approveBuilderFee

Approve a maximum fee rate that a builder (DeFi application) can charge on trades executed on your behalf. Builder codes enable third-party applications to earn fees for order routing.

Sample Data#

{
  "signature": {
    "r": "0x819ad144d5c0c3d55a176f1b61ee61f2ad290f1b4cc2afb3944c2f70235a507d",
    "s": "0x2fea989745633804f70c5528c9258a89b3789bd99c6a03c6a1bd884cf5dc1b6b",
    "v": 28
  },
  "action": {
    "type": "approveBuilderFee",
    "signatureChainId": "0x66eee",
    "hyperliquidChain": "Mainnet",
    "maxFeeRate": "0.01%",
    "builder": "0x6530512a6c89c7cfcebc3ba7fcd9ada5f30827a6",
    "nonce": 1768146914155
  },
  "nonce": 1768146914155
}

View this transaction on Hypurrscan →

Field Reference#

Action Fields#

Field	Type	Description
`type`	string	Always `"approveBuilderFee"`
`maxFeeRate`	string	Maximum fee rate the builder can charge (e.g., `"0.001"` = 0.1%)
`builder`	string	Ethereum address of the builder
`nonce`	number	Timestamp-based nonce for replay protection

Fee Limits#

Hyperliquid enforces maximum builder fees:

Market Type	Maximum Builder Fee
Perpetuals	0.1% (10 basis points)
Spot	1% (100 basis points)

Builder codes do not apply to the buying side of spot trades.

How Builder Fees Work#

User approves a max fee rate for a builder address
Builder submits orders with a fee parameter: {"b": address, "f": fee_bps}
Fee is deducted from the user's trade and credited to the builder
Builders claim fees through the referral reward system

Use Cases#

DeFi Integration Tracking#

Monitor which builders users are authorizing:

def process_approveBuilderFee_action(action):
    builder = action.get('builder')
    max_fee = float(action.get('maxFeeRate', 0))

    print(f"Builder approved: {builder} with max fee {max_fee * 100}%")

Fee Analytics#

Track builder fee approvals to understand:

Popular trading interfaces
Average fee tolerance
Builder market share

Competition Analysis#

Monitor which builders are gaining traction in the Hyperliquid ecosystem.

Requirements#

Builder must maintain at least 100 USDC in perps account value
Approval must be signed by the user's main wallet (not an agent)
Users can revoke permissions at any time

approveAgent - Authorize API wallets
order - Orders can include builder fee parameters