Universal Router Commands

Transactions to UniversalRouter are expressed as a compact command stream. Each command maps to an operation module and reads one ABI-encoded item from inputs[i].

Execution Entry Points

Most integrations run through one of these execute overloads:

execute(bytes calldata commands, bytes[] calldata inputs, uint256 deadline)
execute(bytes calldata commands, bytes[] calldata inputs)

Both overloads process the same command stream. The deadline overload adds a timestamp guard.

UniversalRouter also exposes executeSigned(...), which sets signature context, validates the signature payload, and then routes into execute(commands, inputs).

Command Byte Encoding

Each command is 1 byte with this layout:

• f: allow-revert flag. If set, a failed command does not revert the full transaction.
• command: 7-bit command identifier (commandType & 0x7f in dispatcher logic).

Undefined command values revert with InvalidCommandType.

Supported Commands (v2)

Command Groups

Swaps

• V3_SWAP_EXACT_IN, V3_SWAP_EXACT_OUT, V2_SWAP_EXACT_IN, V2_SWAP_EXACT_OUT, and V4_SWAP.
• Input payloads include recipient, amount bounds, and route/path data.
• V4_SWAP uses action bytes and params arrays that route to v4 swap and settlement handlers.

Permit2 operations

• PERMIT2_TRANSFER_FROM, PERMIT2_TRANSFER_FROM_BATCH, PERMIT2_PERMIT, and PERMIT2_PERMIT_BATCH.
• These commands configure or consume signature-based transfer permissions.
• For signature and allowance semantics, see Permit2 Overview.

Payments and balance checks

• SWEEP, TRANSFER, PAY_PORTION, WRAP_ETH, UNWRAP_WETH, and BALANCE_CHECK_ERC20.
• These commands settle router-held balances and enforce post-condition checks.
• Typical patterns include cleaning residual balances after partial fills.

Position and sub-plan operations

• V3_POSITION_MANAGER_PERMIT, V3_POSITION_MANAGER_CALL, V4_INITIALIZE_POOL, V4_POSITION_MANAGER_CALL, and EXECUTE_SUB_PLAN.
• These commands support liquidity workflows and nested execution plans.
• EXECUTE_SUB_PLAN is useful for conditional branches and fallback sub-flows.

Safety Patterns

If you need partial-fill behavior, set the high bit on a command:

command = 0x80 | 0x00; // V3_SWAP_EXACT_IN with allow-revert

When allow-revert is used, include cleanup commands such as SWEEP to avoid stranded balances in the router.

References

• Universal Router repository
• Commands.sol
• Universal Router legacy v1.6.0