

WhatsApp 99961 29996

Questions

Is there an API to check whether a plot is in a slum area in Chennai?

Yes. Send mode check with the plot's latitude and longitude. The answer says whether it meets a mapped slum boundary, names the area, and gives the nearest one.

Is a mapped slum area the same as a notified slum?

No. This is the state GIS slum boundary map, not the list notified under the 1971 Act. Confirm any finding with the Tamil Nadu Urban Habitat Development Board and the corporation.

Can I list the slum areas in a Chennai ward?

Yes. Send mode list, city Chennai and the ward number.

How much does it cost?

It costs nothing, within the account's free call allowance.