eCFR MCP

What is eCFR MCP?

eCFR MCP is a Model Context Protocol server that wraps the Electronic Code of Federal Regulations (eCFR) API into deterministic tool calls. It is built for federal contracting officers, attorneys, compliance teams, and regulatory analysts who need current or historical CFR text, including FAR, DFARS, and agency FAR supplements.

How to use eCFR MCP?

Install via pip install ecfr-mcp or run directly with uvx ecfr-mcp. Configure the server in your MCP client using JSON (Claude Desktop), TOML (Codex), or platform-specific settings (Gemini CLI, Copilot, VS Code, etc.). No API key is required; simply add the provided configuration block to your client’s MCP server list.

Key features of eCFR MCP

• 13 tools covering full CFR text and structure
• Current text retrieval for any title, chapter, or section
• Full-text search across the entire CFR
• Version history and side-by-side section comparison
• Point-in-time lookups for historical regulatory text
• FAR-specific clause and definition lookup tools
• No API key required; MIT licensed

Use cases of eCFR MCP

• Look up exact FAR clause text for a contract file or write-up
• Build defensible compliance memos citing current and prior CFR text
• Track when a FAR/DFARS section was amended and what it said before
• Compare current FAR text to what was in force at award for protest defense
• Pull definitions from FAR 2.101 and DFARS 202.101 with surrounding context

FAQ from eCFR MCP

What tools does eCFR MCP provide?

It includes 13 tools: get_cfr_content, get_cfr_structure, search_cfr, get_version_history, compare_versions, find_recent_changes, lookup_far_clause, find_far_definition, get_corrections, list_agencies, get_ancestry, list_sections_in_part, and get_latest_date.

Does eCFR MCP require an API key?

No. The server accesses the public eCFR API with no authentication needed.

Which MCP clients are compatible?

Claude Desktop, Codex (ChatGPT), Gemini CLI, Copilot, Claude Code, Cursor, Cline, Zed, Continue, and any other MCP-compatible client.

How is the server hardened?

It has been live-audited against the production eCFR API across multiple rounds, handling XML parsing, historical date resolution, version diffs, and pagination. Pydantic models use extra="forbid" to surface schema drift.

What CFR content is covered?

All titles of the Code of Federal Regulations, including FAR (48 CFR Chapter 1), DFARS (48 CFR Chapter 2), and all agency FAR supplements such as NFS, AFFARS, AFARS, NMCARS, DARS, DOSAR, HHSAR, EPAAR, and IAAR.