fix: convert builder_fee bps to chain units before sending to contract

- Add bps_to_chain_units() utility function to convert basis points to chain units
  (multiply by 100, aligning with FEE_PRECISION = 10000 in contract)
- Update place_order() and place_twap_order() to convert builder_fee/builder_fees
- Update approve_max_builder_fee() to accept int|float and convert to chain units
- Sync both async and sync versions of these methods
- Update ApproveBuilderFeeArgs type definition to accept int|float

This matches the TypeScript SDK implementation and fixes precision issues.

Author: WGB5445

src/decibel/_utils.py

@@ -35,6 +35,7 @@
     "round_to_valid_order_size",
     "amount_to_chain_units",
     "chain_units_to_amount",
+    "bps_to_chain_units",
     "extract_vault_address_from_create_tx",
     "generate_random_replay_protection_nonce",
 ]
@@ -385,6 +386,21 @@ def amount_to_chain_units(amount: float, decimals: int = 6) -> int:
     return round(amount * (10**decimals))
 
 
+def bps_to_chain_units(bps: int | float) -> int:
+    """Convert basis points (bps) to chain units for builder fees.
+
+    The contract uses FEE_PRECISION = 10000 to represent 1%.
+    Since a basis point is 1/100th of a percent, multiply by 100.
+
+    Args:
+        bps: Basis point value (e.g. 10 for 0.1%)
+
+    Returns:
+        Chain units as integer (e.g. 10 bps -> 1000)
+    """
+    return round(bps * 100)
+
+
 def chain_units_to_amount(chain_units: int, decimals: int = 6) -> float:
     """Convert chain units to a decimal amount (e.g., 5670000 -> 5.67)."""
     return chain_units / (10**decimals)

src/decibel/write/__init__.py

@@ -16,6 +16,7 @@
 from decibel._subaccount_types import RenameSubaccount, RenameSubaccountArgs
 from decibel._transaction_builder import InputEntryFunctionData
 from decibel._utils import (
+    bps_to_chain_units,
     get_market_addr,
     get_primary_subaccount_addr,
     post_request,
@@ -270,6 +271,9 @@ async def place_order(
                 if sl_limit_price is not None and tick_size
                 else sl_limit_price
             )
+            final_builder_fee = (
+                bps_to_chain_units(builder_fee) if builder_fee is not None else None
+            )
 
             pkg = self._config.deployment.package
 
@@ -293,7 +297,7 @@ async def _send(addr: str) -> dict[str, Any]:
                             final_sl_trigger,
                             final_sl_limit,
                             builder_addr,
-                            builder_fee,
+                            final_builder_fee,
                         ],
                     ),
                     account_override,
@@ -359,6 +363,9 @@ async def place_twap_order(
     ) -> PlaceOrderResult:
         market_addr = get_market_addr(market_name, self._config.deployment.perp_engine_global)
         pkg = self._config.deployment.package
+        final_builder_fees = (
+            bps_to_chain_units(builder_fees) if builder_fees is not None else None
+        )
 
         async def _send(addr: str) -> dict[str, Any]:
             return await self._send_tx(
@@ -375,7 +382,7 @@ async def _send(addr: str) -> dict[str, Any]:
                         twap_frequency_seconds,
                         twap_duration_seconds,
                         builder_address,
-                        builder_fees,
+                        final_builder_fees,
                     ],
                 ),
                 account_override,
@@ -1049,17 +1056,18 @@ async def approve_max_builder_fee(
         self,
         *,
         builder_addr: str,
-        max_fee: int,
+        max_fee: int | float,
         subaccount_addr: str | None = None,
     ) -> dict[str, Any]:
         pkg = self._config.deployment.package
+        final_max_fee = bps_to_chain_units(max_fee)
 
         async def _send(addr: str) -> dict[str, Any]:
             return await self._send_tx(
                 InputEntryFunctionData(
                     function=f"{pkg}::dex_accounts_entry::approve_max_builder_fee_for_subaccount",
                     type_arguments=[],
-                    function_arguments=[addr, builder_addr, max_fee],
+                    function_arguments=[addr, builder_addr, final_max_fee],
                 )
             )
 
@@ -1302,6 +1310,9 @@ def place_order(
                 if sl_limit_price is not None and tick_size
                 else sl_limit_price
             )
+            final_builder_fee = (
+                bps_to_chain_units(builder_fee) if builder_fee is not None else None
+            )
 
             pkg = self._config.deployment.package
 
@@ -1325,7 +1336,7 @@ def _send(addr: str) -> dict[str, Any]:
                             final_sl_trigger,
                             final_sl_limit,
                             builder_addr,
-                            builder_fee,
+                            final_builder_fee,
                         ],
                     ),
                     account_override,
@@ -1391,6 +1402,9 @@ def place_twap_order(
     ) -> PlaceOrderResult:
         market_addr = get_market_addr(market_name, self._config.deployment.perp_engine_global)
         pkg = self._config.deployment.package
+        final_builder_fees = (
+            bps_to_chain_units(builder_fees) if builder_fees is not None else None
+        )
 
         def _send(addr: str) -> dict[str, Any]:
             return self._send_tx(
@@ -1407,7 +1421,7 @@ def _send(addr: str) -> dict[str, Any]:
                         twap_frequency_seconds,
                         twap_duration_seconds,
                         builder_address,
-                        builder_fees,
+                        final_builder_fees,
                     ],
                 ),
                 account_override,
@@ -2077,17 +2091,18 @@ def approve_max_builder_fee(
         self,
         *,
         builder_addr: str,
-        max_fee: int,
+        max_fee: int | float,
         subaccount_addr: str | None = None,
     ) -> dict[str, Any]:
         pkg = self._config.deployment.package
+        final_max_fee = bps_to_chain_units(max_fee)
 
         def _send(addr: str) -> dict[str, Any]:
             return self._send_tx(
                 InputEntryFunctionData(
                     function=f"{pkg}::dex_accounts_entry::approve_max_builder_fee_for_subaccount",
                     type_arguments=[],
-                    function_arguments=[addr, builder_addr, max_fee],
+                    function_arguments=[addr, builder_addr, final_max_fee],
                 )
             )
 

src/decibel/write/_types.py

@@ -151,7 +151,7 @@ class CancelTpSlOrderArgs(TypedDict):
 
 class ApproveBuilderFeeArgs(TypedDict):
     builder_addr: str
-    max_fee: int
+    max_fee: int | float
     subaccount_addr: NotRequired[str | None]