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

# CCTP-enabled HyperCore transfers

CCTP lets you transfer USDC from all supported CCTP domains to HyperCore using a
`CoreDepositWallet` contract deployed on HyperEVM. The `CoreDepositWallet`
handles depositing and withdrawing USDC between HyperEVM and HyperCore. This
topic explains how the HyperCore workflow works and covers HyperCore-specific
considerations.

<Note>
  **Note:** HyperCore balances reflect protocol-level credits, not Circle-issued
  USDC. Native USDC remains in the `CoreDepositWallet` contract on HyperEVM and
  withdrawals are required to [redeem native USDC from
  HyperEVM](/cctp/howtos/withdraw-usdc-from-hypercore-to-evm).
</Note>

## How it works

The HyperCore workflow from source chains that are not HyperEVM is a two-step
process: funds are transferred in the standard CCTP workflow to HyperEVM, then
forwarded to HyperCore by depositing them into the `CoreDepositWallet` contract.

The burn transaction uses one of two contracts depending on the source chain:

* `TokenMessengerV2` contract
* `CctpExtension` contract

The burn transaction includes a hook that calls the `CctpForwarder` contract on
HyperEVM to forward the USDC to the recipient address on HyperCore.

Here's how the HyperCore deposit workflow works:

1. Check the CCTP API for fees. Fast transfers from Arbitrum with a HyperCore
   destination have no fast transfer fee. Using Circle's Forwarder Service to
   forward to HyperCore is optional and has a dynamic destination chain gas fee.
2. Calculate the USDC amounts minus fees.
3. Approve the contract to spend the amount of USDC you want to burn. If you are
   interacting with the `TokenMessengerV2` contract, you can do this with a call
   to the `approve` function on the USDC contract. If you are interacting with
   the `CctpExtension` contract on Arbitrum, you sign a
   `ReceiveWithAuthorization` message.
4. Sign and broadcast a burn transaction. The type depends on the source domain:
   * **CctpExtension contract on Arbitrum**: Sign and broadcast a
     `batchDepositForBurnWithAuth` transaction. Set HyperEVM as the destination.
     Include hook data to call the `CctpForwarder` contract on HyperEVM.
   * **TokenMessengerV2 contract**: Sign and broadcast a `depositForBurn`
     transaction. Set HyperEVM as the destination. Include hook data to call the
     `CctpForwarder` contract on HyperEVM.

HyperCore deposits and withdrawals are supported to/from any CCTP-supported
blockchain. Forwarding for these transfers is optional and is supported for all
[Forwarder-supported blockchains](/cctp/concepts/supported-chains-and-domains#supported-blockchains)
except for withdrawals to Solana.

## Important considerations

Keep these things in mind when using CCTP with HyperCore.

### Testnet recipient address limitations

When you test USDC transfers to HyperCore on testnet, the recipient address has
limits:

* The recipient address must already exist on HyperCore mainnet.
* Addresses that already exist on mainnet can only receive up to \$1000 testnet
  USDC.
* Transfers to addresses without mainnet state fail silently.

To check if an address exists on mainnet, use Hyperliquid's info API:

```shell theme={null}
curl -X POST https://api.hyperliquid.xyz/info \
  -H "Content-Type: application/json" \
  -d '
{
    "type": "userRole",
    "user": "${USER_ADDRESS}"
}
'
```

### Account activation fee on HyperCore

New HyperCore accounts are subject to a one-time 1 USDC activation fee, managed
entirely by the Hyperliquid protocol. Circle's `CoreDepositWallet` contract does
not collect or enforce this fee.

When a new user first deposits USDC to HyperCore, the full deposit amount is
credited to their tradable balance. The 1 USDC activation fee is earmarked at
the account level and charged on the user's first outbound action, such as a
withdrawal or `SendAsset` transfer. Until that first outbound action, the
account is considered unactivated and cannot perform
[CoreWriter actions](https://hyperliquid.gitbook.io/hyperliquid-docs/for-developers/api/activation-gas-fee).

This means:

* There is no minimum deposit amount. Deposits of any size, including less than
  1 USDC, will succeed.
* The user's first outbound action (withdrawal, transfer, etc.) requires a
  balance of at least 1 USDC. If the balance is below 1 USDC at that time, the
  action will fail.
* After the activation fee is paid, subsequent outbound actions are not subject
  to it.

<Note>
  The activation fee is separate from CCTP forwarding fees. When calculating
  total costs for a new user's first withdrawal, account for both the 1 USDC
  activation fee (charged by Hyperliquid) and any applicable CCTP forwarding
  fee.
</Note>

### Best practices for new account deposits

When your integration deposits USDC to a new HyperCore account:

* Ensure the deposit is large enough that the recipient will have at least 1
  USDC available for their first outbound action.
* Inform end users that their first withdrawal or transfer from HyperCore
  includes a one-time 1 USDC activation fee deducted by the Hyperliquid
  protocol.
* If your integration creates accounts programmatically (for example, contract
  addresses), you can pre-activate the account by sending an activation
  transaction to the EVM contract address on HyperCore, as described in
  [Hyperliquid's documentation](https://hyperliquid.gitbook.io/hyperliquid-docs/for-developers/api/activation-gas-fee).