Proof of concept · Casino × x402

A casino built for AI agents.

Pay per play with x402 (USDC on Base). Verify every roll with commit-reveal fairness. Withdraw on-chain.

A proof of concept exploring what autonomous agents can do with the x402 protocol. See Terms.

Read the docs View games ↓ skill.md for agents

Base mainnetUSDC settlementProvably fair

Four games, three stakes each

Stake tiers are selected with ?stake=micro|standard|whale. The tier maps to a different x402 price on the same route.

Game	Stake tiers	Payout	Endpoint
Coin Flip Heads or tails.	micro: $0.10standard: $1.00whale: $10.00	1.96×	/api/v1/games/coinflip
Dice (over/under 1-100) Pick a threshold 2-99 and a direction.	micro: $0.10standard: $1.00whale: $10.00	1.00× – 99×	/api/v1/games/dice
European Roulette Single-zero, 0-36.	micro: $0.10standard: $1.00whale: $10.00	2× / 3× / 36×	/api/v1/games/roulette
3-Reel Slots 6 symbols, 3 reels.	micro: $0.10standard: $1.00whale: $10.00	2× – 120×	/api/v1/games/slots

Provably fair

Every bet is a deterministic HMAC of a committed server seed, the agent's client seed, and a nonce. After rotation, the seed is revealed — agents can verify any past bet.

Commit

Fetch sha256(server_seed) from /api/v1/seed/commit before playing.

Play

Include your client_seed and nonce in the bet. Outcome = HMAC-SHA256(server_seed, client_seed:nonce).

Verify

After seed rotation, /api/v1/seed/reveal returns the raw seed. Replay HMAC yourself.

Verification snippet

import crypto from "node:crypto";

// 1. after seed rotation, fetch the revealed seed
const { seed } = await fetch("/api/v1/seed/reveal?seed_id=...").then(r => r.json());

// 2. replay the HMAC
const msg = `${bet.client_seed}:${bet.nonce}`;
const hex = crypto.createHmac("sha256", Buffer.from(seed, "hex")).update(msg).digest("hex");

// 3. compare against bet.outcome — deterministic, tamper-evident.

Agent discovery

Discoverable via standard agent protocols. No human login required.

↓ Download skill.md

skill

Agent skill

Drop-in skill.md for any LLM agent

ucp

UCP profile

Universal Capability Protocol

acp

ACP manifest

Agent Commerce Protocol

x402

x402 paywall

HTTP 402 Payment Required

Quick start for agents

curl -O https://x402casinos.com/skill.md
# or, machine-readable:
curl -s https://x402casinos.com/.well-known/skill.json | jq

FAQ

Can humans play?+

There is no human UI for betting. All play happens programmatically via the HTTP API. Humans can view stats on the backoffice once authenticated.

Are outcomes manipulable?+

No. Each bet uses a server seed whose hash is published before play. The seed is later revealed so agents can replay the HMAC and verify.

What happens if settlement fails?+

The bet is flagged pending_settlement. A reconciler voids it after 10 minutes. No balance is credited.

What about regulation?+

See README.md — a gaming licence is required before any public mainnet launch.

Ready to play?

Grab the docs, sign an EIP-3009 authorization, and POST to any game endpoint.

Open the docs