Zillow API for real estate investors

The job

The workflow

1. Collect the candidates. Paste Zillow links from saved searches and emails, or addresses from any list, into one column. Links are the most precise; addresses are matched to a Zillow property first.
2. Batch the lookups. Send up to 50 items per batch request. Each result has its own ok flag, so a bad address only drops its own row.
3. Screen on calculated fields. data.calculated has gross yield from the rent Zestimate, price versus Zestimate, the number of price drops in the current listing and days on market. They are plain arithmetic on the returned fields, and null when an input is missing.
4. Underwrite the short list. Take the homes that pass into your own model with real rent comps, repair estimates, taxes and financing. The screen tells you where to look, not what to pay.

Rank a deal list by gross yield and price cuts

Reads deals.txt (one link or address per line), batches the lookups and prints the homes that clear your thresholds. Change the thresholds to your own buy box.

import os, requests

BASE = "https://api.propertiesapi.com/v1"
HEADERS = {"x-api-key": os.environ["PROPERTIESAPI_KEY"]}
MIN_YIELD, MIN_DROPS = 7.0, 1          # your buy box

inputs = [l.strip() for l in open("deals.txt") if l.strip()]
homes = []
for i in range(0, len(inputs), 50):
    r = requests.post(f"{BASE}/zillow/batch", json={"items": inputs[i:i + 50]}, headers=HEADERS, timeout=320)
    r.raise_for_status()
    homes += [item["data"] for item in r.json()["data"] if item["ok"]]

def keep(h):
    c = h["calculated"]
    return (c["gross_yield_pct"] or 0) >= MIN_YIELD or (c["price_drops_count"] or 0) >= MIN_DROPS

for h in sorted(filter(keep, homes), key=lambda h: h["calculated"]["gross_yield_pct"] or 0, reverse=True):
    c = h["calculated"]
    print(f'{h["address"]}: ask {h["price"]}, rent est {h["rentZestimate"]}, '
          f'yield {c["gross_yield_pct"]}% ({c["rent_to_price_basis"]}), '
          f'drops {c["price_drops_count"]}, on market {c["days_on_market"]} days')

Fields that matter here

What it won't do

• It doesn't find deals for you. There is no search by area, price or criteria; you bring the links or addresses.
• It doesn't return comps. For comparables, pick the homes yourself and look each one up.
• Zestimate and rent Zestimate are Zillow's estimates, returned when Zillow shows them. PropertiesAPI has no valuation model of its own.
• No owner names, mortgage data or skip tracing.

Read next

• Rental comparison spreadsheet
• Price history guide
• Google Sheets formulas
• Calculated fields

Real estate investors: questions