┌─────────────────────────┐
│  Markdown / PDF         │  Display & Sharing
├─────────────────────────┤
│  Translation            │  Explanation & Verification
├─────────────────────────┤
│  RFCXML MCP             │  Common Understanding for AI & Humans
├─────────────────────────┤
│  RFCXML                 │  Single Source of Truth
└─────────────────────────┘

{
  "mcpServers": {
    "rfcxml": {
      "command": "npx",
      "args": ["-y", "@shuji-bonji/rfcxml-mcp"]
    }
  }
}

npm install -g @shuji-bonji/rfcxml-mcp

{
  "mcpServers": {
    "rfcxml": {
      "command": "rfcxml-mcp"
    }
  }
}

{
  "rfc": 6455,
  "sections": [...],
  "_source": "text",
  "_sourceNote": "Warning: Parsed from text format. Accuracy may be limited."
}

{
  "metadata": {
    "title": "Transmission Control Protocol (TCP)",
    "docName": "draft-ietf-tcpm-rfc793bis-28",
    "number": 9293
  },
  "sections": [
    {
      "number": "section-1",
      "title": "Purpose and Scope"
    },
    {
      "number": "section-3",
      "title": "Functional Specification",
      "subsections": [
        { "number": "section-3.1", "title": "Header Format" },
        {
          "number": "section-3.5",
          "title": "Establishing a Connection",
          "subsections": [
            { "number": "section-3.5.1", "title": "Half-Open Connections and Other Anomalies" },
            { "number": "section-3.5.2", "title": "Reset Generation" }
          ]
        }
      ]
    }
  ],
  "referenceCount": { "normative": 15, "informative": 85 },
  "_source": "xml"
}

{
  "rfc": 9293,
  "filter": { "level": "MUST" },
  "stats": { "total": 53, "byLevel": { "MUST": 53 } },
  "requirements": [
    {
      "id": "R-section-3.5-5",
      "level": "MUST",
      "text": "A TCP implementation support simultaneous open attempts (MUST-10).",
      "section": "section-3.5",
      "sectionTitle": "Establishing a Connection"
    },
    {
      "id": "R-section-3.7.1-9",
      "level": "MUST",
      "text": "TCP endpoints implement both sending and receiving the MSS Option (MUST-14).",
      "section": "section-3.7.1",
      "sectionTitle": "Maximum Segment Size Option"
    }
  ],
  "_source": "xml"
}

{
  "rfc": 9293,
  "normative": [
    { "rfcNumber": 791, "title": "Internet Protocol", "anchor": "RFC0791" },
    { "rfcNumber": 2119, "title": "Key words for use in RFCs to Indicate Requirement Levels" },
    { "rfcNumber": 5681, "title": "TCP Congestion Control" }
  ],
  "informative": [
    { "rfcNumber": 793, "title": "Transmission Control Protocol" },
    { "rfcNumber": 1122, "title": "Requirements for Internet Hosts - Communication Layers" }
  ],
  "_source": "xml"
}

# RFC 9293 Implementation Checklist

**Transmission Control Protocol (TCP)**

Role: Client

## Required (MUST / REQUIRED / SHALL)

- [ ] A TCP implementation support simultaneous open attempts (MUST-10). (section-3.5)
- [ ] TCP endpoints implement both sending and receiving the MSS Option (MUST-14). (section-3.7.1)
- [ ] The RTO be computed according to the algorithm in, including Karn's algorithm (MUST-18). (section-3.8.1)

## Optional (MAY / OPTIONAL)

- [ ] Implementers include "keep-alives" in their TCP implementations (MAY-5). (section-3.8.4)

{
  "metadata": {
    "title": "The WebSocket Protocol",
    "number": 6455
  },
  "sections": [
    { "number": "1", "title": "Introduction" },
    { "number": "5", "title": "Data Framing" }
  ],
  "_source": "text",
  "_sourceNote": "Warning: Parsed from text format. Accuracy may be limited."
}

Generate an implementation checklist for RFC 9293 (TCP).

src/
├── index.ts                    # MCP server entry point
├── config.ts                   # Centralized configuration
├── constants.ts                # BCP 14 keyword definitions + RFC number limits
├── services/
│   ├── rfc-fetcher.ts          # RFC fetching (parallel)
│   ├── rfc-service.ts          # RFC parse & cache management
│   ├── rfcxml-parser.ts        # RFCXML parser
│   ├── rfc-text-parser.ts      # Text fallback parser
│   └── checklist-generator.ts  # Checklist generation service
├── tools/
│   ├── definitions.ts          # MCP tool definitions
│   └── handlers.ts             # Tool handlers (toolHandlers map)
├── types/
│   └── index.ts                # Type definitions
└── utils/
    ├── cache.ts                # LRU cache
    ├── fetch.ts                # Parallel fetch utility
    ├── logger.ts               # Logger abstraction
    ├── requirement-extractor.ts # Shared requirement extraction
    ├── section.ts              # Section search utilities
    ├── statement-matcher.ts    # Weighted statement matching
    ├── text.ts                 # Text processing utility
    └── validation.ts           # Input validation

┌─────────────────┐
│  fetchRFCXML()  │
└────────┬────────┘
         │ Parallel requests
    ┌────┴────┬────────────┐
    ▼         ▼            ▼
┌────────┐ ┌────────┐ ┌────────┐
│RFC     │ │IETF    │ │Data-   │
│Editor  │ │Tools   │ │tracker │
└────┬───┘ └────┬───┘ └────┬───┘
     │          │          │
     └────┬─────┴──────────┘
          │ Promise.any (first success)
          ▼
    ┌───────────┐
    │ Successful│ → Cancel other requests via AbortController
    │ Response  │
    └───────────┘

# Install dependencies
npm install

# Development mode
npm run dev

# Build
npm run build

# Test (watch mode)
npm test

# Test (single run — for CI etc.)
npm test -- --run

# E2E test (MCP client integration)
npm run test:e2e

# Lint
npm run lint

# Format
npm run format