diff --git a/test/antithesis/harness/src/config.rs b/test/antithesis/harness/src/config.rs
index 0c49cd5597..5876c4a741 100644
--- a/test/antithesis/harness/src/config.rs
+++ b/test/antithesis/harness/src/config.rs
@@ -162,6 +162,9 @@ pub(crate) struct V3SeriesConfig {
     enabled: &'static str,
 }
 
+/// Cloud provider kinds sampled into `provider_kind`. The empty string emits no tag.
+const PROVIDER_KINDS: &[&str] = &["", "gke-autopilot", "gke-gdc"];
+
 /// Agent-facing config. `hostname`, `api_key`, `dd_url`, and the socket are
 /// supplied by the environment; `log_level`, the series intake API, and the
 /// `DogStatsD` options are sampled per branch. The static flags are appended by
@@ -184,6 +187,9 @@ pub struct DatadogConfig {
     /// ADP's safety gate for authoritative v3 series, which the Agent has no counterpart for.
     /// Sampled with [`Self::use_v3_api`] so ADP and the Agent never split encodings in a timeline.
     data_plane_metrics_v3_series_enabled: bool,
+    /// Cloud provider kind, sampled per timeline.
+    #[serde(skip_serializing_if = "String::is_empty")]
+    provider_kind: String,
     /// `DogStatsD` options, flattened to top-level `dogstatsd_*` keys.
     #[serde(flatten)]
     dogstatsd: DogStatsdConfig,
@@ -210,6 +216,7 @@ impl DatadogConfig {
             },
             serializer_compressor_kind: rng.random(),
             data_plane_metrics_v3_series_enabled: series_v3,
+            provider_kind: PROVIDER_KINDS[rng.random_range(0..PROVIDER_KINDS.len())].to_owned(),
             dogstatsd: DogStatsdConfig::sample(rng, dogstatsd_socket),
         }
     }