# `OneTimeCode`

A code a person types from an app, a text or an email: six to eight digits.

Use it for what arrives on a form. Check it when it arrives and don't keep it. For the secret behind an app, use [`TotpSecret`](/docs/types/type-totp-secret.md).

## Shape

One secret value, with no parts.

## Example

```jadpo
OneTimeCode("287082")
```

In a real app it arrives from outside, such as in a request, rather than as text you write in your code.

`text.parse(raw, as: OneTimeCode)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `28708`, `942870820` or `287 082`.

## Good to know

- It is text, so a leading zero is kept.
- `==` tells you whether two are the same. `<` and `list.sort_by` don't take it.

## In JSON

A string when it arrives, and written redacted when it leaves, in a request, a response or `json.write`:

```json
"<redacted OneTimeCode>"
```

## Details

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

`OneTimeCode` is in the group Security, and has been in Jadpo since 0.1.0.

### Text form

`text.parse` reads one from its text as it is typed. `text.from` and `text.format` don't take it, so nothing writes it.

### How it is stored

It is never stored.

### How it is shown to people

`text.format` doesn't take it: a `OneTimeCode` is never shown.

### Operations

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

</details>