13F hedge-fund holdings with AI summary

Query any filer's 13F by CIK: latest filing date, total portfolio value, holding count, top positions, plus an AI summary of what changed. $0.10/call via x402.

$0.10 USDC / call free trial: 2/day per IP contabo

Endpoint

GET https://contabo-vps.taild7e69a.ts.net/13fintel/api/13f

Data source: SEC EDGAR 13F filings + LLM summarization

Parameters

Param	Type	Description
`cik`	query param	10-digit CIK, e.g. 0001067983 (Berkshire Hathaway)

Example request

curl "https://contabo-vps.taild7e69a.ts.net/13fintel/api/13f?cik=0001067983"

Example response

{
  "filer": "BERKSHIRE HATHAWAY INC",
  "latest": {"filingDate": "2026-08-14", "holdingCount": 89},
  "topHoldings": [{"issuer": "AMERICAN EXPRESS CO", "valueUsd": 50419898471000}],
  "aiSummary": "..."
}

How payment works (x402)

Call the endpoint without any payment header → you get 402 Payment Required with the exact price, the USDC contract, the network (eip155:8453 = Base), and the pay-to address.
Pay 0.10 USDC on Base to the pay-to address — with any wallet, the Coinbase CDP x402 SDK, or any x402 client library.
Retry the same request with the X-PAYMENT header set to the base64-encoded signed payment payload → 200 with JSON.

# 1. Get the 402 payment requirements
curl -s "https://contabo-vps.taild7e69a.ts.net/13fintel/api/13f"

# 2. Pay 0.10 USDC on Base, then retry with the payment proof
curl "https://contabo-vps.taild7e69a.ts.net/13fintel/api/13f" \
  -H "X-PAYMENT: <base64-signed-payment-payload>"

Facilitators: Coinbase CDP and PayAI (no API key needed for either). Scheme: x402 v2 exact. Asset: USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base.

Free trial

Every IP gets 2/day free calls to this endpoint — no payment needed. Free calls run automatically when you call without an X-PAYMENT header. The X-Free-Remaining response header shows how many free calls you have left today. When the quota is exhausted, the request falls through to the normal 402 payment flow.

FAQ

Where do I find a CIK?
Search EDGAR company search; well-known filers' CIKs are public.

How current is the data?
13Fs are filed quarterly within 45 days of quarter-end.

Does it show position changes?
Yes — the AI summary highlights new, exited, and resized positions.

Do I need an API key?
No. This API uses x402: call the endpoint, receive a 402 Payment Required with the price, pay in USDC on Base, and retry with the X-PAYMENT header. No signup, no API key, no account.

Which facilitators are supported?
Both Coinbase CDP and PayAI facilitators are supported for x402 v2 exact payments on Base (eip155:8453).

What if my payment is too low?
The facilitator verifies the on-chain amount against the price. If underpaid, you get 402 again; pay the full amount and retry.

All 37 x402 API docs · Postman collection (download) · About this API