GroundSignal
Data access

Intelligence Desk & Commercial API

Use the published property-research feeds today. Programmatic access remains a separately described pre-sale until the API launches.
API in development · pre-sale open

Supported towns: Park Ridge, Wilmette, Winnetka, Glencoe, Kenilworth. Coverage follows these municipal footprints, not the whole county. Source dates and missing-record limits appear with the data.

Need to see the output first? Inspect a real appeal-list sample or a trade-list sample, including the CSV field dictionary.

Rates

Two ways in · billed monthly · cancel any time

01 · Web desk

Live now

Intelligence Desk

$100/ month

Six research feeds as sortable tables, plus the full appeal and trade lead CSVs for supported towns. Available in the app today without writing code.

  • Six feeds, sortable tableslive
  • Raw trade signals — ages, statuses, model scoreslive
  • Filter any feed, sort any columnlive
  • Feed exports and both full lead CSVslive
  • Refreshed with every data releaseauto

02 · REST API

Pre-sale

Commercial API

$200/ month$500/mo at launch for new subscribers

Pro research tools and Desk are available in the app today. JSON access to the records, entity graph and feeds is planned; the API has not launched.

  • $200/mo while continuously subscribedlock
  • Everything in Pro, todaylive
  • Intelligence Desk includedlive
  • API keys on launch daylaunch
  • Licensed for commercial useterms

Billed monthly through Stripe. Cancel any time; pre-sale charges are not refundable. See the refund policy and terms.

Try the research path in two minutes

  1. 1. Choose a town and a question

    Start with appeal prospecting or trade territory research. Open its public sample to see real rows, current counts and source dates.

  2. 2. Review the evidence

    Download the redacted sample and inspect the field dictionary. Assessment and permit gaps need further review; they do not establish an outcome or a homeowner’s intent.

  3. 3. Use the included tools

    An active Desk subscription opens the feed tables and full lead CSVs. Commercial API adds Pro’s parcel research tools now and programmatic access when it launches.

Preview the feed workspace

One list or ongoing research?

Desk includes the same full lead CSVs. Choose the access arrangement that fits your work. Coverage is Park Ridge, Wilmette, Winnetka, Glencoe, Kenilworth; these are municipal records, not a countywide list.

One-time list · $299 trade / $495 appeal

One product for the town selected at checkout. Download the full matching pool from your account while the purchase remains paid and the list is offered. Each download uses the current data release; it is not a frozen snapshot. No subscription is required.

Intelligence Desk · $100/month

Six live feed tables plus both full lead-list CSVs in supported towns. Downloads require active subscription access. Cancellation takes effect at the end of the paid period; a separately purchased one-time list keeps its own access.

Commercial API · $200/month pre-sale

Everything in Pro and Desk in the app today under a commercial-use license. The REST API is in development. Programmatic access begins at launch; pre-sale charges begin now.

Lead files carry a single-firm license, without resale or redistribution. Downloaded files remain subject to those license conditions, including removal requests. A license does not provide exclusive territory. See the list terms and monthly access details.

Upcoming connector

Explore the Muse use cases

See how questions about properties and local records could use source-linked evidence in Muse. The public demo uses real, redacted records. The connector is upcoming; this preview does not provide an installed integration, account authorization or new API access.

Open the Muse preview

Endpoint reference

This is the planned launch surface. The API opens at launch; the pre-sale locks your rate at $200/mo. The same data is browsable today — feed dashboards at /feeds, every record on the site itself. Request and response windows are illustrative; field shapes may change before launch.

  • JSON over HTTPS, key-based authentication
  • Source agency and as-of date on every record
  • Estimates and inferences labeled, never mixed with facts
  • Rate limits and bulk endpoints sized for commercial use

GET/v1/parcels/{pin}

Planned parcel record, source dates and links to available assessments, sales, permits and appeals.

Planned request — unavailable during pre-sale
GET /api/v1/parcels/{14-digit-pin}
Authorization: Bearer {your-api-key}
Proposed field outline — not a live response
{
  "pin": "parcel identifier",
  "address": "published property address",
  "assessed_total": "published assessed value",
  "owner": "entitled taxpayer association",
  "release": "source and release metadata"
}

GET/v1/feeds/appeal-leads

Planned JSON access to the appeal research pool. The current criteria and real sample rows are available on the appeal-firm product page.

Planned request — unavailable during pre-sale
GET /api/v1/feeds/appeal-leads?city={town}
Authorization: Bearer {your-api-key}
Proposed field outline — not a live response
{
  "feed": "appeal-leads",
  "release_id": "active release identifier",
  "criteria": "documented research screen",
  "rows": "matching parcel records",
  "next": "pagination cursor, if present"
}

GET/v1/sales?since=

Planned access to published sale records across supported towns, with entitled deed parties and source context.

Planned request — unavailable during pre-sale
GET /api/v1/sales?since={date}
Authorization: Bearer {your-api-key}
Proposed field outline — not a live response
{
  "since": "requested date",
  "rows": "published sales and permitted party fields",
  "next": "pagination cursor, if present",
  "release_id": "active release identifier"
}

GET/v1/owners/{id}/holdings

Planned administrative ownership links. Taxpayer associations are not verified title or proof of beneficial ownership.

Planned request — unavailable during pre-sale
GET /api/v1/owners/{entity-id}/holdings
Authorization: Bearer {your-api-key}
Proposed field outline — not a live response
{
  "owner_id": "record association identifier",
  "holdings": "parcels linked in the available records",
  "release": "source and release metadata"
}

POST/v1/webhooks

Planned release notifications for an authorized destination. No webhook registration or delivery is available during pre-sale.

Planned request — unavailable during pre-sale
POST /api/v1/webhooks
Authorization: Bearer {your-api-key}
Body: authorized URL and requested event types
Proposed field outline — not a live response
{
  "event": "release.published",
  "release_id": "published release identifier",
  "published_at": "publication timestamp",
  "cursor": "link to changes, if available"
}

Also planned for launch: /v1/search?q=, /v1/streets/{slug}, /v1/changes?since=, and per-parcel /sales, /permits and /appeals subresources.

Planned API workflows

1.Appeal-lead pull for a law firm

Planned API workflow: review a research pool before outreach.

  1. 1.1Pull the current list: GET /v1/feeds/appeal-leads. Each row is a matching residential property assessed more than 10% above its peer median, with no recorded appeal from 2024 onward. An assessment increase is a different signal.
  2. 1.2For each retained lead, fetch the dossier: GET /v1/parcels/{pin} — prior assessment, sale history and permit record in one call.
  3. 1.3Refresh after each data release and review the current filing history. A missing filing does not establish that the owner is unrepresented; published records may lag.

2.Trade-lead sync into a CRM

Planned API workflow: maintain a reviewed territory research list.

  1. 2.1Pull GET /v1/feeds/trade-leads — pre-1985 homes with no building matching permit in the available county feed. Coverage varies by town and date; verify municipal records and actual condition.
  2. 2.2Upsert into the CRM keyed on pin; map estimated_value and year_built to lead fields.
  3. 2.3On each release.published webhook, pull again and close leads that now show permit activity.

3.Portfolio monitoring by webhook

Planned API workflow: review changes in linked records.

  1. 3.1Register once: POST /v1/webhooks with "events": ["release.published"].
  2. 3.2On delivery, pull GET /v1/sales?since= the prior release date and match grantee against the entities you track.
  3. 3.3For each watched owner, GET /v1/owners/{id}/holdings and diff parcel_count against your stored copy.

API launch updates

Not ready to reserve?

Leave your email and what you'd build. We'll write once when the API opens.