# Khan API Reference

These are the tasks Khan can be passed and the gifts it can give.

## Tasks <a href="#tasks" id="tasks"></a>

Here are the tasks you can pass Khan. You'd either use [`%fard`](#fard) to run a thread from a file or [`%lard`](#lard) to run an in-line thread.

### `%fard` <a href="#fard" id="fard"></a>

Run a thread from within Arvo.

```hoon
[%fard p=(fyrd cage)]
```

`.p` contains the thread location, name, and start arguments. See the [`+fyrd`](https://docs.urbit.org/urbit-os/kernel/types#fyrd) data type reference entry for details.

#### Returns

When the thread finishes, either by succeeding or failing, Khan will return an [`%arow`](#arow) gift.

***

### `%fyrd` <a href="#fyrd" id="fyrd"></a>

External thread.

```hoon
[%fyrd p=(fyrd cast)]
```

This is passed to Khan by the runtime when a thread is run externally. You would not use this from userspace.

***

### `%lard` <a href="#lard" id="lard"></a>

In-line thread.

```hoon
[%lard =bear =shed]
```

The [`$bear`](https://docs.urbit.org/urbit-os/kernel/types#bear) is either a `$desk` or `$beak`. The `$shed` is the thread itself. Since Spider doesn't need to read out the thread from Clay, the `$bear` doesn't do much apart from be included in the thread name that Spider generates. Khan will have Spider run the given thread, and eventually give an [`%arow`](#arow) gift back with the result.

#### Returns

When the thread eventually finishes (or if it fails), Khan with give an [`%arow`](#arow) gift back with the result.

***

## Gifts <a href="#gifts" id="gifts"></a>

These are the two gifts Khan can give. In userspace, you'd only receive an [`%arow`](#arow).

### `%arow` <a href="#arow" id="arow"></a>

In-arvo result.

```hoon
[%arow p=(avow cage)]
```

This gift contains the result of a finished thread if successful, or an error and stack trace if it failed. It's given for threads run from within Arvo. See the [`+avow`](https://docs.urbit.org/urbit-os/kernel/types#avow) entry in the types reference for more details.

***

### `%avow` <a href="#avow" id="avow"></a>

External result.

```hoon
[%avow p=(avow page)]
```

This gift contains the result of running a thread externally. You would not receive this in userspace.

A `$page` is a pair of `$mark` and `$noun`. See the [`+avow`](https://docs.urbit.org/urbit-os/kernel/types#avow) entry in the types reference for more details of that mold builder.

***