# Isopleth

> One API for public geospatial facts about any US location: send a coordinate or address, get 351 typed fields
> (flood zone, terrain, soils, power grid, hazards, climate, sun and wind, demographics) from 95 public sources,
> each with its source, license and attribution. Parcel records (owner, acreage, values, last sale, boundary) in
> 32 states plus DC. REST + JSON and a hosted MCP server.

## Connect
- REST base URL: https://api.isopleth.dev . Auth header: `Authorization: Bearer $ISOPLETH_KEY`. Never put the key in a URL.
- MCP server (Streamable HTTP): https://api.isopleth.dev/mcp . OAuth sign-in (Claude, ChatGPT, Cursor, VS Code, Codex) or the same Bearer header.
- Claude Code: `claude mcp add --transport http isopleth https://api.isopleth.dev/mcp`
- Codex: `codex mcp add isopleth --url https://api.isopleth.dev/mcp`
- OpenAPI: https://isopleth.dev/openapi.json
- Keys: https://isopleth.dev/signup/ (1,000 free lookups a month, no card)

## Main endpoints
- POST /v1/fetch: {"lat","lng"} or {"address"}, plus "fields": [...] or "preset". 1 lookup per location per 50 fields.
- POST /v1/fetch/batch: {"locations": [...]}, same options. Results index-aligned.
- POST /v1/geocode: {"address"} -> lat, lng, normalized_address, accuracy.
- POST /v1/enrich: parcel record by address, lat/lng or apn+state. 5 lookups per matched parcel.
- POST /v1/search: parcels by state, county, acreage, owner, land use, value. 25 lookups per page of up to 100.
- POST /v1/proximity: {"lat","lng"} or {"address"}, "features" or "categories" -> nearest feature of each type with distance. 1 lookup per 50 underlying fields (usually 1).
- POST /v1/ask: {"question"} -> deterministic plan, answer and result, metered like the planned call. POST /v1/ask/plan: the plan only, free.
- POST /v1/runs: async batch, enrich or search job; GET /v1/runs/{id} and /v1/runs/{id}/results to poll. Metered like the underlying calls.
- GET /v1/parcels/coverage, GET /v1/meta/fields, GET /v1/usage: free.
- Presets: boundaries, building_lookup, data_center_siting, flood_risk, grid_interconnect, land_cover, natural_hazard, points_of_interest, site_selection, solar_siting, storage_siting, terrain, utilities, wildfire_underwrite, wind_siting

## MCP tools
- fetch_location: Get public-data facts for one US location, given lat+lng or a street address, and a preset and/or a list of field names.
- fetch_batch: Get the same preset and/or fields for several US locations in one call (up to your plan's batch size: 10 on Free, 100 on paid plans).
- geocode_address: Turn a US street address into lat/lng plus the normalized address, using the US Census geocoder (placed along the street from the house-number range, not a rooftop).
- list_presets: List the named field bundles (presets) such as terrain, flood_risk, natural_hazard, utilities, solar_siting and data_center_siting, with their field names.
- search_fields: Search the field catalog by words in the field name or description (e.g.
- describe_fields: Full catalog entries for named fields: description, type, unit, source, source URL, license, attribution, refresh interval and presets.
- parcel_enrich: Get the public parcel record for one US parcel, located by lat+lng, street address, parcel_id (from an earlier result) or apn+state: owner, situs and mailing address, land use, zoning, assessed/land/improvement value, last sale, year built, legal description, plus boundary calcs (acres, square feet, perimeter, centroid, bounding box, compactness, minimum rectangle) and the GeoJSON boundary.
- parcel_search: Find parcels in one or more states by county, acreage, owner name, land-use code or words, total/land value, sale price or date, year built, ZIP, city, a bbox or a GeoJSON polygon, or generic column filters ({field, op, value} with op eq, ne, lt, lte, gt, gte, in, between, contains, starts_with, exists, missing).
- parcel_coverage: States with parcel data: parcel counts, counties, publisher, licence, data vintage, refresh cadence and the share of parcels with each column filled (owner, values, sale, zoning...).
- proximity: For one point or address, the nearest mapped feature of each requested type (substation, transmission_line, power_plant, gas_pipeline, highway, railroad, airport, hospital, school, fire_station, river, wetland, superfund_site, cell_tower and more; or whole categories: power, pipelines, water, transportation, places, environment, telecom), sorted nearest first, with distance in m/km/mi, the feature's name and attributes where published.
- plan_question: Map a plain-English question about a US place or area to the right tool, its exact arguments (fields, preset, filters, feature types) and the estimated lookup cost, without running it.
- ask: Plan a plain-English question deterministically (as plan_question) and run the plan: point facts, nearest features, a parcel lookup, a parcel search or a geocode.
- start_run: Submit work too large for one call and poll it with get_run.
- get_run: Status, progress and lookups charged for a run from start_run, plus a page of its results (available while it runs).
- get_usage: Your plan, its limits (batch size, requests per minute, daily cap), lookups remaining this period and recent daily usage.

## Docs
- [Quickstart](https://isopleth.dev/docs/)
- [API reference](https://isopleth.dev/docs/reference)
- [Field catalog](https://isopleth.dev/docs/fields)
- [MCP server](https://isopleth.dev/docs/mcp)
- [Code and agent SDKs](https://isopleth.dev/docs/agents)
- [Parcels and coverage](https://isopleth.dev/docs/parcels)
- [Proximity, Ask and Runs](https://isopleth.dev/docs/tools)
- [Lookups and billing](https://isopleth.dev/docs/billing)
- [Use cases](https://isopleth.dev/use-cases/)

## Agent skills (SKILL.md)
- [Land Read](https://isopleth.dev/templates/land-read/SKILL.md): Terrain, soil and land-cover facts for one site, every value tied to its public source.
- [Power Read](https://isopleth.dev/templates/power-read/SKILL.md): Grid and utility context for one site: nearest transmission line and voltage, substation, power plant, gas pipeline, utility territory and water and sewer service.
- [Hazards Read](https://isopleth.dev/templates/hazards-read/SKILL.md): Flood, wetland, wildfire and severe-weather exposure for one site, cited to FEMA, USFWS, USGS, NOAA and state fire-agency sources.
- [Insurance Book Monitoring](https://isopleth.dev/templates/insurance-book-monitoring/SKILL.md): Re-screen a list of insured properties for flood, wildfire and severe-weather exposure in batches, and route anything that crosses a threshold to manual review.
- [CRM Address Cleanup](https://isopleth.dev/templates/crm-address-cleanup/SKILL.md): Turn a messy list of CRM or lead addresses into normalized records with coordinates, and an explicit review queue for anything that did not match.
- [Parcel Discovery](https://isopleth.dev/templates/parcel-discovery/SKILL.md): Find parcels that match a brief (state and county, acreage, land use, value, last sale) and return a clean shortlist with owner, acreage, value and location.
- [Parcel Enrich](https://isopleth.dev/templates/parcel-enrich/SKILL.md): The full public record for one parcel (owner, mailing address, land use, zoning, values, last sale, legal description, acreage) plus flood, terrain, wetland, utility and road facts at it.
- [Land Deal Screener](https://isopleth.dev/templates/land-deal-screener/SKILL.md): Screen a land deal in one call: the parcel record and price history against flood, wetland, protected-area, habitat, slope, soil, access and utility red flags.
- [Solar/Wind Site Prospecting](https://isopleth.dev/templates/solar-wind-site-prospecting/SKILL.md): Find large rural parcels and rank them for utility-scale solar or wind: resource, distance and voltage to the grid, slope, flood, wetlands and protected land.
- [Absentee Owner Finder](https://isopleth.dev/templates/absentee-owner-finder/SKILL.md): List parcels whose owners' mailing address is in another state (or another city), with the owner and mailing address, for outreach and acquisition lists.