How I Built 9 MCP Servers with 49 Tools on Cloudflare Workers Edge

#mcp #ai #showdev #tooling

The MCP (Model Context Protocol) ecosystem is growing fast. There are 11,000+ MCP servers listed across registries, but most are either local-only, slow, or require complex setup.

I wanted to build MCP servers that are:

Globally fast — edge-deployed, <50ms response
Zero setup — no API key, no install, just add a URL
Actually useful — solving real developer problems

Here's what I built and what I learned.

The 9 Servers

Each server is a Cloudflare Worker with a specific focus:

JSON Toolkit — format, validate, diff, query (JSONPath), transform, auto-generate schema. Every API developer needs this daily.

Regex Engine — test patterns, explain regex in plain English, build regex from natural language descriptions. No more regex101 tab switching.

Color Palette — generate harmonious palettes, check WCAG contrast ratios, convert between hex/rgb/hsl, create CSS gradients, look up Tailwind colors.

Timestamp Converter — convert between formats, timezone handling, parse cron expressions (shows next 5 runs), calculate time differences.

Prompt Enhancer — optimize LLM prompts, analyze clarity scores, convert between prompt formats, generate system prompts from descriptions.

Plus 4 more: Market Intel, Fortune/Tarot, Content Publisher, and AI Tool Comparison.

Architecture

Each Worker follows the same pattern:

HTTP transport (MCP over HTTP, not stdio)
Cloudflare KV for rate limiting per IP
Free tier (3-50 calls/day depending on compute cost)
Pro tier ($9/month, 1000/day via shared API key)

Install

One-line for Claude Desktop or Cursor:

npx -y @smithery/cli@latest install @openclaw-ai/json-toolkit-mcp --client claude

Or direct MCP config:

{
  "mcpServers": {
    "json-toolkit": {
      "url": "https://json-toolkit-mcp.yagami8095.workers.dev/mcp"
    }
  }
}

All 9 servers are live on Smithery and GitHub.

What I Learned

HTTP transport wins — stdio requires local process management. HTTP just works everywhere.
Cloudflare Workers are perfect for MCP — sub-50ms cold starts, global edge, built-in KV.
Free tier is essential — nobody will pay before trying. Rate limits are the natural upgrade trigger.
Smithery is the app store for MCP — easiest discovery path for Claude/Cursor users.