Regulation Reader MCP in Claude: Install Guide, Live Test

Questions it answers

Read a CFR or eCFR section, or search US federal regulations and the Federal Register. Ask "what does 21 CFR 11.10 say?", "which regulations mention respirator fit testing?" or "what has the FDA proposed on food dyes this year?".

Regulation Reader reads two official United States sources directly: the Electronic Code of Federal Regulations (eCFR) for the current text of any section of the Code of Federal Regulations, and the Federal Register for the rules, proposed rules, notices and presidential documents the agencies publish each day. It is an independent tool, not a government service.

A section lookup returns the citation, heading, full text, statutory authority and amendment history of the section, with the date the eCFR is up to date as of and a link to the section. A very long section is cut and says so. A search returns the matching sections or documents with the agency, the publication date, the comment deadline and effective date where there is one, and the CFR parts a document changes.

This is general information, not legal advice. The eCFR is an unofficial edition kept up to date by the Office of the Federal Register; the legal text is the Federal Register and the annual CFR. A rule applies differently to each situation, so check the current official text and ask a qualified lawyer before you rely on it.

It covers United States federal regulations only: not state or local law, court decisions, statutes, other countries' rules or guidance documents that are not in the Federal Register.

It stores nothing about you: answers are cached for up to six hours (sections) or an hour (searches), and the only lasting record is a daily count of calls per tool.

Short questions this server answers, each with a direct answer: Look up US federal regulations and Federal Register rules.

What it can do

Reads the current text of any section of the US Code of Federal Regulations (eCFR)
Shows a section's heading, statutory authority and amendment history with a link
Searches the current regulations by words, in one title or all of them
Searches the Federal Register for rules, proposed rules, notices and executive orders
Shows comment deadlines, effective dates and the CFR parts a document changes

Tools

get_cfr_section, Read a CFR section. Use this when the user asks what a specific US federal regulation says, including an FDA, OSHA, EPA, SEC, FTC or FAA section of the eCFR, for example "what does 21 CFR 11.10 say?", "read 29 CFR 1910.134" or "show me 17 CFR 240.10b-5". Pass the CFR title number and the section number. Returns the current text, heading, statutory authority and amendment history of the section, the date the eCFR is up to date as of and a link to it. A very long section is cut at a paragraph and flagged with nextOffset; call again with that offset to read on. This is general information, not legal advice. Do not use it to find a regulation by topic (use search_cfr), for statutes, state law or court decisions, or to decide whether someone complies.
search_cfr, Search the CFR. Use this when the user asks which US federal regulations or compliance rules cover a topic, including an OSHA, EPA or FDA rule, for example "which regulations mention respirator fit testing?", "find the rules on electronic signatures in title 21" or "where does the CFR define small business?". Pass 2 to 4 words and, if known, the CFR title to search in. A section must hold every word; when nothing does, the search drops the last words and says which query matched (matchedQuery). Returns the best matching sections with citation, heading, an excerpt, the agency and a link; use get_cfr_section to read one in full. This is general information, not legal advice. Do not use it for recent rulemaking news (use search_federal_register), statutes, state law or court decisions.
search_federal_register, Search the Federal Register. Use this when the user asks what federal agencies have published, proposed or announced, including a rulemaking, for example "what has the FDA proposed on food dyes?", "find final rules on noncompete agreements" or "which executive orders mention AI this year?". Pass the words to find and optionally the document type (rule, proposed_rule, notice, presidential_document) and a publication date range. Returns each document's title, type, agencies, publication date, abstract, effective date, comment deadline, the CFR parts it changes and a link. This is general information, not legal advice. Do not use it to read the current text of a regulation (use get_cfr_section), or for state law, bills, court decisions or non-US rules.

Add Regulation Reader in Claude

Claude connects to a remote MCP server as a custom connector. The connection is made from Anthropic's cloud, not from your laptop, so the server must be on the public internet. Regulation Reader is. These steps were checked against Claude's custom-connector article (updated 2026-08-11) and the Claude Code MCP docs on 2026-10-01.

On a Pro or Max plan:

Open Customize, then Connectors.
Select the plus button, then Add custom connector.
Paste this URL. Leave Advanced settings empty: this server does not need an OAuth client id or secret.
```
https://rules.openkrill.app/mcp
```
Select Add. The connector is yours. Anthropic has not reviewed it, and it is not a Directory listing.
In a conversation, open the plus button, then Connectors, and enable Regulation Reader. Ask: What does 21 CFR 11.10 say about electronic records controls?

On Team and Enterprise, an Owner adds the connector first at Organization settings, then Connectors, then Add, then Custom, then Web, and pastes the same URL. Members then connect it from Customize. A Free plan can add one custom connector.

In Claude Code, add it from the project directory:

claude mcp add --transport http rules https://rules.openkrill.app/mcp

That writes a local or user config. A JSON entry needs "type": "http" (or streamable-http) plus the url. An entry with a url and no type is skipped. Confirm with claude mcp get rules. The tools you should see are get_cfr_section, search_cfr, search_federal_register.

If Claude tries to fetch https://rules.openkrill.app/mcp from its code sandbox and reports HTTP 403, the block is Claude's sandbox network allowlist, not this server. The sandbox proxy answers 403 with x-deny-reason: host_not_allowed for every host outside the allowlist. Use the connector above instead: connector calls come from Anthropic's cloud and do not pass the sandbox proxy. To let the sandbox reach it as well, an Owner adds rules.openkrill.app under Settings, then Capabilities, then Additional allowed domains.

Enable the connector only in conversations that need it. Claude can call the tools while you work, including during research, so turn off any tool you do not want invoked. Regulation Reader does not write to your accounts. It still receives the arguments of each call. Read the privacy page before you paste anything that is not public.

If it does not work

The tool does not show up

In Claude, enable the connector in the conversation from the plus button, then Connectors. In Claude Code, run claude mcp list from the same directory you added it in, then start a new session: a running session does not load a new server.

429 or rate_limited

Each server takes 60 calls a minute from one network, and some tools take fewer. Past that the call comes back as a tool error that starts with rate_limited: wait a minute and ask again. daily_limit means the server reached its shared daily cap, which resets at 00:00 UTC. A limit is not an answer, so do not read it as no results. For higher limits, ask support@openkrill.app for a key.

JSON entry has no type

Claude Code skips an entry in .mcp.json that has a url but no type. Add "type": "http" next to the url, or add the server with claude mcp add --transport http, which writes the type for you. The VS Code entry needs the same type field. Cursor and Pi read the url alone.

A call checked on 2026-10-17

21 CFR 11.10 is the electronic-records section named in the plugin's starter prompts. The request below was posted to https://rules.openkrill.app/mcp as tools/call. HTTP 200. Source: the Regulation Reader server, read 2026-10-17.

{
  "method": "tools/call",
  "params": {
    "name": "get_cfr_section",
    "arguments": {
      "title": 21,
      "section": "11.10"
    }
  }
}

asOf. 2026-10-15
source. Electronic Code of Federal Regulations (eCFR, ecfr.gov), Office of the Federal Register
heading. Controls for closed systems.
citation. 21 CFR 11.10
notice. The eCFR is an unofficial, continuously updated edition of the Code of Federal Regulations. The legal text is the Federal Register and the annual CFR on govinfo.gov. This is general information, not legal advice. Regulat
url. https://www.ecfr.gov/current/title-21/section-11.10

Repeat the call yourself if you need a newer reading. Cached answers expire. A rate limit is not a result: wait and try again. Nothing in the call is a ranking, a filing, or advice.

Using it in production

Nothing to install and nothing to run: no package, no Python or Node.js version and no environment variable. Regulation Reader runs on our servers, and your client only needs the URL https://rules.openkrill.app/mcp.

Rate limit	60 tool calls a minute from one network. `initialize` and `tools/list` do not count.
Daily cap	25000 tool calls a day per server, shared by every caller. It resets at 00:00 UTC.
At a limit	The call comes back as a tool error that starts with `rate_limited` (wait a minute) or `daily_limit` (try after 00:00 UTC), never as a partial answer.
Key	None. Do not add an `Authorization` header or a key field.
Higher limits	Email support@openkrill.app with the server name, the calls a day you expect and what they are for. We answer within 1 business day.
Freshness	Some answers come from a short cache. Each guide shows the date of its checked call; repeat a call when you need a newer reading.
Uptime	Scheduled test calls check the servers through the same endpoint. There is no SLA yet.
Data	What each server receives and keeps is on the privacy page.

Use it in other apps

Roles that use Regulation Reader

Compliance reader guide

Frequently asked questions

How do I install the Regulation Reader MCP server in Claude?

In Claude, open Customize, then Connectors, choose Add custom connector and paste https://rules.openkrill.app/mcp. In Claude Code, run claude mcp add --transport http rules https://rules.openkrill.app/mcp. No restart is needed for either.

Do I need an API key to run Regulation Reader in Claude?

No. This server takes no API key. For higher limits, email support@openkrill.app with the server name (Regulation Reader), the calls a day you expect and what they are for. We answer within 1 business day.

What should I do if Regulation Reader does not connect in Claude?

Check that the connector URL ends in /mcp and that Advanced settings are empty. In Claude Code, run claude mcp get rules; a JSON entry with a url but no type is skipped, so add type http.

Words on this page

Source: plugin listing for rules in this repository, and a live tools/call on 2026-10-17. As of 2026-10-17.