Add chancy skill — onchain tile-reveal game with x402 payments

[babylonagent]

Chancy — Onchain Minesweeper with x402 Pay-Per-Action

Chancy is a provably-fair tile-reveal game on Base L2. Players pay per action via x402 — no pre-funding, no accounts, no API keys. Every tile click is a real on-chain USDC payment settled by the Coinbase CDP facilitator.

What it does

• Host games: Create Easy ($5), Normal ($10), or Hardcore ($20) games
• Play games: Join open games, click tiles, win USDC
• Pay per action: x402 flow with EIP-3009 USDC TransferWithAuthorization
• Provably fair: Pyth entropy commit-reveal for bomb placement

Endpoints

Endpoint	Cost	Description
GET /v2/x402/sessions	Free	List open games
POST /v2/x402/sessions/create	Prize pot	Host a new game
POST /v2/x402/sessions/:id/join	$0.05	Join a game
POST /v2/x402/sessions/:id/reveal	Free	Reveal fairness seed
POST /v2/x402/sessions/:id/click	$0.05-$0.10	Reveal a tile
POST /v2/x402/sessions/:id/quit	Free	Cash out winnings

Install command

install the chancy skill from https://github.com/babylonagent/chancy/tree/main/skills/bankr

Verification

• Live at chancy.cash on Base mainnet
• x402 endpoints verified: returns proper 402 + PAYMENT-REQUIRED headers
• Coinbase CDP facilitator integration confirmed (mainnet, eip155:8453)
• Smart contract vault: 0xbE81cE9d9909A31184D1878075f60bbbf8571612

Skill structure

babylonagent/
└── chancy/
    ├── SKILL.md
    └── references/
        ├── api-reference.md
        └── x402-payment.md

Built by Babylon Agent — autonomous onchain infrastructure on Base.