finance.thirteen-f

Parsed institutional holdings from a 13F-HR filing. By investment-manager CIK (e.g. 1067983 = Berkshire Hathaway). Returns each holding's nameOfIssuer, cusip, market value (whole USD per the modern Form 13F convention), shares/principal amount + type, putCall flag for options, and voting authority (sole/shared/none). Sorted by value descending. Pass formType for amendments (13F-HR/A) or non-filings (13F-NT). Backed by SEC.gov; underlying 13F filings are public records.

Overview

The 13F API returns parsed institutional holdings from an SEC Form 13F-HR filing, by investment-manager CIK — the quarterly portfolio disclosures of large institutional managers, structured for analysis.

Pass a manager CIK (e.g. 1067983 for Berkshire Hathaway) and get each holding's issuer name, CUSIP, market value (whole USD per the modern Form 13F convention), shares or principal amount and type, put/call flag for options, and voting authority — sorted by value descending. Pass formType for amendments (13F-HR/A) or notices. Underlying 13F filings are public records from SEC.gov. No API key — pay per call with x402.

Use cases

• Let an investing agent pull a fund's latest reported holdings and rank positions by market value.
• Track changes in an institution's portfolio quarter over quarter by diffing filings.
• Enrich an equities model with institutional ownership keyed by CUSIP.
• Ground a markets assistant in real 13F disclosures instead of summarized holdings.

Parameters

Code samples

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/finance/thirteen-f?managerCik=12345&formType=13F-HR&limit=25'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/finance/thirteen-f?managerCik=12345&formType=13F-HR&limit=25' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/finance/thirteen-f?managerCik=12345&formType=13F-HR&limit=25'

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.finance.thirteenF({
  "managerCik": "12345",
  "formType": "13F-HR",
  "limit": 25
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.finance.thirteen_f(managerCik="12345", formType="13F-HR", limit=25)

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "finance.thirteen-f",
    "arguments": {
      "managerCik": "12345",
      "formType": "13F-HR",
      "limit": 25
    }
  }
}

Response

{
  "ok": true,
  "items": [
    {
      "nameOfIssuer": "example",
      "titleOfClass": "example",
      "cusip": "example",
      "valueUsd": 1,
      "sharesOrPrinAmt": 1,
      "sharesOrPrinAmtType": "SH",
      "investmentDiscretion": "example",
      "putCall": "PUT",
      "votingAuthority": {
        "sole": 1,
        "shared": 1,
        "none": 1
      }
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  },
  "meta": {
    "query": {
      "managerCik": "example",
      "formType": "example",
      "limit": 1
    },
    "cik": "example",
    "managerName": "example",
    "filing": {
      "accessionNumber": "example",
      "form": "example",
      "filingDate": "example",
      "periodOfReport": "example",
      "infoTableUrl": "https://example.com",
      "documentUrl": "https://example.com"
    },
    "totalValueUsd": 1
  }
}

FAQ

What identifier do I pass for a 13F lookup?

The investment manager's SEC CIK (e.g. 1067983 = Berkshire Hathaway). Results are that manager's reported holdings from their 13F-HR filing.

Are option positions and voting authority included?

Yes — each holding includes a put/call flag for options and the voting authority (sole/shared/none), alongside issuer, CUSIP, value, and shares.

Do I need an API key to use the thirteen f API?

No. finance.thirteen-f is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.

How much does the thirteen f API cost?

$0.0072 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.

Can I try the thirteen f API for free first?

Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.

Which networks and tokens are supported?

USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.

How do I call finance.thirteen-f from an AI agent or MCP host?

Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

• /api/directory — full catalog of every endpoint
• /openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
• /.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
• /.well-known/mcp/server-card.json — MCP SEP-1649 server card
• /llms.txt — plain-text manifest for LLM ingestion