Working with HyperCore

This guide provides a comprehensive overview for developers on how to use the Across Swap API to bridge USDT-SPOT to/from HyperCore, integrated via HyperEVM. We will be focusing on how using the Swap API abstracts away all complexities to ensure a smooth developer and user experience.

Important Parameters for the Swap API Call

To bridge USDT-SPOT to/from HyperCore, you make a standard call to the /swap/approval endpoint. The key is to specify HyperCore destinationChainId: 1337 and USDT-SPOT outputToken: 0x200000000000000000000000000000000000010C in the destination parameters.

While using the GET /swap/chains endpoint, you will see HyperCore listed with chainId: 1337 .

Next up, we will look at 2 major use cases of the /swap/approval call while working with HyperCore.

You must initialize your depositor account on HyperCore by transferring at least 1 USDT0 to your account before conducting a crosschain swap with this account as the recipient. Check your balance at hyperliquid.xyz/portfolio

If the depositor account is not initialized on HyperCore, the Swap API will throw the following error:

{
  "type": "AcrossApiError",
  "code": "INVALID_PARAM",
  "status": 400,
  "message": "HyperEVM -\u003E HyperCore: Depositor is not initialized on HyperCore",
  "id": "jtmct-1760080200505-ce1bd0d88e2f"
}

From any EVM chain (like Arbitrum) to HyperCore

https://app.across.to/api/swap/approval?
tradeType=exactInput&
inputToken=0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9&
originChainId=42161& // arbitrum
outputToken=0x200000000000000000000000000000000000010C& // USDT-SPOT
destinationChainId=1337& // HyperCore
depositor=0x9A8f92a830A5cB89a3816e3D267CB7791c16b04D&
amount=1000000

Output

{
  "crossSwapType": "bridgeableToBridgeableIndirect",
  "amountType": "exactInput",
  "checks": {
    "allowance": {
      "token": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
      "spender": "0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A",
      "actual": "115792089237316195423570985008687907853269984665640564039457584007807744139935",
      "expected": "1000000"
    },
    "balance": {
      "token": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
      "actual": "12607096",
      "expected": "1000000"
    }
  },
  "steps": {
    "bridge": {
      "inputAmount": "1000000",
      "outputAmount": "998773",
      "tokenIn": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
        "name": "Tether USD",
        "chainId": 42161
      },
      "tokenOut": {
        "symbol": "USDT",
        "name": "Tether USD",
        "decimals": 6,
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "chainId": 999,
        "coingeckoId": "tether"
      },
      "fees": {
        "totalRelay": {
          "total": "1227",
          "pct": "1227000000000000",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
            "name": "Tether USD",
            "chainId": 42161
          }
        },
        "relayerCapital": {
          "total": "100",
          "pct": "100000000000000",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
            "name": "Tether USD",
            "chainId": 42161
          }
        },
        "relayerGas": {
          "total": "1127",
          "pct": "1127000000000000",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
            "name": "Tether USD",
            "chainId": 42161
          }
        },
        "lp": {
          "total": "0",
          "pct": "0",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
            "name": "Tether USD",
            "chainId": 42161
          }
        }
      }
    }
  },
  "inputToken": {
    "decimals": 6,
    "symbol": "USDT",
    "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
    "name": "Tether USD",
    "chainId": 42161
  },
  "outputToken": {
    "symbol": "USDT-SPOT",
    "name": "Tether USD",
    "decimals": 8,
    "address": "0x200000000000000000000000000000000000010C",
    "chainId": 1337,
    "coingeckoId": "tether"
  },
  "refundToken": {
    "decimals": 6,
    "symbol": "USDT",
    "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
    "name": "Tether USD",
    "chainId": 42161
  },
  "fees": {
    "total": {
      "amount": "1226",
      "amountUsd": "0.001226999999999978",
      "pct": "1226999999999978",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
        "name": "Tether USD",
        "chainId": 42161
      }
    },
    "originGas": {
      "amount": "3176078275684",
      "amountUsd": "0.013793803233643881",
      "token": {
        "chainId": 42161,
        "address": "0x0000000000000000000000000000000000000000",
        "decimals": 18,
        "symbol": "ETH"
      }
    },
    "destinationGas": {
      "amount": "25607816405362",
      "amountUsd": "0.001127",
      "pct": "1127000000000000",
      "token": {
        "chainId": 999,
        "address": "0x0000000000000000000000000000000000000000",
        "decimals": 18,
        "symbol": "HYPE"
      }
    },
    "relayerCapital": {
      "amount": "100",
      "amountUsd": "0.0001",
      "pct": "100000000000000",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
        "name": "Tether USD",
        "chainId": 42161
      }
    },
    "lpFee": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
        "name": "Tether USD",
        "chainId": 42161
      }
    },
    "relayerTotal": {
      "amount": "1227",
      "amountUsd": "0.001227",
      "pct": "1227000000000000",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9",
        "name": "Tether USD",
        "chainId": 42161
      }
    },
    "app": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "symbol": "USDT-SPOT",
        "name": "Tether USD",
        "decimals": 8,
        "address": "0x200000000000000000000000000000000000010C",
        "chainId": 1337,
        "coingeckoId": "tether"
      }
    }
  },
  "inputAmount": "1000000",
  "maxInputAmount": "1000000",
  "expectedOutputAmount": "99877300",
  "minOutputAmount": "99877300",
  "expectedFillTime": 2,
  "swapTx": {
    "simulationSuccess": true,
    "chainId": 42161,
    "to": "0xe35e9842fceaCA96570B734083f4a58e8F7C5f2A",
    "data": "0xad5...0073c0de",
    "gas": "100484",
    "maxFeePerGas": "31607801",
    "maxPriorityFeePerGas": "1"
  },
  "id": "kwnvz-1760078642040-c3005198326d"
}

This is a standard crosschain swap that settles on HyperEVM before being credited to HyperCore:

1. Deposit on Origin: The user's transaction calls the SpokePool on the origin chain, emitting a FundsDeposited event.

2. Fill on HyperEVM: An Across relayer fills the deposit, which emits a FilledRelay event.

3. Automatic Deposit to HyperCore: The Across API automatically appends a destination action to the relay. This action calls a specialized function on HyperEVM which, in turn, credits the user's USDT-SPOT balance on HyperCore. You do not need to specify this action in your API call.

---

From HyperEVM to HyperCore

https://app.across.to/api/swap/approval?
tradeType=exactInput&
inputToken=0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb&
originChainId=999& // HyperEVM
outputToken=0x200000000000000000000000000000000000010C& // USDT-SPOT
destinationChainId=1337& // HyperCore
depositor=0x9A8f92a830A5cB89a3816e3D267CB7791c16b04D&
amount=1000000

Output

{
  "crossSwapType": "bridgeableToBridgeable",
  "amountType": "exactInput",
  "checks": {
    "allowance": {
      "token": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
      "spender": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
      "actual": "1000000",
      "expected": "1000000"
    },
    "balance": {
      "token": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
      "actual": "8705262",
      "expected": "1000000"
    }
  },
  "steps": {
    "bridge": {
      "inputAmount": "1000000",
      "outputAmount": "100000000",
      "tokenIn": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "name": "Tether USD",
        "chainId": 999
      },
      "tokenOut": {
        "decimals": 8,
        "symbol": "USDT-SPOT",
        "address": "0x200000000000000000000000000000000000010C",
        "name": "Tether USD",
        "chainId": 1337
      },
      "fees": {
        "totalRelay": {
          "pct": "0",
          "total": "0",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
            "name": "Tether USD",
            "chainId": 999
          }
        },
        "relayerCapital": {
          "pct": "0",
          "total": "0",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
            "name": "Tether USD",
            "chainId": 999
          }
        },
        "relayerGas": {
          "pct": "0",
          "total": "0",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
            "name": "Tether USD",
            "chainId": 999
          }
        },
        "lp": {
          "pct": "0",
          "total": "0",
          "token": {
            "decimals": 6,
            "symbol": "USDT",
            "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
            "name": "Tether USD",
            "chainId": 999
          }
        }
      }
    }
  },
  "inputToken": {
    "decimals": 6,
    "symbol": "USDT",
    "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
    "name": "Tether USD",
    "chainId": 999
  },
  "outputToken": {
    "decimals": 8,
    "symbol": "USDT-SPOT",
    "address": "0x200000000000000000000000000000000000010C",
    "name": "Tether USD",
    "chainId": 1337
  },
  "refundToken": {
    "decimals": 6,
    "symbol": "USDT",
    "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
    "name": "Tether USD",
    "chainId": 999
  },
  "fees": {
    "total": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "name": "Tether USD",
        "chainId": 999
      }
    },
    "originGas": {
      "amount": "6604950000000",
      "amountUsd": "0.000291014097",
      "token": {
        "chainId": 999,
        "address": "0x0000000000000000000000000000000000000000",
        "decimals": 18,
        "symbol": "HYPE"
      }
    },
    "destinationGas": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "chainId": 1337,
        "address": "0x0000000000000000000000000000000000000000",
        "decimals": 18,
        "symbol": "HYPE"
      }
    },
    "relayerCapital": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "name": "Tether USD",
        "chainId": 999
      }
    },
    "lpFee": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "name": "Tether USD",
        "chainId": 999
      }
    },
    "relayerTotal": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 6,
        "symbol": "USDT",
        "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
        "name": "Tether USD",
        "chainId": 999
      }
    },
    "app": {
      "amount": "0",
      "amountUsd": "0.0",
      "pct": "0",
      "token": {
        "decimals": 8,
        "symbol": "USDT-SPOT",
        "address": "0x200000000000000000000000000000000000010C",
        "name": "Tether USD",
        "chainId": 1337
      }
    }
  },
  "inputAmount": "1000000",
  "maxInputAmount": "1000000",
  "expectedOutputAmount": "100000000",
  "minOutputAmount": "100000000",
  "expectedFillTime": 0,
  "swapTx": {
    "simulationSuccess": true,
    "chainId": 999,
    "to": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb",
    "data": "0xa9059c...0000f424073c0de",
    "value": "0",
    "gas": "44033",
    "maxFeePerGas": "150000000",
    "maxPriorityFeePerGas": "0"
  },
  "id": "sx2pv-1760078744204-3531c066a03e"
}

This flow is a direct deposit rather than a traditional crosschain swap:

1. Direct Deposit: The user deposits on HyperEVM with an attached transfer function for HyperCore. You do not need to specify this action in your API call.

2. Credit on HyperCore: This function immediately executes the logic to credit the user's USDT-SPOT balance on HyperCore. This is a single, synchronous transaction with no FundsDeposited or FilledRelay events.

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Read the API Reference and in case you face any errors or need support, please feel free to reach out to us.