# Universal Router Commands (/docs/protocols/universal-router/concepts/commands)

Reference Uniswap Universal Router command encoding, supported v2 commands, and composition patterns for execute flows.

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:

```solidity
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:

| 7   | 0 to 6    |
| --- | --------- |
| `f` | `command` |

* `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 | Name                          |
| ------: | ----------------------------- |
|  `0x00` | `V3_SWAP_EXACT_IN`            |
|  `0x01` | `V3_SWAP_EXACT_OUT`           |
|  `0x02` | `PERMIT2_TRANSFER_FROM`       |
|  `0x03` | `PERMIT2_PERMIT_BATCH`        |
|  `0x04` | `SWEEP`                       |
|  `0x05` | `TRANSFER`                    |
|  `0x06` | `PAY_PORTION`                 |
|  `0x08` | `V2_SWAP_EXACT_IN`            |
|  `0x09` | `V2_SWAP_EXACT_OUT`           |
|  `0x0a` | `PERMIT2_PERMIT`              |
|  `0x0b` | `WRAP_ETH`                    |
|  `0x0c` | `UNWRAP_WETH`                 |
|  `0x0d` | `PERMIT2_TRANSFER_FROM_BATCH` |
|  `0x0e` | `BALANCE_CHECK_ERC20`         |
|  `0x10` | `V4_SWAP`                     |
|  `0x11` | `V3_POSITION_MANAGER_PERMIT`  |
|  `0x12` | `V3_POSITION_MANAGER_CALL`    |
|  `0x13` | `V4_INITIALIZE_POOL`          |
|  `0x14` | `V4_POSITION_MANAGER_CALL`    |
|  `0x21` | `EXECUTE_SUB_PLAN`            |

## 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](/docs/protocols/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:

```solidity
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](https://github.com/Uniswap/universal-router)
* [Commands.sol](https://github.com/Uniswap/universal-router/blob/main/contracts/libraries/Commands.sol)
* [Universal Router legacy v1.6.0](https://github.com/Uniswap/universal-router/tree/v1.6.0)