Us MCP Server

US law MCP: bills, US Code, Federal Register, executive orders, case law (state+federal), eCFR

Local serverstdioPython

What is the Us MCP server?

Us MCP server exists for a simple reason — assistants are far more useful when they can act on Us directly instead of describing what you should do. US law MCP: bills, US Code, Federal Register, executive orders, case law (state+federal), eCFR.

What you get

MCP server for US law with verifiable citations. Five sources behind ten read-only tools:

Setting it up

The server ships on PyPI as us-eli-mcp, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

What the assistant can call

Once Us is connected, these are the calls the assistant has available:

  • us_search_bills — List bills by congress (e.g. 118) and type (hr, s, hres, ...)
  • us_get_bill — Full detail + latest action for one bill
  • us_list_code_packages — List GovInfo packages in a collection (USCODE, CFR, FR, STATUTE)
  • us_get_code_package — Metadata + download links (PDF/XML/TXT) for one package
  • us_search_federal_register — Full-text search over FR documents; filter rules, notices, executive orders
  • us_get_federal_register_doc — One FR document with its official citation (e.g. 91 FR 41591)
  • us_search_case_law — Full-text search over 8M+ opinions; court filter (e.g. cal, ny, scotus)
  • us_get_case — One opinion cluster by cluster_id
  • us_search_cfr_sections — Full-text search over the current CFR (eCFR)
  • us_get_cfr_section_history — Amendment history of one CFR section (e.g. 15 CFR 744.3)

Configuration and credentials

You will need 8 environment variables: US_ELI_API_KEY, DEMO_KEY, US_ELI_GOVINFO_API_KEY, US_ELI_BASE_URL, US_ELI_GOVINFO_BASE_URL, US_ELI_FR_BASE_URL, US_ELI_COURTLISTENER_BASE_URL, US_ELI_ECFR_BASE_URL. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

Before you rely on it

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • With 10 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Us.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the us mcp server does with a few real requests.

Choosing this one

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Us's toolset — us_search_bills, us_get_bill, us_list_code_packages and 7 more — is a fair guide to whether it matches your workflow. It is maintained by matematicsolutions; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Us's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Available tools

ToolWhat it does
us_search_billsList bills by congress (e.g. 118) and type (hr, s, hres, ...)
us_get_billFull detail + latest action for one bill
us_list_code_packagesList GovInfo packages in a collection (USCODE, CFR, FR, STATUTE)
us_get_code_packageMetadata + download links (PDF/XML/TXT) for one package
us_search_federal_registerFull-text search over FR documents; filter rules, notices, executive orders
us_get_federal_register_docOne FR document with its official citation (e.g. 91 FR 41591)
us_search_case_lawFull-text search over 8M+ opinions; court filter (e.g. cal, ny, scotus)
us_get_caseOne opinion cluster by cluster_id
us_search_cfr_sectionsFull-text search over the current CFR (eCFR)
us_get_cfr_section_historyAmendment history of one CFR section (e.g. 15 CFR 744.3)

How to install the Us MCP server

{
  "mcpServers": {
    "us-eli": {
      "command": "uvx",
      "args": ["us-eli-mcp"],
      "env": {
        "US_ELI_API_KEY": "your-value",
        "DEMO_KEY": "your-value",
        "US_ELI_GOVINFO_API_KEY": "your-value",
        "US_ELI_BASE_URL": "your-value",
        "US_ELI_GOVINFO_BASE_URL": "your-value",
        "US_ELI_FR_BASE_URL": "your-value",
        "US_ELI_COURTLISTENER_BASE_URL": "your-value",
        "US_ELI_ECFR_BASE_URL": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

VariableDescriptionRequired
US_ELI_API_KEYCredential the server authenticates with.Yes
DEMO_KEYCredential the server authenticates with.Yes
US_ELI_GOVINFO_API_KEYCredential the server authenticates with.Yes
US_ELI_BASE_URLEndpoint or connection string the server talks to.Yes
US_ELI_GOVINFO_BASE_URLEndpoint or connection string the server talks to.Yes
US_ELI_FR_BASE_URLEndpoint or connection string the server talks to.Yes
US_ELI_COURTLISTENER_BASE_URLEndpoint or connection string the server talks to.Yes
US_ELI_ECFR_BASE_URLEndpoint or connection string the server talks to.Yes

Example prompts to try

  • Use Us to us search bills.
  • Use Us to us get bill.
  • Use Us to us list code packages.

Frequently asked questions

It connects Us to MCP-compatible AI assistants such as Claude and Cursor, exposing 10 tools (us_search_bills, us_get_bill, us_list_code_packages, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Us directly.