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Why I Built AiPayGen: 244 AI Tools for the Price of One API Call

March 15, 2026 · 5 min read

The problem nobody talks about

If you build anything with AI, you know the drill. You need an OpenAI key for text generation. A separate Anthropic key for Claude. Google for Gemini. An Apify account for web scraping. A geocoding service. A sentiment analysis tool. Each one has its own dashboard, its own billing, its own SDK.

And every single one charges you a monthly minimum whether you use it or not.

I was spending $60/month across four providers and using maybe 2% of my quota. For side projects and prototypes, this is absurd. For AI agents that need to call tools dynamically, it's even worse — you can't predict which tools they'll need, so you end up subscribing to everything "just in case."

What if you could pay per call?

That's the core idea behind AiPayGen. One API endpoint, 244 tools, 15 AI models from 7 providers. You pay only when you make a call. No monthly fees. No unused quotas expiring at the end of the month.

Direct API call
~$0.03
+ monthly subscription
Via AiPayGen
~$0.006
Pay only what you use

The cost savings come from model routing. Not every request needs GPT-4o. A simple summarization task works fine with a smaller model. AiPayGen automatically picks the best model for the job — and passes the savings to you.

244 tools, not 244 model proxies

This isn't another OpenRouter. AiPayGen doesn't just forward your prompt to a model. Each of the 244 tools is purpose-built:

You can chain these together in workflows. Research a topic, summarize the findings, translate to Spanish, and generate a social media post — all in one API call with a 15% discount on the chain.

How it works under the hood

The architecture is deliberately simple:

The whole thing started on a Raspberry Pi 5 in my apartment. An $80 board serving 292 agents and 4183 APIs. I migrated to Oracle Cloud when I needed better uptime, but the Pi could still handle the traffic.

Get started in 30 seconds

Option 1: Try it in the browser

The /try page lets you test any tool without signing up or installing anything. Just pick a tool, enter your input, and see the result.

Option 2: curl

# Free — no key needed
curl "https://api.aipaygen.com/data/weather?city=Tokyo"

# AI tool — uses free tier (10 calls/day)
curl -X POST "https://api.aipaygen.com/summarize" \
  -H "Content-Type: application/json" \
  -d '{"text": "Paste any long text here", "length": "short"}'

# With API key — unlimited calls
curl -X POST "https://api.aipaygen.com/research" \
  -H "x-api-key: apk_your_key" \
  -H "Content-Type: application/json" \
  -d '{"topic": "best practices for AI agent architectures"}'

Option 3: MCP (for Claude Code / Cursor / Cline)

pip install aipaygen-mcp
claude mcp add aipaygen -- aipaygen-mcp

That's it. All 244 tools are now available in your AI coding assistant.

Free tier: 10 calls per day, no API key needed, no credit card required.
Paid: Load credits from $1 via Stripe. AI calls ~$0.006, utilities ~$0.002, scraping ~$0.01.
Crypto: Pay per call in USDC via x402 on Base, Solana, or Stellar.

What's next

AiPayGen is live and serving requests today. The roadmap includes more tools, better model routing, and growing the seller marketplace where anyone can register their API and get paid per call.

If you build with AI — whether it's agents, automations, or just the occasional API call — I'd genuinely appreciate you trying it out and telling me what's missing.

Try Free — No Signup View Pricing Get API Key ($1)

Published March 15, 2026. AiPayGen is an independent project by a solo developer. Questions or feedback? Reach out via the API Playground or GitHub.