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Yellow Network Integration

Overview​

JACK integrates with Yellow Network to provide instant off-chain settlement through ERC-7824 state channels. The integration uses the ClearNode sandbox on Sepolia, with a singleton YellowProvider from @jack-kernel/sdk managing the channel lifecycle inside the dashboard.

Integration Status​

✅ Live on Sepolia Testnet — State channel settlement is available as a demo settlement method in the dashboard.

Contracts (Sepolia)​

ContractAddressEtherscan
Custody0x019B65A265EB3363822f2752141b3dF16131b262View
Adjudicator0x7c7ccbc98469190849BCC6c926307794fDfB11F2View

ClearNode Sandbox​

EndpointURL
WebSocketwss://clearnet-sandbox.yellow.com/ws
Faucethttps://clearnet-sandbox.yellow.com/faucet/requestTokens

Architecture​

┌─────────────────────────────────────────────────────────────────┐
│  Dashboard                                                       │
│  ┌─────────────────────┐  ┌───────────────────────────────┐    │
│  │  SettlementSelector │  │  ChannelStatusPanel           │    │
│  │  (settlement method │  │  - Channel ID / status        │    │
│  │   picker)           │  │  - State version / hash       │    │
│  └─────────┬───────────┘  │  - Adjudicator link           │    │
│            │              │  - Settlement tx (Etherscan)   │    │
│            ▼              │  - ERC-7824 metadata           │    │
│  ┌─────────────────────┐  └───────────────────────────────┘    │
│  │  lib/yellow.ts      │                                        │
│  │  (singleton mgr)    │                                        │
│  └─────────┬───────────┘                                        │
└────────────┼────────────────────────────────────────────────────┘
             │
             ▼
┌─────────────────────────────────────────────────────────────────┐
│  @jack-kernel/sdk · YellowProvider                              │
│  ┌──────────────────────┐  ┌──────────────────────┐            │
│  │  State Channel Mgmt  │  │  Off-Chain Transfers │            │
│  │  - Open / close      │  │  - Instant payments  │            │
│  │  - Challenge period  │  │  - No gas fees       │            │
│  └──────────────────────┘  └──────────────────────┘            │
│              │                        │                          │
│              └────────────┬───────────┘                          │
│                           ▼                                      │
│              ┌──────────────────────┐                           │
│              │  On-Chain Settlement │                           │
│              │  Custody + Adjudicator                           │
│              │  (Sepolia)          │                            │
│              └──────────────────────┘                           │
└─────────────────────────────────────────────────────────────────┘

Dashboard Integration​

Singleton Provider (lib/yellow.ts)​

The dashboard manages a singleton YellowProvider instance:

import { YellowProvider } from "@jack-kernel/sdk";
import type { YellowConfig, WalletClient } from "@jack-kernel/sdk";

// Sepolia addresses
const SEPOLIA_YELLOW_ADDRESSES = {
  custody: "0x019B65A265EB3363822f2752141b3dF16131b262",
  adjudicator: "0x7c7ccbc98469190849BCC6c926307794fDfB11F2",
};

const CLEARNODE_WS_URL = "wss://clearnet-sandbox.yellow.com/ws";

Four functions manage the provider lifecycle:

FunctionPurpose
createSepoliaYellowConfig()Returns a YellowConfig with Sepolia addresses, chainId 11155111, 3600 s challenge period, and ClearNode WebSocket URL
initYellowProvider(config, walletClient)Creates and stores a YellowProvider singleton
getYellowProvider()Returns the current singleton (or null)
resetYellowProvider()Clears the singleton

Settlement Selector​

When a user selects Yellow Network as the settlement method via the SettlementSelector component, the dashboard displays the custody and adjudicator contract addresses above the intent creation form.

Channel Status Panel​

The ChannelStatusPanel component renders real-time state channel information:

  • Channel ID — truncated with full value on hover
  • Status — colour-coded (active green, final blue, dispute red)
  • State Version and State Hash
  • Adjudicator — linked to Sepolia Etherscan
  • Challenge Period — in seconds
  • Settlement Tx — linked to Etherscan when available
  • ERC-7824 Metadata — proof count, nonce

Settlement API (/api/settlement)​

The GET /api/settlement endpoint returns Yellow Network configuration:

{
  "methods": {
    "yellow": {
      "status": "demo",
      "network": "sepolia",
      "chainId": 11155111,
      "contracts": {
        "custody": "0x019B65A265EB3363822f2752141b3dF16131b262",
        "adjudicator": "0x7c7ccbc98469190849BCC6c926307794fDfB11F2"
      },
      "clearNodeUrl": "wss://clearnet-sandbox.yellow.com/ws",
      "faucetUrl": "https://clearnet-sandbox.yellow.com/faucet/requestTokens"
    }
  }
}

The POST /api/settlement endpoint supports the yellow:faucet action, which proxies a token request to the ClearNode sandbox faucet:

curl -X POST /api/settlement \
  -H "Content-Type: application/json" \
  -d '{"action": "yellow:faucet", "userAddress": "0x..."}'

Usage with the SDK​

Initialize​

import { createSepoliaYellowConfig, initYellowProvider } from "@/lib/yellow";

const config = createSepoliaYellowConfig();
const provider = initYellowProvider(config, walletClient);

Open a Channel​

const channel = await provider.createChannel({
  counterparty: "0x...",
  asset: "0x...",
  initialAmount: parseEther("1.0"),
});

Off-Chain Transfers​

await provider.transfer({
  channelId: channel.id,
  amount: parseEther("0.1"),
  recipient: "0x...",
});

Close and Settle​

const tx = await provider.closeChannel({ channelId: channel.id });
console.log("Settlement:", `https://sepolia.etherscan.io/tx/${tx.hash}`);

Resources​

Integration Status: ✅ Live on Sepolia
Settlement Method ID: yellow
Network: Sepolia (chain ID 11155111)