> ## Documentation Index
> Fetch the complete documentation index at: https://docs.groundtech.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported Chains

> Portfolio wallet deposit and withdrawal coverage.

Portfolio wallet chain support depends on both the stablecoin and the operation.

## Production

| Stablecoin | Deposits                                  | Withdrawals                               | Yield strategy                               |
| ---------- | ----------------------------------------- | ----------------------------------------- | -------------------------------------------- |
| USDC       | Arbitrum, Base, Ethereum, Polygon, Solana | Arbitrum, Base, Ethereum, Polygon, Solana | Sources returned with `depositToken: "usdc"` |
| USDT       | Ethereum                                  | Ethereum                                  | USDT cash                                    |

USDT does not bridge between chains and Ground does not convert between USDT and USDC. A production USDT withdrawal must use `token: "usdt"` and `destinationChain: "ethereum"`.

Production USDT deposits and withdrawals are supported on Ethereum only. USDT is not bridged to Arbitrum, Base, Polygon, Solana, or Tron, and Ground does not convert between USDT and USDC.

If a chain is unsupported for the action you’re attempting, the API returns a 400 error with details.

## Sandbox

Sandbox uses explicit testnet chain keys in both responses and request parameters. For example, use `ethereum_sepolia` instead of `ethereum`.

| Stablecoin | Sandbox deposits and withdrawals                           |
| ---------- | ---------------------------------------------------------- |
| USDC       | `ethereum_sepolia`, `solana_devnet`                        |
| USDT       | `ethereum_sepolia` only, using Ground's mock USDT contract |

Sandbox USDT is an integration-test asset. It is not public Sepolia USDT and does not imply support for USDT outside Ethereum mainnet in production.

Sandbox USDT on `ethereum_sepolia` uses Ground-owned mock contracts. It is a product test surface, not general public Sepolia USDT support.

Production uses canonical chain names (`arbitrum`, `base`, `ethereum`, `polygon`, `solana`).

<Info>
  NOTE: USDC deposits and withdrawals on some chains may require additional time to bridge via [CCTP](https://www.circle.com/cross-chain-transfer-protocol). Withdrawal previews currently estimate this CCTP leg at about 20 minutes (`PT20M`), while live settlement can vary by chain and attestation conditions.
</Info>