# Doubloon

- **Event:** [Meta Global AI Developer Hackathon](https://cerebralvalley.ai/e/meta-ai-developer-hackathon)
- **When:** Oct 26, 12:00 PM – Nov 4, 9:00 PM (EST)
- **Where:** Online
- **Team:** [Nathanael Muller](https://cerebralvalley.ai/u/nmuller17), [Maximilien Rambaud](https://cerebralvalley.ai/u/Maxramb), [Cosme de Ranieri](https://cerebralvalley.ai/u/cosmedr)
- **GitHub:** https://github.com/nmuller17/Meta-Globlal-AI-Developer-Hackathon
- **Demo video:** https://www.youtube.com/watch?v=svdWuwi0hfs
- **Gallery:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/484

Doubloon is the payment layer for the agentic web: pay per fact, not per report. Any website can sell any piece of its content to any AI agent, in one payment. Meta's Muse Spark runs every language task; code decides every price, permission and payment.

THE PROBLEM WE KNOW FIRSTHAND
Before MIT, we worked in strategy consulting and M&A / private equity (BCG). We often needed one number (a market share, a growth rate, a competitor figure) the same day, and the only way to get it was a €3,000 report or a yearly subscription. That research is now done more and more by AI agents, and agents cannot pay for a single fact: no credit card, no checkout page, no account.
We saw the other side with one of our own websites: traffic and ad revenue kept falling as people asked AI assistants instead. The content was still read, by machines, but nobody paid for it.
Both problems miss the same piece: a way for any website to sell any piece of information to any AI agent, in one payment.

WHAT IT DOES
- For publishers, about 60 seconds and no code: paste your URL; Doubloon crawls it (respecting robots.txt) and splits HTML pages and PDF reports into sections. Muse Spark writes the catalog agents browse (topic, region, period, data type, never a figure). Mark each section Sell, Free or Private. Write prices in plain words ("$0.10 for one figure, $2 for a full section"); Muse Spark turns them into a price table you confirm. Connect your wallet and go live: USDC goes straight to your wallet, with a revenue dashboard and a full audit trail.
- For buyer agents, a sale in six steps: discover the publisher's signed manifest, prove identity with a wallet signature (KYA, Know Your Agent, with OFAC sanctions screening), negotiate with the publisher's Muse Spark sales agent, decide (Muse Spark weighs the offer against the mission, code enforces budget and caps, and above 1 USDC the human owner approves), pay through x402 (HTTP 402 Payment Required) in USDC on Base, and receive the data, watermarked, with a signed license receipt.
- In our demo, both sides are Muse Spark agents negotiating live with each other. Through our MCP connector, anyone's own AI assistant can be the buyer too.

MODEL PROPOSITION and CODE-BASED VALIDATION
Every Muse Spark call returns strict JSON-schema structured output, checked field by field. The sales agent never sees paid content. Exact price and tier, leak filter, prompt-injection handling, budgets and caps, replay protection and settlement before delivery are all deterministic code. If the model fails, Doubloon refuses safely so that it never gives data away.

BUILT TO HOLD UP IN PRODUCTION
- Real payments, not a mock-up: the payment pipeline has settled 64 payments on-chain, 2 of them on Base mainnet with real USDC, all public on BaseScan. Going from testnet to mainnet was configuration only.
- 173 automated tests (including the real SDK against a simulated Meta Model API) plus 5 end-to-end on-chain test scripts.
- Security and compliance built in: OFAC screening, signed manifests, SHA-256 audit chain, per-buyer watermarks, crash recovery from the chain, 24h re-download, GDPR data retention.
- Stack: Muse Spark on the Meta Model API, FastAPI gateway, SQLite, x402 v2 + EIP-3009, Next.js / React / wagmi web app, MCP server.

BUSINESS MODEL AND NEXT STEPS
Publishers keep 100% of their price; Doubloon charges a flat $0.01 per transaction. Next: serve the 402 from the publisher's own domain (Cloudflare / WordPress / Next.js plugin), have Muse Spark split each report into individual facts priced one by one, and add signed bot authentication (Web Bot Auth) next to wallet KYA.

## More from Meta Global AI Developer Hackathon

- [Quantum Pixels](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/481)
- [KISKY TEAM](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/482)
- [Amr Elhabbal - Neura](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/483)
- [MkDev](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/485)
- [GROWHAND](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/486)
- [Clarity Room](https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/487)

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Markdown version of https://cerebralvalley.ai/e/meta-ai-developer-hackathon/hackathon/gallery/484. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt