CFR Citers API: Which public companies cite a given CFR title and part in their SEC — Federal Register

Which public companies cite a given CFR title and part in their SEC filings — exact-phrase full-text join aggregated per registrant with filing counts, forms and dates. Screen exposure to specific provisions in one call.

$0.02 per call — pay with prepaid card credits (Authorization: Bearer ck_live_…, packs from $1) or with USDC over x402: call it, get 402 with the price, retry signed. Failed calls are never charged.

How do you call it?

GET /v1/impact/cfr — product id impact_cfr_citers. Over MCP, call answerpool_get with product_id=impact_cfr_citers.

curl "https://answerpool.io/v1/impact/cfr?cfr_title=17&cfr_part=240"

# with a prepaid credit key
curl -H "Authorization: Bearer ck_live_..." "https://answerpool.io/v1/impact/cfr?cfr_title=17&cfr_part=240"

Live call: https://answerpool.io/v1/impact/cfr?cfr_title=17&cfr_part=240 · JSON sample: /v1/samples/impact_cfr_citers

What does the answer look like?

A representative response, the same static sample served at /v1/samples/impact_cfr_citers.

companies

{
 "as_of": "2026-09-02T20:00:00Z",
 "query": "17 CFR 240",
 "total_filing_matches": 128,
 "count": 1,
 "companies": [
  {
   "cik": "0000320193",
   "company": "Apple Inc.",
   "filings": 2,
   "forms": [
    "10-K"
   ],
   "latest_filed": "2026-08-15",
   "matched": [
    "17 CFR 240"
   ]
  }
 ],
 "refresh_after": "2026-09-17T11:15:00.000Z"
}

How fresh is it, and where does the data come from?

The fastest source behind this answer can change every 15 minutes, so every response carries a refresh_after timestamp — right now it would be 2026-09-17T11:15:00.000Z. Schedule the next call on that value rather than on a guess.

• Federal Register (US federal public domain) — upstream: https://www.federalregister.gov/api/v1
• SEC EDGAR (US federal public domain) — upstream: https://efts.sec.gov

Method version 0.1.0 · serving cache 1 day · every response carries a result_id you can resolve at /v1/provenance.

When should you use it?

Your obligations map to known CFR parts and you want the citing issuers.

What you skip building

• EDGAR full-text syntax
• per-registrant aggregation

When should you not use it?

Broad topic screens — use the rule impact map or regulation search.

Where else can you find this?

• Catalog entry (JSON, free)
• OpenAPI schema — input and output types, prices, the 402 flow
• llms.txt — every product in one plain-text document