> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cow.bleu.builders/llms.txt
> Use this file to discover all available pages before exploring further.

# TWAP

> Time-Weighted Average Price orders that split large trades into multiple smaller executions at fixed intervals.

# TWAP Orders

TWAP (Time-Weighted Average Price) orders enable splitting large trades into multiple smaller executions at fixed intervals, helping reduce price impact and achieve better average prices.

## Core Structure

The TWAP mechanism divides a total trade into `n` equal parts executing every `t` seconds, with each part having a validity window defined by the `span` parameter.

## Key Parameters

| Parameter        | Type      | Purpose                                           |
| ---------------- | --------- | ------------------------------------------------- |
| `sellToken`      | `IERC20`  | Token being sold                                  |
| `buyToken`       | `IERC20`  | Token being purchased                             |
| `receiver`       | `address` | Recipient of bought tokens                        |
| `partSellAmount` | `uint256` | Amount per execution part                         |
| `minPartLimit`   | `uint256` | Minimum buy amount per part                       |
| `t0`             | `uint256` | Start timestamp (0 for dynamic)                   |
| `n`              | `uint256` | Number of parts (>1)                              |
| `t`              | `uint256` | Seconds between parts                             |
| `span`           | `uint256` | Validity window (must be less than or equal to t) |
| `appData`        | `bytes32` | IPFS metadata hash                                |

## Validation Requirements

Orders must satisfy:

* Different sell and buy tokens
* Non-zero addresses
* `partSellAmount` > 0
* `minPartLimit` > 0
* `n` between 2 and `type(uint32).max`
* `t` between 1 and 365 days
* `span` must be less than or equal to `t`

## Validity Window Calculation

With `span = 0`, each part remains valid until the next part begins. When `span > 0`, validity is restricted to that duration. This ensures unique order identifiers preventing duplicate executions.

## Error Conditions

| Error               | Description                                 |
| ------------------- | ------------------------------------------- |
| `BEFORE_TWAP_START` | Current time precedes order start           |
| `AFTER_TWAP_FINISH` | All parts completed                         |
| `NOT_WITHIN_SPAN`   | Current time outside part's validity window |

## Implementation

The contract resides at `/src/types/twap/TWAP.sol`. Key functions include:

* `getTradeableOrder()` - Retrieves the current executable part
* `orderFor()` - Constructs the CoW Protocol order with calculated validity timestamps