Cook County / Chicago Property Data (free tier, no wallet needed)

FREE ($0, unlimited, no payment, no wallet): a fixed, representative example of every response shape this server returns for Cook County / Chicago property data — address search, parcel, dossier (recorded sales, building permits, assessment history) and comparable sales. Call this FIRST to validate the data structure before anything else. For REAL verified data at $0, call get_cook_county_property_dossier with one of the always-free example PINs 09253060510000, 09253140190000, 09253050270000.

{
  "type": "object",
  "properties": {},
  "title": "get_free_sampleArguments"
}

ALWAYS FREE, unlimited, no wallet and no signup. Resolve a Cook County / Chicago street address (full or partial) to its parcel PIN(s) — ranked candidates with address, city, ZIP, a match score and a match_quality flag. A trailing city/state/ZIP is fine ('1 E 113th St, Chicago, IL 60628'). CHECK match_quality: 'exact' is certain, 'likely' shares the house number, and 'weak' means NO candidate matched the house number — do not rely on a weak hit. Call this FIRST when you have an address but not a PIN, then pass a returned pin to get_cook_county_parcel / get_cook_county_property_dossier / find_chicago_comparable_sales. Coverage: Cook County, Illinois — Chicago plus 100+ suburbs including Evanston, Oak Park, Cicero and Skokie.

{
  "type": "object",
  "properties": {
    "address": {
      "description": "Full or partial Cook County / Chicago street address, e.g. '1 E 113th St'. Minimum 4 characters.",
      "minLength": 4,
      "title": "Address",
      "type": "string"
    }
  },
  "required": [
    "address"
  ],
  "title": "search_chicago_property_by_addressArguments"
}

FREE for your first 25 calls each day — no wallet, no signup, just call it ($0.01 per call via x402/USDC only after that daily allowance, which resets at 00:00 UTC). Cook County, IL parcel record for a 10- or 14-digit PIN. Returns: pin, prop_address, prop_city, prop_zip, class, township_name, nbhd_code, municipality, ward, police_district, census_tract_geoid, school_elementary_district, school_secondary_district, walk_score_cmap, airport_noise_dnl, lat, lon, tax_year. The cheap single-property lookup — use get_cook_county_property_dossier for sales, permits and assessments.

{
  "type": "object",
  "properties": {
    "pin": {
      "description": "10- or 14-digit Cook County PIN (digits; dashes allowed, e.g. 14-08-120-017-0000). If you only have a street address, call search_chicago_property_by_address first.",
      "pattern": "^[0-9][0-9\\-]{8,19}$",
      "title": "Pin",
      "type": "string"
    }
  },
  "required": [
    "pin"
  ],
  "title": "get_cook_county_parcelArguments"
}

FREE for your first 25 calls each day — no wallet, no signup, just call it ($0.03 per call via x402/USDC only after that daily allowance, which resets at 00:00 UTC). Full Cook County / Chicago property dossier for a PIN: parcel basics, recorded sales & deed history, building permits, property-tax assessment history, and neighborhood / ward / school / walkability context — the one-call due-diligence record. Permits are LINKED to the PIN here (the raw permit open-data has no PIN; links are derived by address + geo match), so this is a finished record you cannot reproduce with raw open-data queries. Note assessment values are ASSESSED values (~10% of market for most residential classes), not market prices — see assessment_note in the response.

{
  "type": "object",
  "properties": {
    "pin": {
      "description": "10- or 14-digit Cook County PIN (digits; dashes allowed, e.g. 14-08-120-017-0000). If you only have a street address, call search_chicago_property_by_address first.",
      "pattern": "^[0-9][0-9\\-]{8,19}$",
      "title": "Pin",
      "type": "string"
    }
  },
  "required": [
    "pin"
  ],
  "title": "get_cook_county_property_dossierArguments"
}

FREE for your first 25 calls each day — no wallet, no signup, just call it ($0.10 per call via x402/USDC only after that daily allowance, which resets at 00:00 UTC). Recent arm's-length comparable sales (comps) in the same Cook County assessor neighborhood and property class as the given PIN, each with its distance in metres from the subject, plus an implied low/median/high price range — a derived, lightweight automated valuation (AVM) you won't get from a raw open-data query. Thin markets widen automatically and the response reports which matching rung was used. Comps are NOT normalized for building size or age.

{
  "type": "object",
  "properties": {
    "pin": {
      "description": "10- or 14-digit Cook County PIN (digits; dashes allowed, e.g. 14-08-120-017-0000). If you only have a street address, call search_chicago_property_by_address first.",
      "pattern": "^[0-9][0-9\\-]{8,19}$",
      "title": "Pin",
      "type": "string"
    }
  },
  "required": [
    "pin"
  ],
  "title": "find_chicago_comparable_salesArguments"
}