# Update Entity Type Action

Update an existing action's relation mappings.

Endpoint: PATCH /resources/entity-types/v1/{key}/actions/{actionKey}
Version: 1.0
Security: bearer

## Request fields (application/json):

  - `key` (string, required)
    Example: "read"

  - `relationKeys` (array, required)
    Array of relation keys (strings) or arrow syntax objects ({ fromRelation, toAction })
    Example: ["reader","writer",{"fromRelation":"parent","toAction":"read"}]

## Response 200 fields (application/json):

  - `vendorId` (string, required)
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `entityTypeKey` (string, required)
    Example: "book"

  - `key` (string, required)
    Example: "read"

  - `relationKeys` (array, required)
    Example: ["reader","writer",{"fromRelation":"parent","toAction":"read"}]