King County Permit Status MCP Server

King County Permit Status

Look up building permit history and status across King County, WA jurisdictions — county-level permits (septic, critical areas, grading) and city-level permits (building, mechanical, electrical) can all apply to the same address. Coverage is live where a jurisdiction offers an open permit feed, and falls back to the correct municipal portal link everywhere else.

Coverage today: 🟢 20/39 cities live (status + history) · 🟠 19/39 indexed (issued-permit history from the King County Assessor; current status needs the city portal, which next_step names) · plus unincorporated King County. See the coverage scorecard below for the per-city breakdown.

python3 lookup.py "27927 E Main St"           # by address
python3 lookup.py "7222000353"                  # by parcel number
python3 lookup.py "B25000947"                   # by permit number
python3 lookup.py "23-127651-LP"                # Bellevue permit number
python3 lookup.py "6145915-CN"                  # Seattle SDCI permit number
python3 lookup.py --pipe "27927 E Main St"      # agent pipeline mode
python3 lookup.py --limit 10 --since 2020-01-01 --type electrical "27927 E Main St"   # shape: newest 10 electrical since 2020
python3 lookup.py --all "27927 E Main St"       # every permit (default is the 50 newest + a summary of all)
python3 lookup.py --schema                      # print tool definition

Hosted API + MCP (no install)

The same lookup is served read-only, no auth, from permits-api.secondlandings.ai (server.py, zero dependencies; see deploy/README.md):

Results are live; the server caches each query for 15 minutes and rate-limits per client (30/min) to protect the municipal portals. Known hosted-only gap: Tyler's hosted Civic Access (Redmond) returns 403 to datacenter IPs, so from the hosted endpoint a Redmond lookup carries the Assessor index plus a next_step with reason: source_blocked instead of live Redmond records; run lookup.py locally for those. Every other source answers from the droplet. Run it yourself with python3 server.py or docker compose up — server.json is the MCP Registry manifest.

Parcel-number searches query every supported MyBuildingPermit and live city portal because a bare parcel number does not identify its city jurisdiction.

Address searches are routed by geometry, not the mailing city: the address is geocoded with King County's four-county locator and the point is tested against the city-limits polygons. A "Kent, WA" address that sits in unincorporated King County is searched as county, not Kent; an address with no city in it is routed correctly instead of fanning out to every jurisdiction; and Pierce-side addresses of Milton/Pacific/Auburn get a pierce: parcel id. The mailing city is only used when geocoding fails (jurisdiction.basis says which).

What you get

{
  "action": "found",
  "permit_count": 2,
  "searched": ["Renton (EnerGov)"],
  "permits": [
    {
      "permit_number": "E26000458",
      "type": "Residential Electrical Permit",
      "status": "Issued",
      "description": "Electrical Work (Garage & Garage Exterior): ...",
      "address": "1817 Morris Ave S Renton WA 98055",
      "jurisdiction": "Renton",
      "applied_date": "2026-01-28",
      "issued_date": "2026-01-28",
      "finaled_date": null,
      "expires_date": "2027-07-27",
      "portal": "https://permitting.rentonwa.gov",
      "record_url": null,
      "is_open": true
    }
  ],
  "trust_level": "live",
  "fetched_at": "2026-10-08T19:02:11+00:00",
  "parcel_id": "king:7222000353",
  "cite_as": "King County Permit Status (github.com/chaoz23/king-county-permit-status), queried 2026-10-08 via Renton (EnerGov)"
}

Per permit: permit_number, type, status, is_open (heuristic, census-tested weekly; null when the source exposes no status) with is_open_basis (finaled_date = certain, status-vocabulary = regex over the vendor's status word, null = unknown), description, address, jurisdiction, applied_date, issued_date, finaled_date, expires_date, portal, record_url (the specific record's URL when the source exposes one).

Multi-jurisdiction coverage

Coverage scorecard

Auto-generated from routing_data.json (python3 scripts/gen_scorecard.py --write). One row per King County city.

Legend — ✅ live (status + history) · 🗂️ index (valuation-reported building history · the number after ✅/🗂️ in Building is the record count at the city's QC address (see qc_addresses.json) — how much is really behind the row from the King County Assessor's parcel index — no status, no sub-permits, dense since ~2023) · ➖ L&I electrical only (2020+) · ⚠️ gap (city self-runs electrical, not yet integrated)

Health = last weekly live probe of the city's source (scripts/source_health.py, 2026-10-12): ✅ answered with records · ⚪ answered, zero rows for a known-good query · ⛔ blocked (403) · ❌ down · ❔ unchecked · — no live source

Coverage: 20/39 live · 19/39 indexed (issued history via the Assessor; status needs the city portal). Plus King County (unincorporated) for county-level permits (septic, critical areas, grading).

⚠️ Electrical gaps: Des Moines, Milton, Tukwila. These cities self-run their electrical program (so L&I is skipped) and are not on MyBuildingPermit, leaving their electrical permits in no feed we search. MBP cities that self-run electrical (Burien, Federal Way, Kirkland, Mercer Island, Sammamish) are not gaps — verified 2026-07-15 that MBP carries their electrical history. Closing the remaining gaps is tracked in the coverage epic.

ℹ️ Split-county cities: Milton (mostly Pierce), Pacific and Auburn straddle the King/Pierce line. Each city issues its own permits for the whole city, so a live row applies to both sides; but the 🗂️ Assessor index is King County's, so for an indexed split city (Milton) only King-side parcels have index rows — Pierce-side addresses get the portal pointer only. Pierce County's portal is not searched. Parcel ids are county-namespaced (king:… / pierce:…) for this reason.

All 39 incorporated King County cities are recognized. Cities outside the searchable sources are flagged with their municipal portal URL rather than being treated as unincorporated King County.

For comma-separated addresses, the locality component takes precedence over city names that also appear in streets (for example, Kent Kangley Rd, Covington). If a Renton address cannot be resolved to a parcel for its live EnerGov search, the result retains Renton's portal as an actionable fallback. Seattle address and exact permit-number searches query all four official SDCI Open Data datasets; parcel-only Seattle lookup is not yet supported. Kent's official permit-status page currently requires users to sign in to the city portal, so Kent results include that page as a manual fallback.

Exit codes

For agents

tool.json at the repo root contains the full tool definition in Anthropic/OpenAI tool-call format. An agent can load it directly or fetch the live version:

python3 lookup.py --schema

{
  "name": "king_county_permit_status",
  "description": "Look up building permit history and status for any King County, WA property...",
  "input_schema": {
    "type": "object",
    "properties": {
      "query": {
        "type": "string",
        "description": "Street address, 10-digit parcel number, or permit number..."
      }
    },
    "required": ["query"]
  },
  "output_schema": { ... },
  "invocation": {
    "command": "python3 lookup.py --pipe \"{query}\"",
    "exit_codes": {
      "0": "action=found — permits[] is populated",
      "1": "action=none or refine — no permits or connection issue",
      "2": "action=reject — bad input"
    }
  }
}

Pipeline pattern:

# Get all permits at an address, extract open ones
python3 lookup.py --pipe "1817 Morris Ave S, Renton WA" \
  | python3 -c "
import sys, json
d = json.load(sys.stdin)
open_statuses = {'Issued', 'In Review', 'On Hold', 'Pending'}
open_permits = [p for p in d.get('permits', []) if p['status'] in open_statuses]
print(json.dumps(open_permits, indent=2))
"

Related tools in this series:

• king-county-address-to-parcel-number — resolve an address to its parcel number
• wa-contractor-license — verify WA contractor license status and violations
• king-county-property-tax-appeal — build a filing-ready tax appeal packet

Requirements

• Python 3.10+ (stdlib only, no dependencies)
• Network access to the municipal and county hosts in the source table above (MyBuildingPermit, Tyler/Accela/SmartGov/eTRAKiT/LAMA portals, Seattle and Bellevue open data, gismaps.kingcounty.gov, blue.kingcounty.com, secure.lni.wa.gov)

Development

Run the network-free regression suite with:

python3 -m unittest discover -s tests -v

Contractor search

python3 lookup.py --contractor "Brambila"        # what a contractor has pulled
python3 lookup.py --license BRAMBSL123AA         # same, by L&I license number

Searches MyBuildingPermit's People index across all of its jurisdictions (Auburn, Bellevue, Bothell, Burien, Edmonds, Federal Way, Issaquah, Kenmore, King County, Kirkland, Mercer Island, Mill Creek, Newcastle, Sammamish, Snoqualmie), concurrently, splitting busy contractors by applied-date window; same schema and summary. coverage_note says which cities are not searched by contractor (Seattle, Renton, Redmond, Shoreline, SeaTac, Woodinville, Normandy Park, Carnation — their portals' contractor searches aren't implemented). Pair with wa-contractor-license for the license/bond/insurance check. Also on the hosted API: ?contractor= / ?license=, and the MCP tool's contractor / license arguments.

Quality checks

Four layers, each answering a different question:

License

MIT — see LICENSE. Permit data comes from the public municipal and county sources named above; cite results with the cite_as field.