regulationsgov-mcp

Free, open-source MCP server for the Regulations.gov API. Federal rulemaking dockets, proposed rules, final rules, public comments, and comment period tracking.

Optional free API key for higher rate limits. Use the installation and configuration instructions below to connect this MCP directly.

Tested and hardened through five rounds of integration testing against the live Regulations.gov API, including a round-7 independent re-audit with live verification. 197 regression tests covering 1 P0 catastrophic bug, 10 P1 silent-wrong-data bugs (including agency_id="" returning all 1,951,938 records), 7 P2 validation gaps, and 12 round-7 findings fixed. See testing.md for the full testing record.

Available in Claude and ChatGPT

A hosted edition is coming soon to the Claude and ChatGPT directories. It will need no API key and no local setup. Locally, a free personal key is recommended; a shared fallback works at low volume. Until the listings are live, use the installation and configuration instructions below, then try a matching prompt.

What it does

Exposes the Regulations.gov API plus a credential-readiness check as 9 MCP tools:

Core

• search_documents - Search proposed rules, final rules, notices with flexible filters
• get_document_detail - Full document details with optional attachments
• search_comments - Search public comments (by docket, document, or keyword)
• get_comment_detail - Full comment text and submitter info
• search_dockets - Search rulemaking and nonrulemaking dockets
• get_docket_detail - Docket metadata, abstract, and RIN

Workflow

• open_comment_periods - Currently open comment periods across procurement agencies
• far_case_history - Full lifecycle of a FAR/DFARS rulemaking case

Get your own API key (strongly recommended)

This server hits api.regulations.gov, which uses api.data.gov for rate limiting.

• Without a key: falls back to the shared DEMO_KEY which is capped at ~10 requests per hour (live-measured) across everyone using it, so you'll hit 429 errors within a couple of prompts.
• With a personal key: 1,000 requests per hour, yours alone.

Get a free key (takes 30 seconds):

1. Go to open.gsa.gov/api/regulationsgov/#getting-started (or directly at api.data.gov/signup)
2. Enter your name and email: no approval, no wait
3. Copy the key from the confirmation page
4. Paste it into your client config as REGULATIONS_GOV_API_KEY (see below)

The same api.data.gov key works for every api.data.gov-backed API (Regulations.gov, GSA Per Diem, NASA, FEC, FCC, etc.), so if you already have one for another 1102tools MCP you can reuse it.

Installation

uvx regulationsgov-mcp

Configuration

Use the configuration below as the server definition and adapt its placement to your compatible MCP client. For practical requests using this source, see the prompt library.

Recommended (with your own key):

{
  "mcpServers": {
    "regulationsgov": {
      "command": "uvx",
      "args": ["--refresh-package", "regulationsgov-mcp", "--from", "regulationsgov-mcp", "regulationsgov-mcp"],
      "env": {
        "REGULATIONS_GOV_API_KEY": "paste-your-api-data-gov-key-here"
      }
    }
  }
}

Without a key (works for a handful of calls per hour, then 429s until the hour rolls over):

{
  "mcpServers": {
    "regulationsgov": {
      "command": "uvx",
      "args": ["--refresh-package", "regulationsgov-mcp", "--from", "regulationsgov-mcp", "regulationsgov-mcp"]
    }
  }
}

The --refresh-package flag tells uv to check PyPI for a newer release each time your client launches the server, so fixes arrive automatically; without it, uv keeps serving whatever version it first cached. It adds a moment of network time at startup, so raise your platform's MCP startup timeout if it enforces a short one.

Restart the client and the tools appear.

Example prompts

• "What FAR cases have open comment periods right now?"
• "Show me the full docket history for FAR-2023-0008."
• "Find all proposed rules from DARS posted in the last 6 months."
• "How many public comments were submitted on FAR Case 2023-008?"
• "Search for rulemaking dockets related to cybersecurity at DoD."
• "Find all SBA rules about size standards from the last year."

Important: case-sensitive filter values

Regulations.gov filter values are CASE-SENSITIVE. Use exact casing:

• Document types: Proposed Rule, Rule, Notice (not lowercase)
• Docket types: Rulemaking, Nonrulemaking
• Lowercase values silently return 0 results with no error

Companion tools

• federal-register-mcp: what was published in the Federal Register
• regulationsgov-mcp: the docket structure, public comments, and comment period status
• ecfr-mcp: what the regulation currently says after amendments

Together these three cover the full regulatory pipeline from proposal through public comment to codified rule.

Request pacing

The next request starts after the previous request's duration plus 4 seconds. This is a completion delay, not a 4-second start interval. Local processes sharing the same pacing directory and identity share this gate; a separate local counter does not create additional provider quota.

See the complete pacing reference for all nine servers, shared credentials/IPs, configuration and hosting differences.

Every request and pagination subrequest uses a provisional 4-second cross-process anti-burst interval by default. Regulations.gov and Per Diem share a local api.data.gov bucket when they use the same key. This does not increase provider quota or coordinate the key on another computer. Override with FEDERAL_API_MIN_INTERVAL_SECONDS, use 0 to deliberately disable it, and use FEDERAL_API_PACING_DIR to relocate local pacing state.

License

MIT