> ## Documentation Index
> Fetch the complete documentation index at: https://docs.automate.ax/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Automate.ax automations are TypeScript programs.
> Use Bun for installation and command examples.
> Use Automate.ax for the product name and automate.ax for the package, CLI, and domain.
> Treat documented public APIs as current; do not invent transitional or deprecated names.

# List board Custom Fields

> List Custom Field definitions on a Trello board.

`trello.listBoardCustomFields` lists the Custom Field definitions available to cards on one board.

```ts automations/list-trello-custom-fields.automation.ts theme={null}
import { automation, onDashboardRun } from "automate.ax"
import { trello } from "automate.ax/trello"

export default automation("List Trello Custom Fields", () => {
  onDashboardRun({ title: "List Trello Custom Fields" })
  trello.listBoardCustomFields({ board: "board-id" })
})
```

Provide `board` as an ID, short link, or standard board URL. Optional second argument `{ account }` selects a Trello binding.

Returns `Signal<TrelloCustomField[]>`, including each definition's ID, board model ID, name, type, position, card-front display setting, optional field group, and dropdown options.