Developer platform API v1 Preview

NYC property data, with evidence built into the response.

Search published parcels, retrieve normalized records, and preserve the source trail. Every response identifies its revision, coverage, warnings, and provenance.

The API is in preview. We are still reviewing each source's terms for delivery through an API, so responses return parcel identifiers and coverage, and mark every other field withheld until that review is done. A search that returns parcels counts toward your monthly allowance; a property response with every field withheld does not.

Get an API key Read the quickstart OpenAPI 3.1 TypeScript client Python client Ruby client Elixir client

Start here

Make your first request

Create a test key, keep it in an environment variable, and search by street address, BBL, or LotContext property ID. Search responses are never presented as proof that a record does or does not exist outside published coverage.

curl --get "https://lotcontext.com/api/v1/properties" \
  --data-urlencode "query=100 Broadway" \
  --data-urlencode "limit=5" \
  --header "Authorization: Bearer $LOTCONTEXT_API_KEY"

const url = new URL("https://lotcontext.com/api/v1/properties");
url.search = new URLSearchParams({ query: "100 Broadway", limit: "5" });

const response = await fetch(url, {
  headers: { Authorization: `Bearer ${process.env.LOTCONTEXT_API_KEY}` }
});

const payload = await response.json();

import os
import requests

response = requests.get(
    "https://lotcontext.com/api/v1/properties",
    params={"query": "100 Broadway", "limit": 5},
    headers={"Authorization": f"Bearer {os.environ['LOTCONTEXT_API_KEY']}"},
    timeout=15,
)
payload = response.json()

response =
  Req.get!("https://lotcontext.com/api/v1/properties",
    params: [query: "100 Broadway", limit: 5],
    auth: {:bearer, System.fetch_env!("LOTCONTEXT_API_KEY")}
  )

payload = response.body

require "net/http"
require "json"

uri = URI("https://lotcontext.com/api/v1/properties")
uri.query = URI.encode_www_form(query: "100 Broadway", limit: 5)
request = Net::HTTP::Get.new(uri)
request["Authorization"] = "Bearer #{ENV.fetch("LOTCONTEXT_API_KEY")}"

response = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |http| http.request(request) }
payload = JSON.parse(response.body)

POSTyour HTTPS endpoint Available

Signed change webhooks

Configure endpoints in the developer console. LotContext signs the exact body, sends a stable delivery ID as Idempotency-Key, retries failed deliveries with exponential backoff, and keeps a replayable delivery log.

X-LotContext-Signature

t=unix_seconds,v1=hex_hmac. Compute HMAC-SHA256 over timestamp.body with the signing secret.

Idempotency-Key

Persist this value before side effects. Replays retain the same key.

property.changedpermit.publishedapplication.publishedviolation.status_changeddocument.recorded

Security

Authentication

Create keys in the developer console and send one as Authorization: Bearer lc_…. A key is shown once; LotContext stores only its hash. Use environment variables in applications and never place keys in URLs or source control.

lc_test_…

Test mode. Reads the same published data and shares the monthly allowance.

lc_live_…

Live mode. Successful responses that deliver data use one unit.

Immediate revocation

Revoked or expired keys stop authenticating immediately.

GET /api/v1/properties Available

Search properties

Returns published parcels matching the query and filters. Results contain compact parcel summaries; use the returned id with the detail endpoint for the complete evidence-backed dossier.

Query parameters

querystring: Street address, 10-digit BBL, or LotContext property ID. Minimum 3 characters.
cursorstring: Opaque continuation cursor from meta.next_cursor. A cursor is bound to its filters and publication revision.
limitinteger: Maximum results to return. Defaults to 400 and is capped at 400.
boroughinteger: NYC borough code, 1 through 5. Optional.
formatenum: json (default) returns the standard envelope. geojson returns a GeoJSON FeatureCollection with the same revision and warnings metadata.

Response contract

data[]

Matched parcels and normalized summary fields.

meta

Request ID, API version, result count, and applied limit.

warnings[]

Coverage, licensing, staleness, or fixture qualifications.

links

Stable paths to the property dossier and related collections.

Test console

GET /properties

Endpoint Test API key query limit format

Use a test key. It is sent only to this LotContext origin and is never stored.

Response

Ready

{
  "data": {
    "bbl": "3999900001",
    "block": 99990,
    "borough": {
      "code": 3,
      "name": "Brooklyn"
    },
    "coverage": [
      {
        "section": "parcel",
        "status": "available"
      },
      {
        "section": "violations",
        "status": "not_covered"
      }
    ],
    "facts": [
      {
        "evidence": {
          "dataset_id": "64uk-42ks",
          "publication_revision": "1",
          "record_key": "3999900001",
          "source_fields": [
            "lotarea"
          ],
          "source_id": "dcp_pluto",
          "source_release": "26v2"
        },
        "field": "lot_area_sqft",
        "label": "Lot area",
        "status": "available",
        "unit": "sq_ft",
        "value": 22500
      }
    ],
    "id": "lc_prop_9c49b74aa8e340b0bf547d41eda700f5",
    "lot": 1,
    "subject": {
      "parcel_id": "lc_parcel_…",
      "type": "parcel"
    },
    "synthetic": true
  },
  "meta": {
    "api_version": "v1",
    "coverage_status": "partial",
    "data_revision": "1",
    "environment": "test",
    "request_id": "F1a2…"
  },
  "warnings": [
    {
      "code": "synthetic_fixture_data"
    },
    {
      "code": "section_not_covered"
    }
  ]
}

Request history This page only

No requests sent yet.

Synthetic example — a trimmed test fixture, not a real property.

GET /api/v1/changes Available

Publication change feed

Consume committed canonical changes in revision order with a key carrying changes:read. Save meta.next_cursor after processing a page, then send it back to continue or poll. Filter by property, resource type, or change type without exposing collector endpoints or provider health.

revision

Monotonic publication boundary.

fields[]

Normalized fields changed in this publication.

publication

Source, release, and publish time.

Reference

Endpoint index

Method	Path	Returns	Status
GET	/properties?query={address-or-BBL}	Published parcel matches	Available
GET	/properties/{id}	Complete property dossier	Available
GET	/properties/{id}/violations	Normalized violation records	Available
GET	/properties/{id}/permits	Normalized permit records	Available
GET	/properties/{id}/applications	Normalized application records	Available
GET	/properties/{id}/transactions	Recorded-document summaries	Available
GET	/properties/{id}/timeline	Chronological activity	Available
GET	/properties/{id}/reported-ownership	Source-qualified parties	Available
GET	/changes	Committed canonical publication changes	Available
GET	/meta/coverage	Published corpus coverage and freshness	Available

API lifecycle

Changelog

September 22, 2026 · v1
Webhook delivery and coverage metadata
Added signed idempotent webhooks, delivery logs and replay, /meta/coverage, GeoJSON search output, and Ruby/Elixir clients.
September 20, 2026 · v1
Initial public contract
Published property search, dossier sections, revision-bound cursors, change feed, conditional requests, test keys, and OpenAPI 3.1.

Data semantics

Coverage is part of the payload

A null never stands in for “no records.” Each dossier section reports an explicit state so an unavailable source cannot be confused with a completed search that found nothing.

availableno_matching_recordsnot_coveredstaleconflictingtemporarily_unavailablewithheld

Fields awaiting API-delivery rights use status: "withheld" with a source_rights_pending warning. Those responses are not billed.

Decimals are strings, areas carry explicit units, timestamps are ISO 8601 UTC, and meta.data_revision identifies the publication reflected by the response.

Successful responses include ETag, X-Data-Revision, and rate-limit headers. Send If-None-Match to receive an unbilled 304 when the publication is unchanged.

Failure modes

Errors

Every error uses the same envelope: {"error": {"code": …, "message": …, "request_id": …}}. Include the request ID when contacting support.

400: invalid_request; A parameter is malformed or outside its supported range.
401: invalid_credentials; The key is missing, malformed, revoked, or expired.
404: not_found; No published property has that identifier.
429: quota_exceeded; The monthly allowance or per-minute rate limit was reached.

Usage

Allowances

Every account starts on Free. Paid tiers are not yet on sale; these are draft limits for testing and may change before launch. Limits are hard caps, with no surprise overage charges.

Tier	Monthly units	Active keys	Availability
Free	100	2	Available
Developer	5,000	5	Draft
Pro	50,000	10	Draft
Business	200,000	25	Draft