Zucca
Cited answers from Title 21 of the Code of Federal Regulations (21 CFR), inside Claude, ChatGPT or any MCP client. No sign-up and no API key. Built by Zucca.
What it does
Five read-only tools over 21 CFR. Every result carries its section citation and a link to the official text on eCFR, so you can check the answer yourself.
| Tool | What it does |
|---|---|
regulations_search | Finds the passages that best answer a question, matching both its words and its meaning |
regulations_browse | Lists the parts held, or every section in a part, with headings |
regulations_getSection | Reads a whole section, or one paragraph of it, in order |
regulations_getCitation | Reads one passage by the exact id another tool returned |
regulations_findText | Finds passages that contain an exact phrase |
Coverage: 21 CFR chapter I, subchapters A (General) and B (Food for Human Consumption, including part 190, Dietary Supplements), and chapter II parts 1300 (Definitions) and 1308 (Schedules of controlled substances). Part 1300 says a botanical dietary ingredient that is not anabolic or androgenic is not an anabolic steroid, and part 1308 holds the hemp exclusions. Every response names the parts and edition it searched. A rule outside those parts will not be found.
Connect it
Server URL:
https://mcp.zucca.ai/mcp
Claude: Settings → Connectors → Add custom connector, paste the server URL and leave authentication off.
ChatGPT: Plugins → + → Add custom MCP server, enter the server URL and choose no authentication.
Other MCP clients: add the server URL as a Streamable HTTP server, with no authentication.
Try it
“What does 21 CFR require for declaring added sugars on the Nutrition Facts label? Cite the paragraphs.”
“What is the reference amount customarily consumed for breakfast cereals? Give the citation.”
“List every section in 21 CFR part 101 that covers health claims.”
“Does 21 CFR use the exact phrase “good source”? Show me where.”
Tips for good answers
• Ask in regulatory words where you can: “reference amount customarily consumed” works better than “serving size”.
• Ask the assistant to read the whole section. Exceptions often sit next to the rule they change.
• For “how many” or “list every” questions, ask it to browse the part rather than search.
Limits
• It returns regulation text, not legal advice. Check the official text on eCFR before you rely on an answer.
• It covers the parts listed above only, and our copy can lag the official text.
• Requests are rate-limited per IP address to keep the service fair to everyone.
Troubleshooting
• “Not found” for a section: the section may be outside the parts we hold. The error names the parts we do hold.
• No search results: an empty result does not prove a rule does not exist. Try other words, or browse the part.
• “Too many requests”: wait a minute and try again.
• Can’t connect: check the URL is exactly https://mcp.zucca.ai/mcp, with no trailing slash, and that authentication is off.