# `ChatRole`

Who wrote a message in a conversation with a model.

[AI](types.md#ai); not ordered; since Jadpo 0.1.0.

## Make one

Pick one of its variants, `ChatRole.system`.

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

## Variants

4 variants, each written as its own name: `system`, `user`, `assistant`, `tool`.

## Text, JSON and storage

`text.from` writes its canonical text, the one form `text.parse` reads back. JSON sends its canonical text as a string.

| Text | JSON |
|---|---|
| `system` | `"system"` |
| `user` | `"user"` |
| `assistant` | `"assistant"` |
| `tool` | `"tool"` |

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

## 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 has the contract's own operations: `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. It isn't ordered, so `<` and sorting don't take it. [Every standard type meets one contract](../topics/every-standard-type-meets-one-contract.md) says how they work.