Search and read US Code, regulations, bills, laws and executive orders with cross-links and version history.
Access the full text of federal law including the United States Code, Code of Federal Regulations, Public Laws, Congressional Bills, and Executive Orders. Search across all corpora, read documents with legislative history, compare versions, and find what cites each provision.
Try asking Muse: "Show me how the tax code section on income has changed over the past five years."
Source: Found in the official MCP Registry (org.uscodex/uscodex) · First listed September 25, 2026
Each bar is one check, every 15 minutes. Green means it answered. Last checked 2 h ago.
What Muse can see: It does not ask you to sign in, so it cannot see your accounts. It only sees what Muse sends it from your request.
Before it acts: Read what Muse plans to do before you approve it, and remove the app from Muse when you stop using it.
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Not in Muse's Connectors list yet, but Muse can still use it. Copy the request below and paste it into Muse. Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
https://uscodex.org/mcpNot in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
US Codex is a remote MCP server, so any assistant that can add a custom connector by link can use it. Same link, same tools.
In ChatGPT, open Settings, then Connectors (called Apps & Connectors on some accounts).
Under Advanced settings, switch on Developer mode. That is what lets you add a connector by link.
Choose Create, give it a name, paste the link as the MCP server URL, and save. If it needs a sign-in, ChatGPT asks for it here.
Start a chat, open the tools menu, pick the connector, and ask. ChatGPT asks before it runs a tool the first time.
Custom connectors need a paid ChatGPT plan, and on Team, Enterprise and Edu accounts only an admin can add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in ChatGPT
In Claude, open Settings, then Connectors.
Choose Add custom connector, give it a name, and paste the link.
If it needs a sign-in, Claude sends you to it. Then turn the connector on in a chat from the tools menu and ask.
Custom connectors are available on paid Claude plans; on Team and Enterprise accounts an admin may need to add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in Claude
https://uscodex.org/mcpResponse time at the last check: 535ms. Worked in 99.1% of checks over 30 days.
Screened, no issues found
Screening looks for known threats and hidden instructions at the time of the check, and runs again weekly and whenever the tool list changes. It cannot see the server's code, so only connect what you need and review what Muse asks to do. How screening works.
searchSearch 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 onfetchRead 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 citationsWhat 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.historyHow 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.compareWhat 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.https://uscodex.org/mcpNot in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use US Codex to help me. It is a free service with an MCP server at https://uscodex.org/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
At the last check (November 13, 2026, 12:46 UTC) the endpoint was working, answering in 535ms. Over the last 7 days it answered 100% of health checks. It is checked every 15 minutes.
It was screened on September 25, 2026 with the result "screened, no issues found". Screening checks the domain against threat feeds and reads the tools for hidden instructions and requests for passwords or card numbers. It cannot see the server's code, so grant only the access you need.
It exposes 5 tools, including search, fetch, citations, history. For example, you could ask Muse: "Show me how the tax code section on income has changed over the past five years."
This listing was added from public sources (Found in the official MCP Registry (org.uscodex/uscodex)). If you build US Codex, claim it to correct the details and get your badge.
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