API Documentation

Integrate proprietary real estate intelligence directly into your models and CRMs.

Authentication

All API requests require an API key passed via the x-api-key header or as a query parameter ?apiKey=.

curl -H "x-api-key: YOUR_KEY" https://addressintel.co/api/v1/market-signals
Download OpenAPI Spec (JSON)Perfect for integrating with OpenAI Function Calling or LangChain.

Endpoints

GET/api/v1/market-signals

Retrieves top investment opportunities scored by our proprietary engine. For the Peninsula, properties are scored on teardown potential. For Nantucket, properties are scored on flippability and historic charm.

Query Parameters

  • market(Optional) Filter by market ("peninsula" or "nantucket"). Defaults to peninsula.
  • city(Optional) Filter by city name (e.g., "Atherton")
  • address(Optional) Search for a specific address

Response

{
  "success": true,
  "count": 25,
  "data": [
    {
      "id": "abc-123",
      "address": "123 Main St",
      "city": "Menlo Park",
      "price": 2400000,
      "status": "Active",
      "teardownScore": 95.5,
      "flippabilityScore": 0,
      "developerROI": 32.1,
      "conditionScore": 3.5,
      "visionAnalysis": "...",
      "metadata": {
        "sqft": 1100,
        "lotSize": 14500,
        "daysOnMarket": 4
      }
    }
  ],
  "pagination": {
    "limit": 25,
    "offset": 0,
    "total": 480,
    "returned": 25,
    "nextOffset": 25
  },
  "asOf": "2026-06-20T15:30:00.000Z"
}

Interactive Playground

Test the API directly from your browser. Click the button below to fetch live data using a demo API key.

GET/api/v1/market-signals?apiKey=demo

Click "Run Request" to see a live demo of the API response.

Using the demo API key restricts results to 2 items.

GET/api/v1/properties/:idFree Tier

Retrieves detailed intelligence for a single property, including aggregated comp data and proprietary scores.

Path Parameters

  • idThe unique identifier of the property

Response

{
  "success": true,
  "data": {
    "id": "abc-123",
    "address": "123 Main St",
    "city": "Menlo Park",
    "price": 2400000,
    "intelligence": {
      "teardownScore": 95.5,
      "flippabilityScore": 0,
      "marketHeatIndex": 82,
      "biddingWarPredictor": 65
    },
    "comparables": {
      "recentSalesCount": 5,
      "avgPricePerSqft": 1250
    }
  }
}

Usage & Limits

Limits are enforced per API key based on your plan. Exceeding your rate limit returns a 429.

Demo

  • Up to 5 results per request
  • 10 requests / minute
  • No webhooks

Free

Self-serve
  • Up to 25 results per request
  • 30 requests / minute
  • No webhooks

Pro

  • Up to 500 results per request
  • 120 requests / minute
  • Real-time webhooks

Pagination

Use the limit and offset query parameters to page through results. Every list response includes a pagination object with total and a nextOffset (null on the last page), plus an asOf timestamp indicating data freshness.

Rate Limit Headers

Every response carries X-RateLimit-Limit and X-RateLimit-Remaining headers. When you exceed your plan's per-minute limit the API responds with 429.

Error Handling

Errors use standard HTTP status codes and a consistent JSON envelope: success: false, a human-readable error message, and a stable machine-readable code.

{
  "success": false,
  "error": "Unauthorized. Missing API Key.",
  "code": "unauthorized"
}

Real-time Webhooks

Pro

Push real estate intelligence directly into your CRM or internal systems. Subscribe to webhook events to receive real-time notifications when major construction or demolition permits are filed. Webhook registration requires a Pro API key.

Subscribing to Webhooks

You can register your webhook endpoint via the API or using the form below.

Register via UI
Register via API
curl -X POST https://addressintel.co/api/v1/webhooks/register \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://your-domain.com/webhook"}'

Supported Events

  • permit.created - Fired when a new high-value permit is recorded
  • property.score_updated - Fired when a property's teardown or flippability score changes

Example Payloads

{
  "event": "permit.created",
  "market": "sf-peninsula",
  "data": {
    "permitId": "B24-1052",
    "type": "Demolition",
    "address": "123 Main St, Menlo Park",
    "estimatedValue": 150000,
    "status": "Issued"
  },
  "timestamp": "2026-06-12T15:30:00Z"
}

Verifying Signatures

Every delivery is signed. Compute an HMAC-SHA256 of the raw request body using the signingSecret returned at registration, and compare it (constant-time) against the X-AddressIntel-Signatureheader. Reject any request that doesn't match.

import crypto from "crypto";

// `secret` is the signingSecret returned when you registered the webhook.
function verify(rawBody, signatureHeader, secret) {
  const expected = "sha256=" + crypto
    .createHmac("sha256", secret)
    .update(rawBody)
    .digest("hex");
  return crypto.timingSafeEqual(
    Buffer.from(signatureHeader),
    Buffer.from(expected)
  );
}

// In your handler:
const ok = verify(rawBody, req.headers["x-addressintel-signature"], secret);
if (!ok) return res.status(401).end();

Plans & Pricing

Most builders start with Concierge — book a call and we do the deal-sourcing for you. Prefer to build on the raw data yourself? Grab a free API key or go Pro.

Free

$0/mo
  • 25 results per request
  • 30 requests / minute
  • Community support
Most Popular

Concierge

from$750/mo

Done-for-you deal sourcing · custom to your area

+ $5,000 finder's fee per closed deal

  • Curated spec/rebuild plays in your area, weekly
  • Developer ROI & teardown analysis done for you
  • Off-market & new-permit alerts
  • Direct line — work 1:1 with the founder
  • Full Pro data access included
  • You only pay the finder's fee when you close
Book a Call

Pro API

$249/mo
  • 500 results per request
  • 120 requests / minute
  • Real-time webhooks
  • Priority support

Enter your email for Free or Pro API. Concierge is set up over a quick call.

Build on Silicon Valley real estate intelligence

The AddressIntel API exposes the same proprietary data that powers our real estate investment screener and building permit tracker: teardown scores, projected developer ROI, comparable sales, and real-time permit events across the Silicon Valley Peninsula. Use it to enrich your CRM, train models, or trigger workflows the moment a high-value permit is filed.

New to how we score properties? The developer guides walk through teardown ROI, Floor Area Ratio, and the demolition permit process that underpin every value in these endpoints.

Explore the platform

See the data in action across the AddressIntel product before you integrate.

Investment Screener

The market-signals endpoint, visualized: filter properties by teardown score and developer ROI.

Building Permit Tracker

The live feed behind the permit.created webhook — demolition and renovation permits as they post.

How to Calculate Teardown ROI

Understand the residual land-value model behind the developerROI field in the API response.

Peninsula Locations Directory

See the geographic coverage available through the city and market query parameters.