# `ChatRole`

Who wrote a message in a conversation with a model: `system`, `user`, `assistant` or `tool`.

Use it as part of a [`ChatMessage`](/docs/types/type-chat-message.md).

## Shape

One of these 4 values:

`ChatRole.system`, `ChatRole.user`, `ChatRole.assistant`, `ChatRole.tool`.

## Example

```jadpo
ChatRole.user
```

`text.parse(raw, as: ChatRole)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `developer`, `model` or `human`.

## Good to know

- `==` tells you whether two are the same. `<` and `list.sort_by` don't take it.

## In JSON

A string, in a request, a response or `json.write`:

```json
"system"
"user"
"assistant"
```

## Details

<details>
<summary>Text form, storage, how it is shown, and operations</summary>

`ChatRole` is in the group AI, and has been in Jadpo since 0.1.0.

### Text form

`text.from` writes one standard text form, the same form `text.parse` reads back: `system`, `user` and `assistant`.

### How it is stored

It is stored in one column named for the field, of type `text`. `assistant` is stored as `'assistant'`.

### How it is shown to people

`text.format(value, locale:)` shows it to people in their locale.

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `system` | `system` |
| `user` | `user` |
| `assistant` | `assistant` |
| `tool` | `tool` |

### Operations

It also takes `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. [How every standard type behaves](/docs/every-standard-type-meets-one-contract.md) says how they work.

</details>