Skip to content
mcp/harbor
Verified official

501c3.HELP nonprofit compliance MCP

v0.1.1

help.501c3/compliance

Nonprofit compliance rules for all 50 US states, each with its official citation and status

transport:streamable-http tools:3
Website

Target client

run in your project directory 

claude mcp add --transport http compliance https://mcp.501c3.help/

setup guides: Claude Code Claude Desktop Cursor VS Code Zed Windsurf Cline Gemini CLI Grok ChatGPT Claude.ai LangChain

Adds it for this project only. Append --scope user to make it available everywhere. Claude Code docs

get_state_requirements Read-only

get state requirements

compare_states

compare states

get_filing_deadlines Read-only

get filing deadlines

All 3 tools, one page each

Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. Check the server's own documentation before granting access.