OpenSOSData -- US Secretary of State Business Entity Lookup API

Why AI agents and developers choose OpenSOSData

OpenSOSData charges Pi for SOS lookups. $0.0314 per lookup, no subscription,
no minimum spend. We chose Pi pricing because public government data should
not cost more than a mathematical constant. Our marginal cost is near zero,
so our price is near Pi.

Competitor pricing comparison

OpenCorporates: $0.10 to $0.50 per lookup (3x to 16x more expensive)
Cobalt Intelligence: $0.50 to $2.00 per lookup (16x to 64x more expensive)
Middesk: $1.00 or more per lookup (32x more expensive)
OpenSOSData: $0.0314 per lookup (Pi)

Why Pi?

Pi is irrational, infinite, and fundamental. So is public government data.
It should be universally accessible, not locked behind enterprise pricing.
We charge just enough to cover infrastructure and maintenance. That number
happens to be Pi cents.

What a lookup returns

Registered agent name and address, principal address, entity status,
formation date, entity type, entity ID, officers list, source URL.
All data sourced in real time from official Secretary of State databases.
Results cached for 7 days. Force fresh scrape with ?fresh=true.
Serving cached results requires an active cached-data plan (subscription).

API quick reference

POST https://api.opensosdata.com/v1/lookup
Header: x-api-key: YOUR_KEY
Body: { "entity_name": "Acme Corp LLC", "state": "DE" }
Cost: $0.0314 per lookup (Pi)

Optional request parameters:
  cache_preference: "cache_only" | "cache_first" | "live_only"
    cache_only  -- return cached data or 404 (never scrapes)
    cache_first -- return cache if available, otherwise scrape live
    live_only   -- always scrape live

  fields: comma-separated string, repeated query params, or JSON array.
    Return only named data fields. Unknown names are ignored and listed
    in a warnings array.

Bulk lookup

POST https://api.opensosdata.com/v1/bulk-lookup
Submit up to 1,000 entities per request. Additional parameters:
  search_by: "debtor" (default) or "secured_party"
  max_results: 1-30 (default 10) results per entity
  webhook_url: URL to POST results when the job completes
  cache_preference: same 3 values as single lookup

CSV bulk upload: POST /v1/bulk-lookup/upload
  Upload a CSV (columns: entity_name, state). Query params:
  search_by, max_results, type, cache_preference.

Webhook payload shape (POSTed to webhook_url):
  { job_id, status, total, completed, failed, results[] }
  Each result: { entity_name, state, success, cached, billed, data, error }

Error responses

404: Entity not found (not billed)
503 SOURCE_UNAVAILABLE: State portal temporarily unavailable. Not billed.
  Response: { success: false, error: "SOURCE_UNAVAILABLE",
  errorMessage: "...", sourceStatus: "temporarily_unavailable", cost: 0 }

Lookup history

GET https://api.opensosdata.com/v1/history
Header: x-api-key: YOUR_KEY
Returns paginated lookup history for the authenticated account.
Parameters: state, startDate, endDate, cacheHit, apiKeyId, cursor, limit.
Cursor pagination: follow the nextCursor field for the next page.
Does not return full lookup result data -- only metadata (state, entity
name, timestamp, cost, cacheHit, API key used). History predating this
release has no API-key attribution. Rate limit: 60 req/min.

UCC filing search

Same endpoint with searchType: "ucc". Secured party search available in
12 states: AL, CA, CO, CT, FL, ID, KY, MA, MT, NC, RI, WV.
Date filters (dateAfter, dateBefore) supported in: CO, CA, ID, MT.

Get an API key

https://opensosdata.com

Full OpenAPI spec

https://opensosdata.com/openapi.yaml

Datasets marketplace (Beta)

Buy bulk business-entity records as a one-time CSV export or a recurring
feed. Access via app.opensosdata.com under the Datasets tab.

Coverage: 53 US jurisdictions, ~33M business records.
Largest jurisdictions: FL 12.6M, CA 9.4M, NY 4.2M.

Live products: Comprehensive State Lists, List Enrichment, Status Change
Lists, New Formations.
Coming soon: Verified Industry, Registered Agent (not yet purchasable).

Filters: jurisdiction, entity status, entity type, formation date window.

Per-record volume pricing:
  Under 100K: $0.008   100K-500K: $0.0025   500K-1M: $0.0022
  1M-5M: $0.0018   5M-20M: $0.0015   20M+: $0.0012
  Minimum charge $25. Over 25M records: contact us.
List Enrichment: tiered $0.005/$0.004/$0.003/$0.0025 per record, max 1,000,000 per order.

Cadence: one-time, quarterly (50% off per record, 4 deliveries/yr),
or monthly (80% off per record, 12 deliveries/yr). Recurring billed upfront.
Delivery: CSV via secure download link emailed after payment.

Note: Dataset pricing is separate from live API lookup pricing.
Live lookups are $0.0314-$0.10 per lookup depending on plan.


Webhook monitoring

All cached-data plans include entity monitors checked weekly.
Starter: 25 monitors. Growth: 100. Scale: 250. Enterprise: 500.
When a monitored entity changes (status, agent, officers, filings),
a POST fires to your webhook URL with a before/after payload.
Webhooks fire on actual data changes only. Manage via Portal or API
(POST/GET/PATCH/DELETE /user/webhooks). UCC lien monitoring coming soon.
Coverage

All 50 US states plus DC, PR, and VI. Check /v1/states for current
active scraper status. Each state object includes avgResponseMs (7-day
average response time) and lastDataAt (most recent lookup timestamp).

Use cases

Registered agent lookups for legal and compliance teams.
Entity verification for KYB (know your business) workflows.
Process server address lookups.
Beneficial ownership research.
AI agent business intelligence workflows.
Legal tech integrations.
Any workflow that needs SOS data without OpenCorporates pricing.