API Documentation — PropData Real Estate API

Overview

PropData is a real estate market intelligence API that aggregates 9 data sources into a single REST endpoint. One call returns rent trends, market velocity, affordability metrics, macroeconomic data, and AI-computed investor signals for any ZIP code, state, or metro in the US.

Free tier available. 50 requests/hour, no credit card required. Get your API key →

What you get in one call

Rent data — Zillow ZORI median asking rent, YoY/MoM trends, HUD Fair Market Rents by bedroom (Studio–4BR), Census median gross rent
Market data — Realtor.com days on market, active listings, price/sqft, new listings; Redfin sale-to-list ratio, % above list, homes sold
Affordability — Census ACS vacancy rate, renter %, median household income, rent-to-income ratio
Macro data — FRED live 30yr mortgage rate, shelter CPI, national vacancy, housing starts
Investor signals — 8 computed signals including gross yield, rent growth, market velocity, vacancy pressure

Authentication

All requests require an API key. Pass it as a header or query parameter.

Header (recommended)

x-api-key: YOUR_API_KEY

Query parameter

GET /v1/market?zip=55104&api_key=YOUR_API_KEY

Keep your key private. Don't expose it in client-side JavaScript. Use environment variables or a backend proxy for production apps.

Get your API key at propdata.proptechusa.ai. Free tier activates instantly — no credit card required.

Rate Limits

Rate limits are enforced per API key per hour. When a limit is exceeded the API returns HTTP 429.

Tier	Requests/hour	Requests/min	Price
Free	50	10	$0 — no credit card
Pro	500	60	$49/mo flat
Internal	Unlimited	Unlimited	—

429 response body: {"error":"Rate limit exceeded. Tier: free. Upgrade at propdata.proptechusa.ai"}

Base URL

https://propdata-api-worker.sales-fd3.workers.dev

All endpoints are prefixed with /v1/. Requests must use HTTPS. The API runs on Cloudflare's global edge network — responses are served from the nearest data center, typically under 50ms.

CORS enabled. Cross-origin requests are allowed from any domain. Use the header-based auth in production.

/v1/market

The primary endpoint. Returns a full market profile combining all 9 data sources for a given location.

GET /v1/market Full market profile

Pass one of zip, state, or metro. Returns rent data, market velocity, affordability, macro indicators, investor signals, and 12-month history.

Parameter	Type	Description
zip	optional	5-digit US ZIP code. e.g. `55104`
state	optional	2-letter state abbreviation. e.g. `MN`
metro	optional	Metro area name. e.g. `Minneapolis`

One of zip, state, or metro is required.

              
const res = await fetch(

  'https://propdata-api-worker.sales-fd3.workers.dev/v1/market?zip=55104',

  { headers: { 'x-api-key': 'YOUR_KEY' } }

);

const data = await res.json();

console.log(data.snapshot.rent.median_asking_rent); // $1,534
            
import requests

r = requests.get(

  'https://propdata-api-worker.sales-fd3.workers.dev/v1/market',

  params={'zip':'55104'},

  headers={'x-api-key':'YOUR_KEY'}

)

data = r.json()

print(data['snapshot']['rent']['median_asking_rent'])
            
curl "https://propdata-api-worker.sales-fd3.workers.dev/v1/market?zip=55104" \

  -H "x-api-key: YOUR_KEY"

/v1/rent

Rent-focused endpoint. Returns ZORI asking rent trends + full HUD Fair Market Rents by bedroom count. Faster and lighter than /v1/market if you only need rent data.

GET /v1/rent Rent trends + HUD FMR

Parameter	Type	Description
zip	optional	5-digit ZIP code
state	optional	2-letter state code
metro	optional	Metro area name

const res = await fetch(

  'https://propdata-api-worker.sales-fd3.workers.dev/v1/rent?zip=55104',

  { headers: { 'x-api-key': 'YOUR_KEY' } }

);

// Returns: median_asking_rent, fmr_1br/2br/3br/4br, yoy_pct, history[]

Response includes

Zillow ZORI median asking rent + YoY + MoM + 12-month trend
HUD FMR: Studio, 1BR, 2BR, 3BR, 4BR for the county
Census ACS median gross rent

/v1/estimate

Proprietary rent estimate engine. Returns a low/mid/high range with confidence score and full model weight transparency. Full estimate engine docs →

GET /v1/estimate Weighted rent estimate

Parameter	Type	Description
zip	optional	5-digit ZIP code
state	optional	2-letter state code
beds	optional	Bedroom count: `0`=Studio, `1`–`4`. Default: `0`

const res = await fetch(

  'https://propdata-api-worker.sales-fd3.workers.dev/v1/estimate?zip=55104&beds=2',

  { headers: { 'x-api-key': 'YOUR_KEY' } }

);

// Returns:

// estimate.monthly_low   → $1,482

// estimate.monthly_mid   → $1,609  (the number)

// estimate.monthly_high  → $1,738

// estimate.confidence_pct → 100

// methodology.data_points → [{source, weight_pct, adjusted_rent}]

Model weights

Source	Weight	Why
Zillow ZORI	40%	Current asking rent — strongest market signal
Census ACS	25%	Actual renter-paid rent — affordability anchor
HUD FMR	20%	Government bedroom benchmark — defense-grade
Redfin cap rate	15%	Investor sanity check — implied from sale price

/v1/health

GET /v1/health API + source status

Returns uptime status for all 9 data sources. No authentication required.

curl https://propdata-api-worker.sales-fd3.workers.dev/v1/health

/v1/usage

GET /v1/usage Key usage stats

Returns current hour usage, tier, and reset time for the authenticated key.

curl https://propdata-api-worker.sales-fd3.workers.dev/v1/usage \

  -H "x-api-key: YOUR_KEY"

Response Schema

All endpoints return JSON. The /v1/market full response shape:

{
  "powered_by": "PropData API / PropTechUSA.ai",
  "location": { "zip": "55104", "state": null, "metro": null },
  "snapshot": {
    "rent": {
      "median_asking_rent": 1534.41,  // Zillow ZORI
      "rent_yoy_pct": 3.63,
      "rent_mom_pct": -0.92,
      "rent_period": "2026-02",
      "fmr_efficiency": 1220,      // Studio
      "fmr_1br": 1381, "fmr_2br": 1685, "fmr_3br": 2244, "fmr_4br": 2513,
      "census_median_gross_rent": 1159
    },
    "market": {
      "median_listing_price": 319950, "price_yoy_pct": 0.2098,
      "median_days_on_market": 37, "dom_yoy_pct": 0.5851,
      "active_listings": 40, "inventory_yoy_pct": 1.0513,
      "sale_to_list_ratio": 0.979, "homes_sold": 127,
      "price_per_sqft": 207, "median_sqft": 1688
    },
    "affordability": {
      "vacancy_rate_pct": 8.69, "renter_pct": 46.08,
      "median_hh_income": 75038, "rent_to_income_ratio": 18.5
    },
    "signals": [{ "key": "gross_yield", "label": "Est. Gross Yield", "value": "5.75%", "sentiment": "neutral" }]
  },
  "macro": { "mortgage_rate_30yr": 6.38, "shelter_inflation_yoy": 0.23, "housing_starts": 1487 },
  "history": { "rent_trend": [...], "market_trend": [...] },
  "sources": { "rent_index": "Zillow ZORI", "fmr": "HUD Fair Market Rents", "macro": "FRED / St. Louis Fed" },
  "generated_at": "2026-03-29T22:46:57Z"
}

Error Codes

Code	Status	Meaning
400	Bad Request	Missing required parameter (zip, state, or metro)
401	Unauthorized	Missing or invalid API key
404	Not Found	Endpoint does not exist
429	Too Many Requests	Rate limit exceeded for your tier. Retry after the hour resets.
500	Server Error	Internal error — contact support if persistent

All errors return a JSON body: {"error": "message"}

Coverage

Data availability varies by source and geography. Dense metro ZIPs return all sources. Rural ZIPs return Census ACS, HUD FMR, and FRED macro — which are national/county-level datasets.

Source	ZIP	State	Metro
Zillow ZORI	~30K ZIPs	✓	✓
HUD Fair Market Rents	County fallback	✓	✓
Realtor.com	Active markets	✓	✓
Redfin	Active markets	✓	✓
Census ACS	33K+ ZIPs	✓	—
FHFA HPI	—	✓	✓
FRED Macro	National	National	National

Data Sources

Zillow ZORI — Zillow Observed Rent Index. Monthly median asking rent at ZIP, state, and metro level.
HUD Fair Market Rents — Annual bedroom-level rent benchmarks for every US county. Used for Section 8 vouchers.
Realtor.com Research — Monthly ZIP/state/metro listing data: DOM, inventory, list price, price/sqft.
Redfin — Sale-to-list ratio, % above list, homes sold, months of supply at ZIP level.
US Census ACS — 5-year American Community Survey. Vacancy rate, renter %, median income, rent-to-income.
FHFA HPI — Federal Housing Finance Agency quarterly Home Price Index. State and metro appreciation.
FRED / St. Louis Fed — Live 30yr mortgage rate, shelter CPI YoY, national vacancy rate, housing starts.

All data is ingested and normalized. PropData does not make real-time calls to third-party APIs on each request. Data is cached at Cloudflare edge for fast, reliable responses.