Arc Testnet guide (Paylane)

Last updated: 2026-07-28
Network: Arc Testnet · Chain ID 5042002

This is the practical guide to run Paylane against real Arc testnet USDC — not the local demo simulator.

What “live on testnet” means

1. Prerequisites

1. Wallet with Arc Testnet USDC — Circle faucet
2. Foundry (forge) installed
3. Postgres running (./scripts/pg-start.sh or Docker)
4. Node 20+

Add Arc to your wallet:

USDC ERC-20 address: 0x3600000000000000000000000000000000000000

2. Deploy escrow (UUPS upgradeable)

cd workpay
export PRIVATE_KEY=0xYOUR_FUNDED_KEY
./scripts/deploy-arc-testnet.sh

This deploys PaylaneEscrowUpgradeable behind an ERC1967 proxy and writes:

packages/contracts/deployments/arc-testnet.json

Copy the proxy address into apps/web/.env:

NEXT_PUBLIC_NETWORK=testnet
NEXT_PUBLIC_CHAIN_ID=5042002
NEXT_PUBLIC_ARC_RPC=https://rpc.testnet.arc.network
NEXT_PUBLIC_USDC_ADDRESS=0x3600000000000000000000000000000000000000
NEXT_PUBLIC_ESCROW_ADDRESS=0xYourProxyAddress
NEXT_PUBLIC_EXPLORER_URL=https://testnet.arcscan.app
DEMO_MODE=false

Restart npm run dev. Open Settings — you should see “LIVE (on-chain)” and the proxy address.

Upgrades later

Owner can deploy a new implementation and call upgradeToAndCall on the proxy. Job balances stay in the proxy storage — no migration of funds.

forge script script/DeployUpgradeable.s.sol --rpc-url $ARC_RPC --broadcast
# then upgrade via cast / owner wallet

3. Live freelance flow (Mode A)

1. Connect wallet on Arc Testnet → Sign in (SIWE)
2. Post a job with checklist → Publish
3. Approve USDC & fund escrow — wallet prompts for approve + createJob + fundJob
4. Assign worker → worker starts → delivers (marks on-chain if live)
5. Client Accept & release on-chain (or wait for auto-release / dispute)

Receipts show Arcscan links when txs are real.

4. Mode B (API / Agents)

Still uses the x402 challenge on /api/demo/paid-weather. In DEMO_MODE, payments are HMAC proofs. For production Gateway nanopayments, set Circle facilitator credentials (see seller guide) — escrow upgrade does not replace Mode B.

5. Mainnet later

NEXT_PUBLIC_NETWORK=mainnet
NEXT_PUBLIC_CHAIN_ID=<arc-mainnet-id>
NEXT_PUBLIC_ARC_RPC=<rpc>
NEXT_PUBLIC_USDC_ADDRESS=<usdc>
NEXT_PUBLIC_ESCROW_ADDRESS=<new-or-same-proxy-deploy>
NEXT_PUBLIC_EXPLORER_URL=<explorer>
DEMO_MODE=false

Redeploy (or reuse an upgradeable proxy carefully) with mainnet USDC. Checklist: /docs/mainnet-checklist.

6. Troubleshooting

Settings page: /settings