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

# updateThreadFieldSchema

> Updates an existing thread field schema. All fields except `key` and `type` are mutable. String fields use wrapper inputs (e.g. `{ value: "..." }`) to distinguish a deliberate null from an omitted value. Requires the `threadFieldSchema:edit` permission.