This API returns every negative keyword configured across all ad groups of the specified campaign. Negative keywords are supported on keyword-bidded campaign types (SP Auto and SP Manual) that use an allowed bidding strategy; unsupported campaign types return an empty array.

The keywordText field in the response is returned as it is currently stored. Negative keywords created after the Polaris normalization rollout are stored in canonical form (whitespace collapsed, punctuation stripped, lowercase); legacy rows created before the rollout remain in lowercase form until the one-time backfill runs. No normalization is applied on read.