> ## Documentation Index
> Fetch the complete documentation index at: https://darknyx.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Constrain how an order fills (all-or-none and minimum fill size) independent of its type and time in force.

# Execution attributes

# Execution Attributes

<Info>
  **TL;DR**

  Execution attributes constrain *how* an order fills, on top of its type. Darknyx
  supports a **minimum fill size** (reject any execution smaller than a threshold)
  and **all-or-none**, which is the special case where the threshold equals the full
  order amount.
</Info>

## Minimum fill size

```text theme={null}
min_fill_size: <integer base units>
```

`min_fill_size` rejects any single execution smaller than the given amount. A
batch may only include the order if it can fill at least `min_fill_size` of it.
Use it to avoid being filled in dust-sized increments, useful when each fill
produces a change note you would rather not accumulate.

* Default `0`: any partial fill is acceptable.
* Set it to a positive value to require executions of at least that size.

## All-or-None (AON)

All-or-none is `min_fill_size == amount`: the order fills *completely* or not at
all in any given batch. Because it is expressed through `min_fill_size`, an AON
order can still **rest**: a limit order with `min_fill_size = amount` keeps
waiting, batch after batch, until one batch can fill it whole at its price.

```text theme={null}
amount = 100, min_fill_size = 100   →  fills 100 or nothing, but keeps resting
```

This is the resting cousin of [FOK](./order-types.mdx#fok): FOK demands whole
execution *immediately* and is dropped otherwise; an AON limit demands whole
execution but is patient.

## AON vs. min\_fill\_size

| You want                                   | Set                                  |
| ------------------------------------------ | ------------------------------------ |
| Accept any partial fill                    | `min_fill_size = 0` (default)        |
| Avoid dust fills, accept larger partials   | `min_fill_size = <threshold>`        |
| Fill whole or not at all, but keep waiting | `min_fill_size = amount` (AON limit) |
| Fill whole or not at all, immediately      | `order_type = "fok"`                 |

## Interaction with order type

| Type    | `min_fill_size` honored? | Notes                                                           |
| ------- | ------------------------ | --------------------------------------------------------------- |
| `limit` | Yes                      | The general case; AON is `min_fill_size = amount`.              |
| `ioc`   | Yes                      | Constrains the immediate take; the residual cancels regardless. |
| `fok`   | Implicit                 | FOK is already whole-or-nothing; `min_fill_size` adds nothing.  |

See [Order Compatibility](./order-compatibility.mdx) for the full validity matrix.