Use case
Zillow data for AI agents
19 tools over MCP — listings by place, the record for any zpid and its parts, Zestimate with ten years of history, comparable homes, the listing agent, market statistics, rental buildings and mortgage rates. No account and no API key: an agent pays per call in USDC on Base, and a call that fails is not charged. Listed in the official MCP registry as dev.housedata/zillow.
claude mcp add --transport http housedata https://mcp.housedata.dev/mcp{
"mcpServers": {
"housedata": {
"url": "https://mcp.housedata.dev/mcp"
}
}
}How a paid call works
- The agent calls a tool. With no payment attached, the answer is a quote: the price, the asset and the address.
- An x402-aware client signs a USDC transfer authorisation for that amount and retries the call with it attached.
- The server verifies the authorisation, runs the tool, and settles the payment only if the tool returned data.
{
"x402Version": 2,
"error": "PAYMENT_REQUIRED",
"accepts": [
{
"scheme": "exact",
"network": "eip155:8453",
"amount": "10000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"payTo": "0x92D8…"
}
]
}Compact by default
A record comes back as its headline, ~0.7 KB; a search page as its rows. Pass expand: true for the complete response — a full record is ~17 KB — at the same price.
Prices
$0.005–$0.02 per call, per tool. The table on the home page is generated from the same catalog the server bills from.
Wallets
Any wallet holding USDC on Base can pay; the payer needs no ETH, the facilitator covers gas. The reference client is withX402Client from the Cloudflare Agents SDK.
Limits
One paid call at a time per session, and a session that keeps failing to settle is closed. Sessions expire after four hours idle; reconnecting is free.
Start with a zpid
Most tools take a zpid — the number before _zpid in a Zillow URL, or the zpid on every zillow_search_listings row. Places are typed as on Zillow: Austin, TX, 78704, a neighborhood.
Not charged
A 404 for a zpid or a place Zillow does not know is an answer from the data API and costs nothing. A 502 or 503 is retried once on our side before it is reported, also uncharged.