{"version":"x402/2","x402Version":2,"provider":{"name":"Rewards Fuel","description":"RFWIN Winner Picker — verifiable random draws with cryptographic proofs. Pay per draw with USDC. Built on drand quicknet randomness and commit-reveal protocols.","url":"https://app.rewardsfuel.com","docs":"https://rfwin.uk"},"treasury":"0x0000000000000000000000000000000000000001","chain":"eip155:84532","asset":"0x036CbD53842c5426634e7929541eC2318f3dCF7e","currency":"USDC","facilitator":"https://x402.org/facilitator","endpoints":[{"path":"/api/mcp/x402","method":"POST","type":"mcp","transport":"streamable-http","description":"MCP endpoint for draw_winners tool — verifiable random winner selection with cryptographic proofs","pricing":[{"product":"per_draw_dynamic","amount_usdc":0.08,"description":"Base price $0.08 + $0.0005 per entry after 50, capped at $2.00 (~3890 entries max)","formula":"price_usd = 0.08 + 0.0005 * max(0, entry_count - 50)","cap":2}],"tools":[{"name":"draw_winners","description":"Perform a verifiable random draw of winners from contestants and prizes. Each draw is recorded on rfwin.uk with cryptographic proof.","inputSchema":{"type":"object","properties":{"title":{"type":"string","description":"Optional title for the draw"},"contestants":{"type":"array","items":{"type":"string"},"description":"List of contestants (names, emails, or usernames)"},"prizes":{"type":"array","items":{"type":"object","properties":{"name":{"type":"string","description":"Name of the prize"},"quantity":{"type":"integer","description":"Number of winners for this prize (default: 1)"}},"required":["name"]},"description":"List of prizes and quantities to draw for"},"algorithm":{"type":"string","enum":["random","weighted"],"description":"Drawing algorithm: random (equal weight) or weighted. Default random."},"uniqueWinners":{"type":"boolean","description":"If true, a contestant can win at most one prize. Default true."}},"required":["contestants","prizes"]},"outputSchema":{"type":"object","properties":{"drawId":{"type":"string","description":"Unique draw identifier"},"verificationUrl":{"type":"string","description":"URL to view cryptographic proof on rfwin.uk"},"winners":{"type":"array","items":{"type":"object"},"description":"Selected winners with prize assignments"},"pricing":{"type":"object","properties":{"priceUsd":{"type":"number","description":"Actual price charged for this draw"},"entryCount":{"type":"integer","description":"Number of contestants"},"breakdown":{"type":"object","description":"Pricing calculation details"}}}}},"example":{"title":"Monthly Giveaway Draw","contestants":["alice@example.com","bob@example.com","charlie@example.com"],"prizes":[{"name":"First Prize","quantity":1},{"name":"Runner Up","quantity":2}],"algorithm":"random","uniqueWinners":true}}],"returns":{"format":"json-rpc-2.0","description":"MCP JSON-RPC response with draw results and verification URL"}}]}