Oleksandr

Posted on Sep 29

How I built 26 MCP servers + 2 REST APIs in 2 days with $0 infrastructure

#api #webdev #ai #crypto

I'm a solo developer. Over the last 2 days, I shipped:

26 MCP servers on MCPize (validators, converters, formatters)
2 REST APIs on Cloudflare Workers (HS Codes Classifier, Document-to-JSON)
1 custom x402 gateway (Furlpay, self-hosted)

Total infrastructure cost: $0.

This post is about how I did it, what worked, and what didn't.

The problem: getting paid as a solo dev

Traditional payment processors don't work for everyone. Depending on where you are, Stripe, PayPal, and similar services may not be available or may have restrictions.

I needed a payment path that:

Works globally
Has no signup friction
Can charge per call, not per month
Works natively with AI agents

Crypto is the answer.

And in 2026, there's a new protocol that makes crypto-native payments work natively with AI agents: x402.

What is x402?

x402 is a protocol built on top of HTTP. The idea is simple:

AI agent calls your API endpoint
Endpoint returns HTTP 402 Payment Required with payment details
Agent pays $0.01 USDC (on Base)
Agent re-calls with payment proof
Endpoint returns the result

No signup. No API keys. No OAuth. No subscriptions.

Just: pay per call.

It's designed for the AI agent economy — where an agent needs to call 100 different APIs, and signing up for each one is impractical.

The stack

Here's what I used:

1. Cloudflare Workers

Why: Serverless, stateless, free tier of 100k requests/day.

Numbers:

Cold start: 7ms
Free tier: 100k requests/day
Setup: npm install -g wrangler + wrangler deploy

Deploy code example:

export default {
  async fetch(request, env) {
    const url = new URL(request.url);

    if (url.pathname === "/health") {
      return new Response("OK");
    }

    if (url.pathname === "/classify") {
      const pay = paywall({
        price: 0.01,
        payTo: env.PAY_TO,
        quoteSecret: env.QUOTE_SECRET,
        network: "base",
      });

      return pay(async (req) => {
        const { description } = await req.json();
        const hsCode = await classify(description);
        return Response.json({ hs_code: hsCode });
      })(request, env);
    }

    return new Response("Not Found", { status: 404 });
  },
};

2. Furlpay (x402 gateway)

Why: Self-hosted x402 gateway. No vendor lock-in. 100% of payments go to my wallet.

Setup:

npm install -g @furlpay/gateway
furlpay-gateway secret
wrangler deploy

3. MCPize (MCP server distribution)

Why: MCP (Model Context Protocol) is how AI agents discover tools. MCPize is the marketplace.

What I did: Wrapped my APIs as MCP servers, deployed to MCPize. Now ChatGPT/Claude agents can find them.

4. gpt-4o-mini (for AI endpoints)

Why: Cheap, reliable. $0.15/1M input tokens.

At $0.01/call, margin is healthy even with heavy use.

What worked

Cloudflare Workers + Fetch API — perfect for stateless x402 APIs
Furlpay — one middleware = paywall
MCPize — free distribution for MCP servers
gpt-4o-mini — cheap AI

What didn't work

Reddit — new accounts get auto-filtered without karma
mcpize dev on Windows — broken (port conflict with itself). Use npm run dev instead.
Express + Cloudflare Workers — incompatible. Use Fetch API.

Results (so far)

26 MCP servers live
2 REST APIs live
$0 spent on infrastructure
0 customers (just launched)
$0 revenue (just launched)

What's next

First paying customer
More AI endpoints (Document Intelligence family)
Building in public

Try it

HS Codes Classifier (MCP): https://mcpize.com/mcp/hs-codes-mcp
HS Codes Classifier (REST): https://hs-codes-classifier.boring-saas-infra.workers.dev
Document-to-JSON (REST): https://document-to-json.boring-saas-infra.workers.dev

All APIs use x402 — pay $0.01 USDC per call, no signup.

If you're a solo dev and payment processors don't work for you — I'd love to hear how you handle it. Reply or DM.

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