Multi-chain

One sub-wallet, one address, six chains. This page explains what that means in practice and where the asymmetries are.

Supported chains

Chain	ID	Native gas	Router
Ethereum	1	ETH	—
Optimism	10	ETH	—
BNB Chain	56	BNB	—
Polygon	137	POL	—
Base	8453	ETH	Yes
Arbitrum	42161	ETH	—

The authoritative list is dynamic — query GET /api/wallet/chains. Any chain returned there is supported; the documentation above may lag.

One address, many chains

EVM addresses are deterministic: the same private key produces the same address on every EVM chain. Your sub-wallet has one address that is valid everywhere. There is no per-chain provisioning step.

GET /api/wallet/address

{
  "addresses": {
    "evm": "0xA1b2C3d4e5F60718293A4B5c6d7E8f9012345678"
  },
  "sub_wallet_id": "sw_01HRZK..."
}

Funds on different chains are independent — sending USDC to your address on Ethereum does not make it appear on Base. Each balance is queried per chain.

has_router matters

The Router contract powers ShredPay's sponsored-gas flows. Sponsored operations only work on chains with has_router: true. Today that's Base only; more chains are in the pipeline.

Operation	Mainnet	Base	Arbitrum	Polygon	Optimism	BNB
send_transaction	yes	yes	yes	yes	yes	yes
simulate_transaction	yes	yes	yes	yes	yes	yes
execute_swap	—	yes	—	—	—	—
defi_deposit / defi_withdraw	—	yes	—	—	—	—
gas_swap	—	yes	—	—	—	—
Read tools (get_balance, …)	yes	yes	yes	yes	yes	yes

A sponsored call on a non-Router chain returns 400 ROUTER_NOT_AVAILABLE. Either move the operation to Base, or use send_transaction and pay gas yourself.

Per-chain key whitelisting

The allowed_chains array on an API key is checked first. If your bot only operates on Base, set allowed_chains: [8453] — every other chain returns 403 CHAIN_NOT_ALLOWED, no matter what the agent tries. This is the cheapest defense against a confused agent moving funds on the wrong chain.

Native gas per chain

If you intend to use send_transaction (the Agent-pays path), the sub-wallet needs the right native token on the right chain:

• Ethereum, Optimism, Base, Arbitrum → ETH

• BNB Chain → BNB

• Polygon → POL (formerly MATIC)

Use GET /api/gas/estimate?chain_id=… to see how much native gas a chain has. On Base you can self-fund through POST /api/gas/swap. On other chains you need to send native tokens to the address from outside.

Practical advice

• Default to Base. Lowest fees, full Router support, sponsored gas. Build there first.

• Use chain whitelists aggressively. They cost nothing and prevent footguns.

• Don't assume cross-chain liquidity. If your strategy needs USDC on both Mainnet and Arbitrum, plan the bridge yourself — Agent Wallet does not auto-bridge.

• Read GET /api/wallet/chains at startup. Cache for a session, but re-poll occasionally so new chains light up automatically.