# Return structured output

Every Task says what it **Returns**: plain text, fields you name, or JSON of any shape. Facet holds every answer to that shape, so your code can parse it the same way every time.

## Pick the shape

On the draft, open **Returns** and choose **Text**, **Fields** or **JSON**:

| Returns | Answers look like | Use it for |
|---|---|---|
| Text | `Refund issued on 3 March.` | Rewriting, summaries, replies |
| Fields | `{"label": "billing", "urgent": true}` | Labels, extraction, anything your code reads |
| JSON | Any JSON object | Answers whose shape each input sets, such as "pull out whatever fields this form has" |

Describe each field in a few words: Facet uses the description when it writes examples and checks answers. A field can be text, one of a list of values, yes or no, a number, a whole number, a score from 0 to 1, a date and time, a link, or a list of text. Mark a field optional when an answer may leave it out.

## Read the answer

The answer is in the message content, as JSON text. Parse it as usual:

```python
import json

reply = client.chat.completions.create(
    model="invoice-fields",
    messages=[{"role": "user", "content": invoice_text}],
)
fields = json.loads(reply.choices[0].message.content)
print(fields["total"])
```

```typescript
const reply = await client.chat.completions.create({
  model: "invoice-fields",
  messages: [{ role: "user", content: invoiceText }],
});
const fields = JSON.parse(reply.choices[0].message.content ?? "{}");
console.log(fields.total);
```

You don't send a `response_format`: Facet adds the Task's shape to every call. A Task that returns **JSON** also takes your own `response_format`, of type `json_object` or `json_schema`, to set the shape for one call; a **Text** Task takes one too. A **Fields** Task always answers in its own fields.

## Change the shape later

You can add a field to what a Task returns at any time; callers that ignore it keep working. Removing or renaming a field would break callers, so for that make a new Task, with its own name and its own v1 build.

## Next steps

- [Call a Task](/docs/call): every parameter a call takes
- [Write good Expectations](/docs/expectations): check the values, not just the shape