> ## Documentation Index
> Fetch the complete documentation index at: https://invoca-5bd45748-mintlify-6c3474a6.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Radio

> Divergences, open decisions, and undocumented gaps for Radio.

See [Radio](/invoca-design-system/components/forms/radio) for the decided part of this page.

## Known issues

| ID                                                                                | Kind          | What                                                                                                      |
| --------------------------------------------------------------------------------- | ------------- | --------------------------------------------------------------------------------------------------------- |
| [**TITAN-GAP-32**](/invoca-design-system/foundations/open-decisions#titan-gap-32) | Open decision | Multiple independent disabled-opacity values exist across the Forms group, with no rule for which applies |

## Gaps in the current rules

* **No stated default-selection rule** for a mandatory Radio group — see
  [TITAN-RADIO-06](#constraints-titan-should-enforce) below.
* **No rule for a group with only one option** beyond [TITAN-RADIO-05](/invoca-design-system/components/forms/radio#constraints) saying it
  shouldn't happen — what to do if it does (render anyway, warn, fall back to something else)
  is unstated.
* **Whether a hand-assembled RadioGroup is a documented anti-pattern is unconfirmed.** Input,
  Select, and Checkbox each have a named `DoNotUse_Raw*` story in source explicitly calling out
  bypassing `FormInput`. No equivalent story exists for Radio. This may mean it was never
  flagged, or that raw `RadioGroup` composition is considered acceptable for a reason not
  written down anywhere checked. Do not assume either answer.

## Constraints Titan should enforce

These are real, currently-true rules. Nothing in code stops a builder from violating them today —
each is a placeholder for a guardrail Titan hasn't built, not a decision still being made.

| ID                 | Constraint                                                            | Would be enforced by                                    |
| ------------------ | --------------------------------------------------------------------- | ------------------------------------------------------- |
| **TITAN-RADIO-02** | A Radio group is exposed as a named set.                              | A required group name/`aria-label`.                     |
| **TITAN-RADIO-03** | No visible label → an explicit accessible name is required.           | A required accessible-name prop; a11y lint.             |
| **TITAN-RADIO-04** | A disabled Radio is paired with a reachable explanation.              | A required-when-disabled explanation prop.              |
| **TITAN-RADIO-05** | A Radio group never has exactly one option.                           | A lint/runtime check flagging `options.length === 1`.   |
| **TITAN-RADIO-06** | A required group ships with a default selection (needs confirmation). | A required `defaultValue` prop when `required` is true. |