US Codex MCP

An MCP server that enables AI agents to search, read, cite, and compare federal law including the US Code, CFR, public laws, bills, and executive orders. It supports tools for searching full text, fetching documents as markdown, viewing citations, legislative history, and comparing versions between releases.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

Vendor evidenceLegacy SSENo sign-inEndpoint checked 2026-11-01Operated by US Codex

MCP endpoint (Legacy SSE)

https://uscodex.org/mcp/sse

Vendor documentation

What its tools do

5 tools, grouped by the hints the server advertises. Hints are self-declared, not verified behavior.

Not annotated (5)

search
fetch
citations
history
compare

5 of 5 have a description · 0 of 5 declare behavior hints · 5 of 5 with parameters document them all

Checks and signals

Each line is separate evidence, not a trust score.

Passed Endpoint answered the live check · Nov 1, 2026, 12:46 PM UTC
Passed Official MCP Registry namespace is tied to uscodex.org · Nov 1, 2026, 12:32 PM UTC
Passed Endpoint is on the registry namespace domain · Nov 1, 2026, 12:32 PM UTC
Availability 1 of 1 checks passed in 30 days

What you can do with it

Search the full text of federal law by query or citation
Read specific legal documents or sections as markdown
View citations and legislative history for statutes
Compare text changes between different legal releases

Source and maintenance

Vendor evidenceRegistry 1.0.0

mcp-registry: org.uscodex/uscodex@1.0.0 Project website

Protocol and capabilities

Server: uscodex 0.1.0
MCP protocol negotiated in check: 2025-06-18
Tools: 5 advertised
Resources: Not advertised
Resource templates: Not advertised
Prompts: Not advertised

Server-advertised capabilities

{
  "tools": {
    "listChanged": false
  }
}

Server-provided instructions

Untrusted server output shown for inspection. It is not Koskamo guidance and is excluded from knowledge search.

Federal law as published by its official sources — United States Code, Code of Federal Regulations, Public Laws, Congressional Bills, Executive Orders — cross-linked, with every release of each code. Every tool answers with the site's markdown for a page: its frontmatter names the citation, release and canonical URL, and its links are paths `fetch` accepts. Start with `search` for words, or `fetch` for a citation.

Tools

5 advertised

search

Advertised by the server during the last successful anonymous check.

Search the full text of federal law: United States Code, Code of Federal Regulations, Public Laws, Congressional Bills, Executive Orders. Results are ranked across every corpus unless `corpus` narrows them, each with its citation, a link and the matching words. A query that is only a citation returns that document instead.

search input schema

{
  "type": "object",
  "required": [
    "query"
  ],
  "properties": {
    "date": {
      "type": "string",
      "description": "For a code, search it as it stood on this date (YYYY-MM-DD)."
    },
    "page": {
      "type": "integer",
      "default": 1,
      "description": "Page of results, 20 to a page."
    },
    "query": {
      "type": "string",
      "description": "Words, a \"quoted phrase\", NOT before a word to exclude it, or a citation."
    },
    "title": {
      "type": "string",
      "description": "For a code, search one title (\"11\", \"40\")."
    },
    "corpus": {
      "enum": [
        "usc",
        "cfr",
        "pl",
        "bills",
        "eo"
      ],
      "type": "string",
      "description": "Search one corpus only."
    }
  }
}

fetch

Advertised by the server during the last successful anonymous check.

Read a document or page of the site as markdown: a code section with its notes, a title's or unit's contents, a public law, a bill (at any version), an executive order. Paths also reach the corpus indexes ("/usc", "/pl?congress=118", "/bills?congress=119", "/eo") and each code's releases ("/usc/releases"). Links in the markdown are paths this tool accepts.

fetch input schema

{
  "type": "object",
  "properties": {
    "path": {
      "type": "string",
      "description": "A page of the site, as its path or full URL (\"/usc/26/61\", \"/pl/119/21\"). Give this or `citation`."
    },
    "notes": {
      "type": "boolean",
      "default": true,
      "description": "Include a section's source credit, notes and footnotes."
    },
    "release": {
      "type": "string",
      "description": "For a code, the release to read it at: a release point (\"119-21\") or a date (YYYY-MM-DD) for the release in force then. Defaults to the latest."
    },
    "citation": {
      "type": "string",
      "description": "A citation (\"26 U.S.C. 61(a)\", \"40 CFR 60.1\", \"Pub. L. 119-21\", \"H.R. 1\", \"E.O. 14000\"). Give this or `path`."
    },
    "provision": {
      "type": "string",
      "description": "Part of the document: in a code section, a provision and everything under it (\"a-1\" for (a)(1)) or a run of them (\"a..c\"); in a law, bill or order, a heading's {#anchor} (\"tI-stA-s10101\") or a provision under it (\"tI-stA-s10101-a\")."
    }
  }
}

citations

Advertised by the server during the last successful anonymous check.

What cites a document: each corpus's citations of a code section, law, bill or order, with the words that cite it, and for a statute the regulations issued under it. Lists come 50 at a time; `list` and `offset` page through one.

citations input schema

{
  "type": "object",
  "properties": {
    "list": {
      "enum": [
        "code",
        "cfr-citations",
        "laws",
        "bills",
        "orders"
      ],
      "type": "string",
      "description": "One list only, by the corpus that cites."
    },
    "path": {
      "type": "string",
      "description": "A page of the site, as its path or full URL (\"/usc/26/61\", \"/pl/119/21\"). Give this or `citation`."
    },
    "offset": {
      "type": "integer",
      "default": 0,
      "description": "With `list`, where in it to start."
    },
    "citation": {
      "type": "string",
      "description": "A citation (\"26 U.S.C. 61(a)\", \"40 CFR 60.1\", \"Pub. L. 119-21\", \"H.R. 1\", \"E.O. 14000\"). Give this or `path`."
    }
  }
}

history

Advertised by the server during the last successful anonymous check.

How a document came to be: for a code section, the laws that enacted and amended it and every release that changed its text; for a law or bill, its legislative history, each version linked to its text and to what changed from the one before.

history input schema

{
  "type": "object",
  "properties": {
    "path": {
      "type": "string",
      "description": "A page of the site, as its path or full URL (\"/usc/26/61\", \"/pl/119/21\"). Give this or `citation`."
    },
    "citation": {
      "type": "string",
      "description": "A citation (\"26 U.S.C. 61(a)\", \"40 CFR 60.1\", \"Pub. L. 119-21\", \"H.R. 1\", \"E.O. 14000\"). Give this or `path`."
    }
  }
}

compare

Advertised by the server during the last successful anonymous check.

What changed in a code section between two releases: each provision added, removed, changed or renumbered, the edits marked <del> and <ins>. To compare versions of a bill, take the 'what changed' link from its history.

compare input schema

{
  "type": "object",
  "properties": {
    "to": {
      "type": "string",
      "description": "Release point or date to compare to. Defaults to the latest."
    },
    "from": {
      "type": "string",
      "description": "Release point or date to compare from. Defaults to the release before `to`."
    },
    "path": {
      "type": "string",
      "description": "A page of the site, as its path or full URL (\"/usc/26/61\", \"/pl/119/21\"). Give this or `citation`."
    },
    "citation": {
      "type": "string",
      "description": "A citation (\"26 U.S.C. 61(a)\", \"40 CFR 60.1\", \"Pub. L. 119-21\", \"H.R. 1\", \"E.O. 14000\"). Give this or `path`."
    },
    "only_edits": {
      "type": "boolean",
      "default": true,
      "description": "Only the provisions that changed, not the whole text."
    }
  }
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

90-day uptime

A lightweight connection check about every six hours, sampled on hosts with many listings. It shows the server answered, not that its tools work.

Too few checks for a percentage yet (1 of 1 answered).

2026-11-02: 1 of 1 checks answered

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks: 1 of 1 (100%)
Average latency: 667 ms
95th percentile latency: 667 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

Nov 1, 2026, 12:46 PM UTC · probe · passed · 667 ms · metadata changed · 5 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport sse us-codex-mcp-uscodex https://uscodex.org/mcp/sse

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).

Cline configuration

{
  "mcpServers": {
    "us-codex-mcp-uscodex": {
      "type": "sse",
      "url": "https://uscodex.org/mcp/sse",
      "disabled": false
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport sse us-codex-mcp-uscodex https://uscodex.org/mcp/sse

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