Sec Beneficial Ownership

@pipeworx/sec-beneficial-ownership

SEC Schedule 13D / 13G beneficial-ownership filings — who holds 5%+ of a public company's stock, how (sole vs. shared voting/dispositive power), and — for 13D — why (Item 4 "Purpose of Transaction", the activist-investor signal). Parses the structured XML SEC has required since its 2024 rule, and falls back honestly (structured: false) on older plain-text filings instead of returning nothing.

Part of Pipeworx — an MCP gateway connecting AI agents to 1721+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• sec_13d_filings(ticker_or_cik, form_type?, limit?) — list an issuer's Schedule 13D/13G filings (and amendments), newest first. Each row flags whether it is structured XML or pre-2024 plain text.
• sec_13d_filing(ticker_or_cik, accession_number) — parse one filing: every reporting owner with percent of class, sole/shared voting power, sole/shared dispositive power, aggregate shares owned; for 13D, also Item 4's purpose text. Falls back to bounded plain text for pre-rule filings.
• sec_13d_amendment_diff(ticker_or_cik, accession_number) — given one 13D/A or 13G/A, find the same reporting group's prior filing in the chain and diff ownership %, voting/dispositive power (per owner), and (13D) whether the Item 4 purpose text changed.

Auth

Keyless. SEC EDGAR is free, public, and requires no API key — only a descriptive User-Agent, which this pack sends on every request per SEC's developer guidelines.

Data sources

• https://data.sec.gov/submissions/CIK##########.json — per-issuer filing index (form type, accession number, filing date, primary document name). Shared pattern with mcps/edgar.
• https://www.sec.gov/Archives/edgar/data/{cik}/{accession}/primary_doc.xml — the filing's structured XML, for filings on or after SEC's 2024 structured-data rule (SCHEDULE 13D / SCHEDULE 13G form types).
• https://www.sec.gov/Archives/edgar/data/{cik}/{accession}/{primary_document} — the filing's plain HTML/text document, for pre-rule filings (SC 13D / SC 13G form types).
• https://www.sec.gov/files/company_tickers.json — ticker/company-name to CIK resolution, via the shared resolveSecEntity helper (also used by mcps/edgar) — one resolver for every SEC-keyed pack rather than a second implementation here.

Traps worth knowing

• The submissions index's primaryDocument field for a structured filing is a VIEWER path, not the raw document. It reads like xslSCHEDULE_13D_X01/primary_doc.xml — fetching that exact URL returns rendered HTML (an XSLT transform applied server-side for browsers), not machine-readable XML, even though the filename ends in .xml. The actual structured XML always sits at primary_doc.xml directly in the accession's archive root, one directory up, regardless of which XSLT stylesheet variant (X01, X02, …) the viewer path names. This pack always fetches the root path for structured filings; mcps/sec-form-d relies on the same convention for Form D.
• SC 13D/SC 13G (pre-rule, plain text) vs. SCHEDULE 13D/SCHEDULE 13G (post-rule, structured XML) are the SAME form, different eras. SEC's 2024 structured-data rule changed the submission type string, not just the document format. Filter logic in this pack normalizes both to one family (13D / 13G) so a caller filtering by form type gets every era.
• previousAccessionNumber (when present) points to the ORIGINAL filing in the amendment chain, not the immediately preceding amendment. Confirmed live: three successive amendments by the same reporting group all carried the identical previousAccessionNumber (the 2024 original). It also is not universal — a later XSD revision (X0202, seen from at least one large institutional filer) omits it entirely. sec_13d_amendment_diff treats it as one signal of chain membership alongside reporting-owner-identity overlap, not as a direct pointer to "the prior filing."
• A 13D/A or 13G/A only restates the Items that changed. An amendment's items1To7 (13D) or items (13G) block may simply omit item2, item4, etc. if that item's content is unchanged from the prior filing — this is not a parsing failure, it is how SEC's schema allows amendments to be filed. sec_13d_filing and sec_13d_amendment_diff return null for an absent item rather than inventing content.
• Schedule 13G has no "purpose" field. 13D's Item 4 is "Purpose of Transaction" (free text); 13G's Item 4 is "Ownership" (amount/percent/voting power, already covered by reporting_owners). item4_purpose is only ever populated for 13D; for 13G it is null with a note explaining why.
• SEC egress is shared fleet-wide across every SEC/EDGAR pack (one outbound IP). Every tool here reads a bounded, specific set of filings — never a bulk crawl of an issuer's history. sec_13d_amendment_diff's backward scan for the prior filing is capped (MAX_CHAIN_SCAN = 6 filing fetches).

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{  "mcpServers": {    "sec-beneficial-ownership": {      "url": "https://gateway.pipeworx.io/sec-beneficial-ownership/mcp"    }  }}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/sec-beneficial-ownership/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{  "mcpServers": {    "pipeworx": {      "url": "https://gateway.pipeworx.io/mcp"    }  }}

Both URLs reach the same gateway and the same 1721+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/sec_13d_filings \  -H 'Content-Type: application/json' \  -d '{"ticker_or_cik":"IMXI","form_type":"all","limit":10}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/sec_13d_filings. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{  "mcpServers": {    "sec-beneficial-ownership": {      "command": "npx",      "args": ["-y", "@pipeworx/mcp-sec-beneficial-ownership"]    }  }}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-sec-beneficial-ownership

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Sec Beneficial Ownership data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT