Connecting the eCFR MCP Server to Claude
Prerequisites
- A Claude Pro, Team, or Enterprise account at claude.ai
- The eCFR MCP Server running on Hugging Face Spaces
Step-by-Step Setup
1. Open Claude Settings
Go to claude.ai and click on your profile icon in the bottom-left corner, then select Settings.
2. Navigate to Connectors
In the Settings menu, click on Connectors in the left sidebar.
3. Add a Custom Connector
Click Add custom connector (or the + button).
4. Enter the MCP Endpoint URL
In the URL field, enter:
https://n8layman-ecfr-mcp-server.hf.space/gradio_api/mcp/sse
5. Save and Enable
Click Save. The connector should show as connected with 7 available tools.
6. Start Using It
Open a new conversation in Claude and ask a question about federal regulations. For example:
“What are the requirements for indirect cost rates under the Uniform Guidance?”
Claude will automatically use the eCFR tools to search and retrieve the relevant regulatory text.
Available Tools
Once connected, Claude has access to these 7 tools (prefixed with ecfr_mcp_server_ in Claude):
| Tool | What It Does |
|---|---|
| ecfr_mcp_server_ecfr_search | Search across all federal regulations by keyword |
| ecfr_mcp_server_ecfr_list_titles | List all 50 CFR titles |
| ecfr_mcp_server_ecfr_list_agencies | Find federal agencies and their regulation references |
| ecfr_mcp_server_ecfr_get_title_versions | Check amendment history and find valid dates |
| ecfr_mcp_server_ecfr_get_regulation | Retrieve the actual text of a regulation |
| ecfr_mcp_server_ecfr_get_title_structure | Browse the table of contents of a CFR title |
| ecfr_mcp_server_ecfr_compare_regulations | See what changed between two dates |
Set all tools to Always allow in the connector settings for the best experience.
Example Prompts
- “Search for regulations about informed consent in human subjects research”
- “What does 2 CFR 200.474 say about travel costs?”
- “Compare the Common Rule (45 CFR 46) between 2018 and 2024”
- “List all agencies related to health research”
- “What are the procurement standards under the Uniform Guidance?”
Troubleshooting
Connector won’t connect:
- Make sure the HF Space is running (visit the Space URL in a browser)
- The Space may need a moment to start up if it’s been idle
Rate limit errors:
- The eCFR API may throttle requests from shared IPs
- Consider duplicating the HF Space to get your own instance: click Duplicate this Space on the Space page
Tools not appearing:
- Try removing and re-adding the connector
- Refresh the Claude page