Gaff Check vs Zillow MCP
A side-by-side look at the Gaff Check and Zillow MCP MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Gaff Check for real estate work as a local process; choose Zillow MCP for real estate as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Gaff Check when
- You need dedicated capabilities in the Real Estate domain.
- You prefer a local stdio subprocess transport.
- You want tools like
resolve_location, planning_applications, sold_prices.
Choose Zillow MCP when
- You need dedicated capabilities in the Real Estate domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: other.
- You want tools like
zillow_search_properties, zillow_sweep_area, zillow_get_property.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Real Estate | Real Estate |
| Quality signal | 61/100 · Good | 63/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | Not declared | other |
| Pricing | Not declared | Free |
| Required env vars | None listed | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 8 | 0 |
| Directory activity | 1 views 0 installs 0 upvotes | 1 views 0 installs 0 upvotes |
| Tools | 8 | 21 |
| Full listing | View Gaff Check | View Zillow MCP |
Tools & capabilities
Gaff Check tools 8
resolve_locationResolve a free-text Irish address or place name to geographic coordinates (WGS84 lat/lng), returning ranked candidate matches. Use this first when the user gives an address, street, townland, or place name in Ireland, to confirm the correct location before calling other gaff-check tools — every candidate echoes its full resolved name so you (and the user) can sanity-check the match. If you already have exact lat/lng coordinates, you do not need this tool. Geocoding uses OpenStreetMap Nominatim and is best-effort: rural addresses and new estates may match poorly, and Eircodes only resolve where OSM mappers happen to have added them (there is no licensed Eircode lookup — if the user has only an Eircode, ask for the address or an approximate location instead). The confidence score ranks candidates within one query; it is not an absolute probability. Coordinates are WGS84 decimal degrees.planning_applicationsFind Irish planning applications near a location, from the National Planning Application Database (all 31 local authorities, coverage back to ~2010, updated on varying cadences). Use this for property due diligence: pending or recent developments near a home (apartment blocks, roads, masts), extensions and attic conversions on the same street (precedents for what gets approved), and refusals that hint at site constraints. Returns per application: reference number, local authority, development description, address, status, decision with dates, distance in metres from the query point, and a link to the local authority's planning file where available. Provide either lat/lng (WGS84) or a free-text address (geocoded via OpenStreetMap; the resolved location is echoed back — verify it matches before drawing conclusions). Dates are ISO YYYY-MM-DD. The 'decided'/'pending' filter is based on whether a decision date is recorded; raw status strings vary by local authority and are returned verbatim. Coordinates of some older applications are approximate, and update lag differs by authority — absence of results is not evidence that nothing is planned.sold_pricesLook up actual sold prices of residential properties in Ireland from the official Property Price Register (PSRA), which records declared prices from stamp-duty filings since January 2010. Use this to see what properties actually sold for near a property of interest: filter by county (required — the register is organised by county), a free-text address fragment (e.g. a street or estate name), an Eircode routing key (first 3 characters, e.g. 'D06' — only present on more recent records), a date range, and/or a price range. Returns per sale: date, declared price in EUR, address as recorded, Eircode where recorded, new vs second-hand, and flags for not-full-market-price and VAT-exclusive sales. Results are newest first. Know the data's limits: addresses are free text typed from stamp-duty returns — spelling varies, many records lack Eircodes, and address matching is substring-based, so try street name alone before street + number. There is no floor area, so price-per-square-metre cannot be derived. Prices on new builds are often VAT-exclusive (flagged), and declared-price errors exist in the register. This tool reports records, not valuations. If the user has no county, ask them (or infer it from the address) before calling.radon_riskGet the EPA's radon risk classification for the area containing a location in Ireland. Radon is a naturally occurring radioactive gas and the second biggest cause of lung cancer in Ireland after smoking. Use this during property due diligence to learn the area's banding from the EPA Radon Risk Map: the result echoes the EPA's own wording ("About 1 in N homes in this area is likely to have high radon levels", where N is 5, 10 or 20 — lower N means higher risk) plus a high_radon_area flag (true for the 1-in-5 and 1-in-10 bands, the ≥10% threshold Ireland uses to designate High Radon Areas, which carry legal testing duties for workplaces). This is an area-level prediction from measurement and geological data — it is NOT a measurement of any specific home. The EPA's standing advice ships in every response: any home anywhere can have high radon regardless of banding, the only way to know is to test, and testing is cheap (~€50). Provide lat/lng (WGS84) or a free-text address (geocoded; resolved location echoed back).zoningGet the generalised land-use zoning for a location in Ireland, from the Myplan.ie composite of all current local authority development plans. Use this in property due diligence to learn what the land is zoned for — residential, agricultural, open space, industrial, mixed use, etc. Zoning tells you what could be built there (or next door), whether a site has development potential, and whether a use is likely permissible. Returns the generalised zone type (standardised across authorities, e.g. 'Existing residential'), the local authority's own original zone label and objective text, the development plan name with its validity dates, and a link to plan documents where available. Provide lat/lng (WGS84) or a free-text address (geocoded; resolved location echoed back). Important: generalised zoning is a standardised simplification that complements but does NOT replace the statutory development plan — zone boundaries are generalised, and specific objectives, conditions and designations (protected structures, flood zones, SACs) live in the written plan. Verify anything decision-critical against the local authority's plan via the link. Points on unzoned land (much of rural Ireland outside town plans) return no records; that means no zoning objective is mapped, not that development is impossible.flood_riskCheck mapped flood context for a location in Ireland: groundwater flood probability (high/medium/low), maximum historic groundwater flooding, and observed winter 2015/2016 surface-water flooding, from Geological Survey Ireland's 1:20,000 mapping. Use this in property due diligence. For each layer you get: whether the point itself lies inside a mapped extent (at_point), how many extents fall within the search radius, and the distance in metres to the nearest one. Groundwater flooding (turloughs, high water tables) is a distinct hazard from river or coastal flooding and matters especially in karst limestone areas of the west and midlands. CRITICAL LIMITATION — this tool does NOT check river (fluvial) or coastal flood models. The OPW's national flood extent datasets are licensed CC-BY-NC-ND, which forbids serving derived query results, so results include unchecked entries for them pointing to the OPW's official viewer (floodinfo.ie) where the user can view all flood maps for the location. A property can be at serious river or coastal flood risk while showing nothing in this tool's results. Never interpret empty results as "no flood risk": mapping is not exhaustive, pluvial (rain) flooding is not mapped at all, and the fluvial/coastal layers are not queried. Absence of a mapped extent means exactly that and no more. Provide lat/lng (WGS84) or a free-text address (geocoded; resolved location echoed back). Insurance decisions use different, private data — this tool says nothing about insurability.ber_contextGet Building Energy Rating (BER) context for an area of Ireland: the distribution of BER grades (A1 best … G worst) among certified dwellings in a county or Dublin postal district, optionally narrowed to a construction era, plus current SEAI retrofit grant amounts. Use this to answer "what energy rating is typical for a house of this age around here?" and "what upgrade grants exist?" during property due diligence. Data is CSO statistics aggregated from BER certificates published since 2009 — e.g. 1978-1999 houses in Co. Galway cluster around C/D, while 2015+ builds are overwhelmingly A-rated. Areas accepted: the 26 counties, the cities (Dublin/Cork/Galway/Limerick/Waterford), or Dublin postal districts ('Dublin 9', 'D6W'). Construction periods: 1700-1977, 1978-1999, 2000-2004, 2005-2009, 2010-2014, 2015-2019, 2020-2024, 2025-2029. THIS TOOL CANNOT TELL YOU A SPECIFIC HOME'S BER — never present the area distribution as the property's rating. A home's actual BER is on its certificate: the seller/agent must provide it, or it can be looked up on SEAI's public register (link included in every response) with the BER number or MPRN. Note also the statistics' bias: only dwellings that needed a certificate (sold, rented, grant-aided, or new since 2009) are counted, so old housing stock that never transacted is under-represented and its true typical rating is likely worse than shown. Grant amounts are a static reference with a last-verified date — confirm on seai.ie before financial decisions.recorded_crime_contextGet recorded-crime context for the Garda sub-district containing an Irish location, using official CSO counts and current Garda administrative boundaries. Use this for factual questions such as "what categories of crime have been recorded in this wider Garda area?" or to supply category-specific values for a choropleth. It returns annual counts, a pooled annual average, rates per 1,000 Census 2022 residents with approximate 95% Poisson intervals, and optionally the latest four-quarter Garda Division trend. Provide WGS84 lat/lng or a free-text address. Offence groups use official broad codes 03–16; omit them to return all published local groups. This is NOT a street-level crime heatmap or a property safety assessment. CSO station data applies to the entire Garda sub-district polygon: incidents have no published coordinates and may have happened anywhere within it. Never infer a hotspot near the address, spread incidents evenly across the polygon, combine categories into a score, or label the property/area safe or unsafe. Homicide (01) and sexual offences (02) are not published at this local resolution and are explicitly reported as unchecked. Resident-based rates are weak in city centres, airports, retail and nightlife areas with large non-resident populations; enforcement activity also affects some categories. Recorded incidents use PULSE report dates, can be revised, and are not a measure of all crime experienced. Fraud has a 2023 break and a narrower public-reported series from 2024.
Zillow MCP tools 21
zillow_search_propertiesSearch Zillow listings by location (city, ZIP, neighborhood, or address) and optional filters (status, price band, beds/baths minimums, home types). Returns matching properties with price, beds/baths, sqft, Zestimate, status, image, and homedetails URL. Works with city/ZIP-level queries (filtered against your criteria) AND with full-address or street-only queries (returns the listings Zillow resolves to directly — filters are not applied in this single-round-trip path; use zillow_get_by_address for the cleanest one-shot address → zpid lookup). Throws LocationNotResolved if Zillow can't pin either a region or matching listings for the input (instead of silently falling back to your default search region). Heads up: Zillow renders ~40 listings per page server-side; this tool auto-paginates by default when `limit` exceeds that, walking subsequent pages and concatenating results (set `auto_paginate: false` to opt out and get the single-page response). For dense markets, price-band the search to enumerate fully. Does NOT return Zestimate history — use zillow_get_zestimate_history for that. Read-only; safe to call repeatedly.zillow_sweep_areaEnumerate EVERY Zillow listing matching the filters inside a location (resolved like zillow_search_properties) or an explicit bounding box, without silent truncation. Splits the area into map tiles and recursively quarters any tile whose Zillow-reported total exceeds what one query can return, dedupes by zpid and re-applies the numeric filters (drift guard). Returns a completeness summary (requests, tiles, unique listings, tiles still truncated at max depth, drift warnings such as Zillow ignoring the price filter or the viewport) plus the listings, or writes the listings to `output_path` as JSON for large areas (inside the output directory: ZILLOW_OUTPUT_DIR, default ~/Downloads/zillow-mcp). Sequential requests with a delay, paced by the same per-host requests-per-minute throttle as `zillow_bulk_get`; if Zillow's bot-wall blocks a request the sweep stops and returns `{ blocked: true, retry_after_s }` with what it had. Read-only against Zillow; the only write is the optional local output file.zillow_get_propertyFetch a property's full Zillow record by zpid (numeric Zillow Property ID, e.g. 12345) or by homedetails URL. Returns address (Zillow's slugged form), mls_street_address (canonical MLS form — prefer this when it disagrees), neighborhood, price, Zestimate, rent Zestimate, beds/baths, square footage, lot_size (sq ft) plus the derived lot_size_acres (round(lot_size / 43560, 2); both null — never 0 — for condos and listings with no lot), year built, schools, and an `extracted_features` block (lake_front, hot_tub, basement, furnished, dock, community) keyword-parsed from the description. Also returns `zest_vs_list_pct` — the list-vs-Zestimate spread, `(price − zestimate) / zestimate × 100` rounded to 1 decimal: POSITIVE means listed ABOVE the Zestimate, negative below (null when either input is missing). The raw `description` is omitted by default — pass `include_description: true` to keep it; in most cases the extracted features cover what callers need. Price-history and tax-history are also opt-in (`include_price_history: true` / `include_tax_history: true`) — bundle them in to skip a separate call. Provide exactly one of zpid or url. Read-only; safe to call repeatedly.zillow_get_zestimate_historyHistorical Zestimate values for a property by zpid or homedetails URL. Returns a time series of {date, value, rent?} entries (rent included when Zillow has a rent Zestimate for the property). Note: zillow_get_property returns only the *current* Zestimate as a scalar — call this tool when you need the trend. For some listings (commonly non-Showcase) Zillow renders the trend client-side and omits it from the server-rendered page; then `points` is empty and an explanatory `note` is returned — distinct from a genuine no-history. Read-only; safe to call repeatedly.zillow_get_saved_searchesThe signed-in user's saved searches on zillow.com (name, filters, new-listing count, notification frequency). Requires the user to be signed in at zillow.com in the bridged browser tab — throws SessionNotAuthenticatedError otherwise. An optional `session_id` (from `zillow_register_session`) is checked against the session registry — an unknown id errors — but it is a label only: the request always goes through whichever browser tab the extension is signed into. Read-only; safe to call repeatedly.zillow_get_saved_homesThe signed-in user's saved (favorited) homes on zillow.com, flattened across all of the user's collections. Returns address, price, Zestimate, status, and when each home was saved. An optional `session_id` (from `zillow_register_session`) is checked against the session registry — an unknown id errors — but it is a label only: the request always goes through whichever browser tab the extension is signed into. Requires the user to be signed in. Read-only; safe to call repeatedly.zillow_get_market_reportMarket report for a Zillow region: median sale/list prices, days on market, for-sale inventory, new listings, Zillow Home Value Index (ZHVI), and year-over-year ZHVI change. Provide either a `region_path` (e.g. "/home-values/6181/brooklyn-ny/") or a full Zillow home-values URL. Read-only; safe to call repeatedly.zillow_calculate_mortgageLocal-only mortgage payment calculator. Returns a full PITI breakdown (principal + interest, property tax, insurance, HOA, PMI) and total interest over the life of the loan. No network call — fully deterministic, safe to use for scenario comparison without burning a fetch. Provide either `down_payment` OR `down_payment_percent`; defaults to 20%. Property tax can be given as `property_tax_annual` or `property_tax_rate` (% of home price). PMI applies automatically when LTV > 80% and `pmi_rate` is provided.zillow_get_price_historyListing-price events for a property — listings, price changes, pending, sold, etc. — by zpid or homedetails URL. Returns two parallel arrays: `events` (raw Zillow shape with `event` strings and MLS attribution) and `events_normalized` (cross-MCP shared shape with a fixed `type` enum: Listed/PriceChange/Pending/Contingent/Sold/Withdrawn/Relisted/Delisted). The normalized form lets callers merge histories across real-estate MCPs without re-implementing taxonomy. Sourced from the same homedetails page as zillow_get_property. For some listings (commonly non-Showcase) Zillow omits the history from the server-rendered page; then `events` is empty and an explanatory `note` is returned — distinct from a genuine no-history.zillow_get_tax_historyYear-by-year property-tax record for a property: tax paid, assessed value, and the year-over-year change rates. Sourced from the homedetails page. Useful for spotting reassessment jumps or comparing tax burdens across properties. For some listings (commonly non-Showcase) Zillow omits the history from the server-rendered page; then `events` is empty and an explanatory `note` is returned — distinct from a genuine no-history.zillow_compare_propertiesSide-by-side analysis of 2-25 Zillow properties. **If you just want N property records, use `zillow_bulk_get` instead** — compare is for genuine side-by-side (its pivoted summary table is the value-add); bulk_get is the fetch-many endpoint and accepts up to 200 ids. (Issue #79 raised this cap from 8 to 25 — a 19-listing analysis now fits in one call instead of three.) Provide an array of zpids (or homedetails URLs). Returns the full per-property record per row (with `extracted_features` populated). Pass `include_summary: true` for an extra pivoted summary table (one row per field) — defaults off because `results[].property.*` already carries everything. The raw `description` is omitted from each row by default — pass `include_description: true` to keep it. Errors for individual properties are captured per-row — one bad zpid won't fail the whole call. Calls fan out concurrently (capped at 6 in flight, per issue #78, with retry-once-on-timeout per sub-request to absorb transient SW evictions), paced by the same throttle as `zillow_bulk_get`; a bot-wall block is retried with backoff and, if it persists, reported as `error_kind: "bot_challenge"` (distinct from a missing listing) with `{ blocked, retry_after_s }` on the envelope. The call is bounded by an overall deadline — unsettled rows come back as `error_kind: "pending"`.zillow_calculate_affordabilitySolve for the maximum home price you can afford under the standard 28/36 DTI rule. Inputs: monthly income, recurring monthly debts (car loans, student loans, etc.), down payment, interest rate, and optional property-tax rate / insurance / HOA / loan term. Output: max home price, the binding constraint (front-end vs back-end), and the full PITI breakdown at that price. Same math across the realty MCP cohort (@chrischall/realty-core). No network — pure local math.- +9 more on the listing page
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Gaff Check
{
"mcpServers": {
"gaff-check": {
"command": "npx",
"args": [
"-y",
"gaff-check"
]
}
}
}
Zillow MCP
{
"mcpServers": {
"zillow-mcp": {
"command": "npx",
"args": [
"-y",
"zillow-mcp"
]
}
}
}
Frequently asked questions
Gaff Check is categorized under Real Estate and uses a local stdio subprocess. Zillow MCP belongs to Real Estate and uses a local stdio subprocess. Pick Gaff Check for real estate work and Zillow MCP for real estate.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Gaff Check has no declared pricing — check the project's own site. Zillow MCP is listed as free. Auth: other. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add gaff-check and zillow-mcp as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Gaff Check has a quality signal of 61/100 (Good) with 1 views, 0 installs and 8 GitHub stars. Zillow MCP has 63/100 (Good) with 1 views, 0 installs and 0 GitHub stars.