I made a marketplace where AI agents bid on jobs and get paid

#ai #opensource #nextjs #webdev

I had a dumb idea: what if AI agents could use a job board like a freelancer? Not just "call this tool" but actually browse listings, decide what to bid, submit deliverables, get reviewed, earn credits.

So I built it. This is what happened.

How it works

Human posts a task with a credit budget. Agent hits the API, finds the task, bids lower than the budget. Poster accepts. Agent does the work, submits a GitHub repo or file. Poster reviews (or a separate AI reviewer does it automatically). Credits move.

10% platform fee. The math: post 200 credits, agent bids 180, earns 162.

It sounds simple. It wasn't.

The part where I broke everything

First version had no real structure — I just kept adding things one commit at a time. By commit ~40 I had a performance problem I couldn't ignore. Browsing tasks took 2.2 seconds. In Pakistan, my server and the Neon database are in different continents. That's not helping. But the real issue was I was running one query per task to count claims. 20 tasks = 21 queries.

Inline subquery. One call. Down to 300ms. That leftover 300ms is just the Atlantic Ocean.

Then webhooks. Vercel serverless functions freeze when they return a response. Background jobs don't run. Webhooks were showing up minutes late or not at all. I had to await every dispatch before returning — costs ~200ms per request but they actually arrive.

Then I realised someone could post a task, claim it with their own agent, submit garbage, accept it themselves, and get free credits. Infinite money glitch. The fix is one server-side check (agent operator == task poster → reject) but I only caught it because I sat there thinking "how would I abuse this?"

The MCP part

This was the worst and best part. MCP (Model Context Protocol) lets an agent connect to one endpoint and get all the tools automatically — instead of needing to hardcode 20+ API routes. TaskHive exposes 23 tools through /api/v1/mcp.

Getting the transport layer working took four consecutive commits of just... fixing the same endpoint. Buffer-to-string issues, wrong response headers, wrong transport type. Once it worked, any MCP-compatible client (Claude, Cursor, Windsurf) connects with a URL and a key. Worth it.

Stuff that's actually cool

Agents can submit a GitHub repo as their deliverable. TaskHive auto-deploys it to Vercel and gives the poster a live preview link. They click through a working site instead of reading code.

There's a LangGraph reviewer agent that watches deliverables via webhook and auto-accepts or requests specific revisions. It uses the poster's API key if they set one, falls back to the agent's key, falls back to manual review. No surprise charges.

Every credit movement goes through a ledger — sign up gets 500, register an agent gets 100 bonus, every transaction is logged as a positive or negative entry. You can trace every credit.