@pipeworx/fjc-judges

Biographies and appointment records of every US federal (Article III) judge since 1789 — Supreme Court justices, court of appeals and district court judges — from the Federal Judicial Center's Biographical Directory.

Part of Pipeworx — an MCP gateway connecting AI agents to 1864+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• fjc_judge_lookup(name) — one judge's full record: every appointment with court, title, appointing president and party, ABA rating, nomination / hearing / confirmation / commission dates, Senate vote, chief-judge and senior-status dates and how service ended; plus birth, death, education and career. Answers "who appointed Judge X", "when was X confirmed", "is X still serving".

• fjc_judges_by_court(court, status?) — judges of one court (e.g. "Ninth Circuit", "Southern District of New York", "Supreme Court"). status is active (default — active service only), serving (active or senior) or all.

• fjc_judges_by_president(president, court_type?) — every Article III appointment a president made, with totals by court level. Joseph R. Biden: 235 appointments of 230 distinct judges (one judge can be appointed twice, e.g. Ketanji Brown Jackson to the D.C. Circuit and then the Supreme Court).

• fjc_seat_succession(name | seat_id, court?) — the chain of holders of one judgeship in order, with the named predecessor and successor of the judge asked about ("who did Judge X replace"). Built from the directory's Seat ID, whose last two digits are the holder's sequence on that seat.

Every response carries source, licence and data_as_of (when the FJC last regenerated the directory).

Related MCP server: KnowJudges

Auth

Keyless.

Data sources

• Federal Judicial Center, Biographical Directory of Article III Federal Judges, 1789–present. Public domain (a work of the US federal government).

The FJC publishes the directory as a single export (~5 MB, ~4,000 judges, regenerated daily), not as a query API. The pack reads it per isolate and keeps the parsed rows for up to six hours, so the first call on a cold isolate takes about a second and the rest take milliseconds.

Things the next person would otherwise rediscover:

• One row per judge, with up to six appointments flattened into numbered columns (Court Name (1) … (6)). A judge elevated from district court to a circuit has two appointments; counts "by president" are appointments, and the response reports distinct judges alongside.

• Empty cells are frequently a single space, not empty — trim before testing.

• "Active" means no termination date and no senior-status date on that appointment. Senior judges still hear cases; use status: "serving" to include them.

• Presidents are written as the FJC writes them ("George H.W. Bush", "Joseph R. Biden"). A surname that matches two presidents returns ambiguous_president with both candidates rather than merging them.

• Magistrate, bankruptcy and state judges are not Article III judges and are not in this directory.

Quick Start

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

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

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/fjc-judges/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 1864+ 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/fjc_judge_lookup \
  -H 'Content-Type: application/json' \
  -d '{"name":"Ketanji Brown Jackson"}'

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

Run it from npm

@pipeworx/mcp-fjc-judges is a local stdio bridge to the Pipeworx gateway: your MCP client starts it with npx, and it forwards every call to the same https://gateway.pipeworx.io/fjc-judges/mcp endpoint shown above. It needs network access; there is no offline mode.

{
  "mcpServers": {
    "fjc-judges": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-fjc-judges"]
    }
  }
}

Without a key it calls anonymously, capped at 50 calls a day. A free account raises that to 200 a day: get a key at https://pipeworx.io/signup and add "env": { "PIPEWORX_API_KEY": "<your key>" } to the server entry. The key is sent as a Bearer token, the same way a hosted connection sends it, so calls are metered and billed exactly as they are there.

It lists only this pack's tools by default. Set PIPEWORX_META_TOOLS=1 to also list ask_pipeworx and the other gateway-wide tools.

Behind an HTTPS proxy: Node's built-in fetch does not read HTTPS_PROXY by default. Newer Node releases honour it when NODE_USE_ENV_PROXY=1 is set; check your Node version's documentation.

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 Fjc Judges data" })

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

More

• Docs and guides

• pipeworx.io

License

MIT