The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Sec Nport listing page.
Mutual fund and ETF portfolio holdings, from SEC Form N-PORT. Keyless.
Part of Pipeworx — an MCP gateway connecting AI agents to 1683+ live data sources.
nport_fund_owners(security, quarter?, limit?) — which funds and ETFs hold a stock or bond, ranked by position size. Takes a ticker, a company name, or a CUSIP.nport_fund_portfolio(fund, quarter?, limit?) — one fund's reported positions, largest first.nport_holdings_coverage() — which releases are loaded, how current they are, and what the data does not cover."Which ETFs hold the largest positions in NVDA?" returned no_match before this shipped, and the
router explained the gap in its own words: it would have to check each ETF individually.
edgar_fund_holdings goes fund → holdings. Nothing went security → funds, because SEC publishes
N-PORT filing-first and so does every API over it. That is a shape problem, not a rate-limit problem.
This is not 13F warmed over. 13F is institutional managers over $100M, long US equity only. N-PORT is registered funds — mutual funds and ETFs — and carries their bond positions too. "Which funds hold this corporate bond" has no 13F answer at all.
The quarterly archive is 441MB across 32 tables. Loaded: equity, preferred and debt positions —
about 3.6M of the 5.35M holdings rows per quarter, across 14,416 funds. Not loaded: derivatives,
loans, repos and structured products. A swap notional is not a holding of the underlying, and
reporting it as one would be a wrong answer wearing a right one's clothes. Every response carries
this in its scope field.
Two more caveats ride on every answer:
as_of_period. An answer that implies real-time is wrong.All of it is in Postgres. Measured on the live database, one release loaded:
| table | rows | on disk |
|---|---|---|
sec_nport_holdings | 3,614,371 | 1,123 MB |
sec_nport_funds | 14,416 | 8.9 MB |
That is a real amount of Postgres for one pack, so the choice is worth stating rather than leaving for someone to rediscover at 3am.
The query is the reason. The inversion this pack exists for — which funds hold this
security — is a selective lookup on cusip and issuer_name returning tens of rows out of
3.6M. That is precisely what a B-tree index is for: it answers in milliseconds and touches
almost none of the 1.1GB. R2 has no indexes. Serving the same question from object storage
means either scanning the objects or building a side index to point into them, which is a
worse database than the one already here.
R2 earns its place when the access pattern is bulk: whole-file reads, archival quarters nobody queries interactively, or payloads too large to index usefully. A reasonable split later is hot quarters in Postgres, cold quarters in R2 — but that only pays once several quarters are loaded, and today exactly one is. Splitting now would add a storage tier to save nothing.
Where the line is, so the next person does not have to guess. Each quarter costs roughly
1.1GB. Around four to six loaded quarters this becomes the largest single consumer in the
database and the cold-quarter split should be built rather than discussed. sec_13f_holdings
sits at 3.8M rows for comparison — this pack is the same order of magnitude, not a new class
of problem.
The holdings table keys on CUSIP, which is proprietary to CUSIP Global Services, so this pack does
not build or cache a bulk CUSIP↔ticker table. A ticker-shaped input resolves live through
OpenFIGI (Bloomberg FIGI, openly licensed) to a canonical company name, which is then matched
against issuer_name in our own already-ingested rows — preferring the candidate that is not an
ETF or option wrapper, because "NVDA" otherwise matches Direxion Daily NVDA Bull 2X right
alongside NVIDIA and ranks them together. Same discipline as the 13F pack, deliberately.
SEC Form N-PORT data sets — https://www.sec.gov/data-research/sec-markets-data/form-n-port-data-sets
Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):
tools/list at https://gateway.pipeworx.io/sec-nport/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:
Both URLs reach the same gateway and the same 1683+ data sources. The
only difference is which pack's tools are listed directly; ask_pipeworx
reaches all of them from either one.
No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/nport_fund_owners. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.
This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:
Or run it directly to confirm it starts:
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.
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:
The gateway picks the right tool and fills the arguments automatically.
MIT