MCP Server Base v2.0 — Scale & Operability (2026)

Modern Model Context Protocol server using the latest stack:

• MCP SDK 1.12+ — McpServer high-level API + StreamableHTTPServerTransport (new) & StdioServerTransport

• TypeScript 5.7 ESM + NodeNext module

• Zod validation → auto JSON Schema + env validation (src/config.ts:1)

• Express 4 + helmet + CORS allowlist + rate-limit + health/ready + Admin UI

• Dual transport: STDIO (Claude Desktop) and Streamable HTTP (remote, 2025-03 spec, stateless + stateful resumability via RedisEventStore)

• Structured tool/resource/prompt modules + RAG (local vector), Web (cached), GitHub integrations

• OTEL tracing/metrics (src/utils/otel.ts:1), Tasks (experimental + create_task), k6 load tests

• tsx watch, vitest (130 tests, 91% coverage), graceful shutdown, docker-compose (redis, postgres, qdrant)

🚀 Quick Start

npm install
npm run build

# STDIO (for Claude Desktop, Cursor, opencode, etc.)
npm start

# HTTP (Streamable HTTP - latest)
npm run start:http
# → http://localhost:3000/mcp
# → health http://localhost:3000/health

Dev

npm run dev          # stdio watch
npm run dev:http     # http watch (Streamable HTTP at http://localhost:3000/mcp)
npm test             # unit + e2e (InMemory + HTTP)
npm run test:coverage # coverage 80% thresholds
npm run lint         # eslint 9 flat config
npm run format:check # prettier
npm run typecheck    # tsc --noEmit
npm run build

CI

.github/workflows/ci.yml runs on push/PR to main with Node 20+22 matrix: lint, format:check, typecheck, test:coverage, build, docker build.

Related MCP server: MCP Server

🔌 Transports

Streamable HTTP is the new standard replacing SSE (deprecated March 2025).

🧰 Tools (31)

📦 Resources (6)

• config://server-info — server metadata (JSON, now includes features)

• greeting://{name} — dynamic greeting template

• file:///{+path} — sandboxed file (ALLOWED_ROOT), list + complete, file:///notes.txt

• memory://{key} — memory KV, list + complete

• db://{table}/{id} — demo DB row (users/notes), list + complete

• docs://{id} — RAG chunk (ingested via rag_ingest), list + complete

💬 Prompts (4)

• code-review — args: language, code

• explain-concept — args: concept, level

• summarize — args: text, length (short/medium/long), style (bullets/paragraph/tldr)

• research — args: topic, depth (overview/deep), audience (beginner/expert/executive)

⚙️ Client Config

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "mcp-server-base": {
      "command": "node",
      "args": ["/absolute/path/to/mcp-server/dist/index.js"]
    }
  }
}

HTTP Client

import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
import { Client } from '@modelcontextprotocol/sdk/client/index.js';

const client = new Client({ name: 'my-client', version: '1.0.0' });
await client.connect(new StreamableHTTPClientTransport(new URL('http://localhost:3000/mcp')));
const tools = await client.listTools();

Inspector

npm run inspect
# or
npx @modelcontextprotocol/inspector node dist/index.js
npx @modelcontextprotocol/inspector http://localhost:3000/mcp

🐳 Docker

# Single container
docker build -t mcp-server-base .
docker run -p 3000:3000 --env TRANSPORT=http mcp-server-base

# Full stack (app + redis + postgres + qdrant) — see docker-compose.yml
docker compose up -d
docker compose logs -f app
# → http://localhost:3000/health, http://localhost:3000/mcp
# → redis :6379, postgres :5432, qdrant :6333

RAG Demo (ingest → search → docs://)

# via MCP tools (Inspector or Client)
# 1. ingest
rag_ingest { "text": "MCP is Model Context Protocol...", "id": "mcp-intro" }
# 2. search
rag_search { "query": "what is MCP?", "topK": 3 }
# 3. read resource
# docs://mcp-intro  → returns ingested text

📁 Structure

src/
├── index.ts              # entry: stdio + http (helmet/cors/rateLimit/auth/resumability)
├── server.ts             # createMcpServer() factory
├── config.ts             # zod env (AUTH, CORS, rateLimit, RAG, cache, integrations)
├── types.ts              # Zod schemas
├── middleware/auth.ts    # AUTH_MODE none|apiKey|bearer
├── middleware/rateLimit.ts
├── middleware/requestId.ts
├── utils/logger.ts       # stderr, JSON/text, redaction, child(requestId)
├── utils/eventStore.ts   # InMemoryEventStore for Last-Event-ID
├── utils/cache.ts        # MemoryCache (TTL) + defaultCache
├── utils/queue.ts        # SimpleQueue
├── tools/                # 31 tools: echo, fs, memory, db, shell, rag, web, github, elicitation, sampling, tasks
│   ├── filesystem.tool.ts, memory.tool.ts, database.tool.ts, shell.tool.ts
│   ├── rag.tool.ts, web.tool.ts, github.tool.ts, elicitation.tool.ts, sampling.tool.ts, tasks.tool.ts
├── resources/            # 6 resources: config, greeting, file, memory, db, docs
├── routes/admin.ts       # Admin UI + metrics + spans
└── prompts/              # 4 prompts: code-review, explain-concept, summarize, research

Add a new tool: create src/tools/my.tool.ts → export registerMyTool(server) → add to src/tools/index.ts.

🔐 Security (Phase 2)

• Helmet headers (x-dns-prefetch-control, x-frame-options, x-content-type-options, etc.) via helmet@7 (src/index.ts:1)

• CORS allowlist (CORS_ORIGIN=* or comma list) with cors credentials handling (src/config.ts:60)

• Auth AUTH_MODE=none|apiKey|bearer at src/middleware/auth.ts:1 — 401 without valid X-API-Key or Authorization: Bearer (health/ready & OPTIONS excluded)

• Rate limiting express-rate-limit (default 100/15min) on /mcp — 429 Too Many Requests (src/middleware/rateLimit.ts:1)

• RequestId (X-Request-Id randomUUID, echo header, child logger correlation) (src/middleware/requestId.ts:1)

• Zod env validation (src/config.ts:1) — parseEnv() validates PORT, AUTH_MODE, API_KEY cross-field, fails fast on invalid env

• Structured logger JSON/text, [REDACTED] for authorization, apiKey, token (src/utils/logger.ts:24)

• Resumability InMemoryEventStore (src/utils/eventStore.ts:1) + stateful session map when RESUMABILITY_ENABLED=true (replay via Last-Event-ID, GET /mcp stream, DELETE close)

• Docker hardening non-root appuser + HEALTHCHECK (Dockerfile:1)

• Tests: tests/unit/auth.test.ts, tests/unit/logger.test.ts, tests/unit/eventStore.test.ts, tests/e2e/security.test.ts (helmet/auth/rateLimit/resumability) — 67 tests → 130 total with Phase 5, 90.89% coverage

🔗 Integrations (Phase 4)

• Cache MemoryCache TTL (src/utils/cache.ts:1) — defaultCache for web/github, SimpleQueue (src/utils/queue.ts:1)

• RAG local vector (hash embedding 128-dim, cosine, chunk 500/50) at src/tools/rag.tool.ts:1 — rag_ingest (chunked + sendResourceListChanged), rag_search (topK, threshold), rag_list, rag_clear + docs://{id} resource

• Web src/tools/web.tool.ts:1 — brave_search (mock if no BRAVE_API_KEY), tavily_search (mock), web_fetch (cached via defaultCache, CACHE_TTL_MS)

• GitHub src/tools/github.tool.ts:1 — github_search_repos, github_get_repo, github_get_issue (cached, GITHUB_TOKEN for rate limit)

• Stack docker-compose.yml:1 (app + redis:7 + postgres:16 + qdrant:v1.12.4) with healthchecks

• Demo rag_ingest → rag_search → docs:// E2E verified in tests/integrations.test.ts:1 (21 tests)

📈 Scale & Operability (Phase 5 — v2.0)

• Versioned MCP v2.0.0 (package.json:1, config.MCP_SERVER_VERSION) with instructions per minor (src/server.ts:1)

• OTEL tracing/metrics (src/utils/otel.ts:1) — createSpan/withSpan, incrementCounter/recordHistogram, getMetrics/getSpans, JSON export stub for OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_ENABLED flag

• RedisEventStore (src/utils/redisEventStore.ts:1) — EventStore impl with storeEvent/replayEventsAfter, in-memory fallback, eventStoreFactory.create() for horizontal scale (EVENT_STORE_TYPE=memory|redis, REDIS_URL)

• Admin UI (src/routes/admin.ts:1) — GET /admin (HTML dashboard), /admin/tools|resources|prompts|metrics|spans|stores|health (JSON), protected via ADMIN_TOKEN (X-Admin-Token), ADMIN_ENABLED flag

• Tasks (src/tools/tasks.tool.ts:1) — experimental delay_task (if SDK tasks available) + fallback create_task/get_task/get_task_result (in-memory, polling), SimpleQueue/MemoryCache infra

• Bench k6/load.js:1 — http_req_duration p(95)<100ms, stages 10→50 VUs, checks >99%, npm run bench / bench:local

• Compose docker-compose.yml:1 already includes redis/postgres/qdrant for scale

• Tests: tests/scale.test.ts:1 (OTEL spans/metrics, RedisEventStore replay, cache TTL, queue, admin HTML/metrics/token/ready, tasks create/poll, version, k6 script) — 130 total

• Deploy ready for Fly.io/Cloud Run (stateless + RedisEventStore), GHCR via release.yml, npm 2.0.0

• Logger stderr-safe, never logs secrets (redaction)

• Zod → JSON Schema via SDK (src/types.ts:1, src/tools/*.tool.ts)

• Timeout on fetch (10s) + structured errors

• Graceful shutdown (SIGINT/SIGTERM)

• Health (GET /health) & ready (GET /ready) separate from MCP

• Stateless default (sessionIdGenerator: undefined), stateful when RESUMABILITY_ENABLED=true (src/index.ts:22)

• Type-safe, strict TS + ESLint flat + Prettier + husky + lint-staged

• Coverage 85% lines / 70% branches enforced (vitest.config.ts:1), 130 tests: unit + e2e HTTP/security/capabilities/integrations/scale

🤝 Contributing

See CONTRIBUTING.md — nvm use, npm test, add tool/resource/prompt, ensure lint/typecheck/test pass. See CODE_OF_CONDUCT.md.

📚 MCP Docs

• Spec: https://spec.modelcontextprotocol.io

• SDK: https://github.com/modelcontextprotocol/typescript-sdk

• Inspector: https://github.com/modelcontextprotocol/inspector