HireMind: pay an agent, get a brief, keep the receipt

Open Track entry for SERV Hackathon 02. A seller agent on the OpenServ network writes research briefs for a fixed on-chain price. Buyers pay on Kite testnet, the app verifies the payment on-chain, the brief is delivered with a receipt that links back to the transaction.

Live loop: topic in, 0.01 KITE out, brief plus receipt back.

Demo video

Pro cut, 95.8s: voiceover with synced captions, original score, logo end-card. Payment evidence is a viewer-paid 0.01 KITE transaction (KiteScan, block 22043830, receipt success). Sample footage is labeled on the landing hero; the generation path is labeled on every receipt.

Architecture

• agent/: OpenServ seller agent (@openserv-labs/sdk + @openserv-labs/client). Single run-less capability research_brief. Registered via provision() with a webhook trigger (agent 4926, workflow HireMind Brief Machine).
• app/api/brief/route.ts: x402-style paywall. POST {topic} returns 402 with price and seller address. POST {topic, txHash} verifies the payment on Kite testnet (recipient, amount >= price so overpayment is accepted and recorded, receipt status, replay guard), tries the OpenServ webhook (60s), then falls back to direct generation and returns brief + receipt. A hash pays out exactly once; generation failure releases the claim so the same hash can be retried without paying twice. The two paths run sequentially, never as a race, so a late webhook can never overwrite a delivered brief.
• app/lib/brief.ts: direct generation fallback chain: AgentRouter, then any OpenAI-compatible provider (with token-budget escalation for reasoning models), then Pollinations free tier. All paths strip em/en dashes from model output per the DESIGN.md house rule.
• app/lib/markdown.tsx: tiny safe renderer for brief markdown. Builds React nodes directly, never raw HTML, so model output stays inert. Supports headings, lists, bold, and links (http and https only).
• app/page.tsx: marketing landing (hero with a sample receipt from a real overpaid delivery, proof line, how-it-works call and response column, showcase of real briefs, price, FAQ). See DESIGN.md for the design contract.
• app/brief/: the buy flow lives here. Topic field and price, payment with on-chain verification, brief renders as a document below, receipt as a stamped slip.
• app/privacy/, app/not-found.tsx, app/robots.ts, app/sitemap.ts, public/llms.txt: finish line checklist (privacy note, 404, robots, sitemap, llms.txt). Canonical tags on / and /brief, JSON-LD (WebSite plus SoftwareApplication) on the landing.

Setup

# web app
cp .env.example .env.local   # fill SELLER_ADDRESS (+ optional provider keys)
npm install
npm run dev                  # localhost:3000

# seller agent (optional: the direct fallback works without it, the receipt
# then records the fallback model instead of openserv-runtime)
cd agent
cp .env.example .env         # fill OPENSERV_USER_API_KEY + SELLER_ADDRESS
npm install
npm run dev

The agent prints its webhook URL on startup and writes agent/.openserv.json. The web app reads that file automatically; OPENSERV_WEBHOOK_URL overrides it.

Try it

1. Enter a topic (or tap an example), get the price: 0.01 KITE on chain 2368.
2. Send exactly 0.01 KITE on Kite testnet to the seller address.
3. Paste the transaction hash, get the brief plus a receipt with an explorer link.

Kite testnet: chain ID 2368, RPC https://rpc-testnet.gokite.ai, faucet https://faucet.gokite.ai, explorer https://testnet.kitescan.ai.

Truthful notes for judges

• Settlement is x402-style (402, pay, verify, deliver), not the full x402 facilitator flow. Paid hashes never expire: each hash pays out exactly once (reused hashes are refused), overpayment is accepted with the actual amount recorded, underpayment and wrong-recipient payments are refused without burning the hash. No payment is ever stranded by age.
• Showcase sample content stays inside what was actually generated: no invented statistics. The one showcase finding that carried an unsourced percentage was rewritten to a plain claim.
• SERV Reasoning is the primary path: the paid request goes to the hiremind-seller agent (HireMind Brief Machine workflow) via the OpenServ webhook, and the platform runtime generates the brief. The direct fallback (AgentRouter / OpenAI-compatible / Pollinations) runs only when the webhook is unreachable, and the receipt honestly labels which path ran. A fallback brief is never reported as SERV Reasoning. As of this writing no completed SERV run has been observed in the server logs (every webhook attempt so far ended in the body timeout, then fallback), so a genuine end-to-end SERV delivery is still the one manual test to run before claiming it.
• Payment verification is fully on-chain against Kite testnet (chain 2368): success receipt, correct seller recipient, amount >= price. Wrong address, underpayment, failed txs, unknown hashes and other-chain hashes are all refused with a reason. No payment is ever lost to a wrong address.
• Replay protection is an atomic in-process claim (concurrent redemptions of the same hash cannot both pass) backed by a persistent .data/redeemed.json ledger so restarts cannot re-open a hash. Single-file ledger is demo-grade durability, not a production multi-instance store. If generation fails after a verified payment, the claim is released so the buyer can retry with the same hash instead of paying twice.