diff --git a/testing-framework/core/src/scenario/definition.rs b/testing-framework/core/src/scenario/definition.rs
index 56190db..83ebed1 100644
--- a/testing-framework/core/src/scenario/definition.rs
+++ b/testing-framework/core/src/scenario/definition.rs
@@ -4,7 +4,7 @@ use thiserror::Error;
 use tracing::{debug, info};
 
 use super::{
-    Application, AttachSource, DeploymentPolicy, DynError, ExternalNodeSource,
+    Application, DeploymentPolicy, DynError, ExistingCluster, ExternalNodeSource,
     HttpReadinessRequirement, NodeControlCapability, ObservabilityCapability, ScenarioSources,
     builder_ops::CoreBuilderAccess,
     expectation::Expectation,
@@ -119,7 +119,7 @@ impl<E: Application, Caps> Scenario<E, Caps> {
     }
 
     #[must_use]
-    pub fn existing_cluster(&self) -> Option<&AttachSource> {
+    pub fn existing_cluster(&self) -> Option<&ExistingCluster> {
         self.sources.existing_cluster()
     }
 
@@ -130,7 +130,7 @@ impl<E: Application, Caps> Scenario<E, Caps> {
 
     #[must_use]
     #[doc(hidden)]
-    pub fn attached_source(&self) -> Option<&AttachSource> {
+    pub fn attached_source(&self) -> Option<&ExistingCluster> {
         self.existing_cluster()
     }
 
@@ -255,13 +255,13 @@ macro_rules! impl_common_builder_methods {
             }
 
             #[must_use]
-            pub fn with_existing_cluster(self, cluster: AttachSource) -> Self {
+            pub fn with_existing_cluster(self, cluster: ExistingCluster) -> Self {
                 self.map_core_builder(|builder| builder.with_existing_cluster(cluster))
             }
 
             #[must_use]
             #[doc(hidden)]
-            pub fn with_attach_source(self, attach: AttachSource) -> Self {
+            pub fn with_attach_source(self, attach: ExistingCluster) -> Self {
                 self.with_existing_cluster(attach)
             }
 
@@ -574,14 +574,14 @@ impl<E: Application, Caps> Builder<E, Caps> {
     }
 
     #[must_use]
-    pub fn with_existing_cluster(mut self, cluster: AttachSource) -> Self {
+    pub fn with_existing_cluster(mut self, cluster: ExistingCluster) -> Self {
         self.sources = self.sources.with_attach(cluster);
         self
     }
 
     #[must_use]
     #[doc(hidden)]
-    pub fn with_attach_source(self, attach: AttachSource) -> Self {
+    pub fn with_attach_source(self, attach: ExistingCluster) -> Self {
         self.with_existing_cluster(attach)
     }
 
diff --git a/testing-framework/core/src/scenario/mod.rs b/testing-framework/core/src/scenario/mod.rs
index 8b570ad..37dc1ef 100644
--- a/testing-framework/core/src/scenario/mod.rs
+++ b/testing-framework/core/src/scenario/mod.rs
@@ -51,7 +51,9 @@ pub use runtime::{
     wait_for_http_ports_with_host_and_requirement, wait_for_http_ports_with_requirement,
     wait_http_readiness, wait_until_stable,
 };
-pub use sources::{AttachSource, ExternalNodeSource, ScenarioSources};
+#[doc(hidden)]
+pub use sources::AttachSource;
+pub use sources::{ExistingCluster, ExternalNodeSource, ScenarioSources};
 pub use workload::Workload;
 
 pub use crate::env::Application;
diff --git a/testing-framework/core/src/scenario/runtime/orchestration/source_orchestration_plan.rs b/testing-framework/core/src/scenario/runtime/orchestration/source_orchestration_plan.rs
index f1dd9b9..2c10958 100644
--- a/testing-framework/core/src/scenario/runtime/orchestration/source_orchestration_plan.rs
+++ b/testing-framework/core/src/scenario/runtime/orchestration/source_orchestration_plan.rs
@@ -1,4 +1,4 @@
-use crate::scenario::{AttachSource, ExternalNodeSource, ScenarioSources};
+use crate::scenario::{ExistingCluster, ExternalNodeSource, ScenarioSources};
 
 /// Explicit descriptor for managed node sourcing.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
@@ -19,7 +19,7 @@ pub(crate) enum SourceOrchestrationMode {
         external: Vec<ExternalNodeSource>,
     },
     Attached {
-        attach: AttachSource,
+        attach: ExistingCluster,
         external: Vec<ExternalNodeSource>,
     },
     ExternalOnly {
@@ -69,11 +69,12 @@ impl SourceOrchestrationPlan {
 #[cfg(test)]
 mod tests {
     use super::{SourceOrchestrationMode, SourceOrchestrationPlan};
-    use crate::scenario::{AttachSource, ScenarioSources};
+    use crate::scenario::{ExistingCluster, ScenarioSources};
 
     #[test]
     fn attached_sources_are_planned() {
-        let sources = ScenarioSources::attached(AttachSource::compose(vec!["node-0".to_string()]));
+        let sources =
+            ScenarioSources::attached(ExistingCluster::compose(vec!["node-0".to_string()]));
         let plan = SourceOrchestrationPlan::try_from_sources(&sources)
             .expect("attached sources should build a source orchestration plan");
 
diff --git a/testing-framework/core/src/scenario/runtime/providers/attach_provider.rs b/testing-framework/core/src/scenario/runtime/providers/attach_provider.rs
index d31bd78..b239193 100644
--- a/testing-framework/core/src/scenario/runtime/providers/attach_provider.rs
+++ b/testing-framework/core/src/scenario/runtime/providers/attach_provider.rs
@@ -1,6 +1,6 @@
 use async_trait::async_trait;
 
-use crate::scenario::{Application, AttachSource, DynError};
+use crate::scenario::{Application, DynError, ExistingCluster};
 
 /// Attached node discovered from an existing external cluster source.
 #[derive(Clone, Debug)]
@@ -15,7 +15,7 @@ pub struct AttachedNode<E: Application> {
 #[derive(Debug, thiserror::Error)]
 pub enum AttachProviderError {
     #[error("attach source is not supported by this provider: {attach_source:?}")]
-    UnsupportedSource { attach_source: AttachSource },
+    UnsupportedSource { attach_source: ExistingCluster },
     #[error("attach discovery failed: {source}")]
     Discovery {
         #[source]
@@ -32,7 +32,7 @@ pub trait AttachProvider<E: Application>: Send + Sync {
     /// Discovers node clients for the requested attach source.
     async fn discover(
         &self,
-        source: &AttachSource,
+        source: &ExistingCluster,
     ) -> Result<Vec<AttachedNode<E>>, AttachProviderError>;
 }
 
@@ -44,7 +44,7 @@ pub struct NoopAttachProvider;
 impl<E: Application> AttachProvider<E> for NoopAttachProvider {
     async fn discover(
         &self,
-        source: &AttachSource,
+        source: &ExistingCluster,
     ) -> Result<Vec<AttachedNode<E>>, AttachProviderError> {
         Err(AttachProviderError::UnsupportedSource {
             attach_source: source.clone(),
diff --git a/testing-framework/core/src/scenario/sources/mod.rs b/testing-framework/core/src/scenario/sources/mod.rs
index 98324dd..26075f2 100644
--- a/testing-framework/core/src/scenario/sources/mod.rs
+++ b/testing-framework/core/src/scenario/sources/mod.rs
@@ -1,3 +1,5 @@
 mod model;
 
-pub use model::{AttachSource, ExternalNodeSource, ScenarioSources};
+#[doc(hidden)]
+pub use model::AttachSource;
+pub use model::{ExistingCluster, ExternalNodeSource, ScenarioSources};
diff --git a/testing-framework/core/src/scenario/sources/model.rs b/testing-framework/core/src/scenario/sources/model.rs
index df444f6..8e62419 100644
--- a/testing-framework/core/src/scenario/sources/model.rs
+++ b/testing-framework/core/src/scenario/sources/model.rs
@@ -1,6 +1,6 @@
 /// Typed attach source for existing clusters.
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub enum AttachSource {
+pub enum ExistingCluster {
     K8s {
         namespace: Option<String>,
         label_selector: String,
@@ -11,7 +11,7 @@ pub enum AttachSource {
     },
 }
 
-impl AttachSource {
+impl ExistingCluster {
     #[must_use]
     pub fn k8s(label_selector: String) -> Self {
         Self::K8s {
@@ -77,6 +77,9 @@ impl AttachSource {
     }
 }
 
+#[doc(hidden)]
+pub type AttachSource = ExistingCluster;
+
 /// Static external node endpoint that should be included in the runtime
 /// inventory.
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -110,7 +113,7 @@ pub enum ScenarioSources {
         external: Vec<ExternalNodeSource>,
     },
     Attached {
-        attach: AttachSource,
+        attach: ExistingCluster,
         external: Vec<ExternalNodeSource>,
     },
     ExternalOnly {
@@ -135,7 +138,7 @@ impl ScenarioSources {
     }
 
     #[must_use]
-    pub fn attached(attach: AttachSource) -> Self {
+    pub fn attached(attach: ExistingCluster) -> Self {
         Self::Attached {
             attach,
             external: Vec::new(),
@@ -159,7 +162,7 @@ impl ScenarioSources {
     }
 
     #[must_use]
-    pub fn with_attach(self, attach: AttachSource) -> Self {
+    pub fn with_attach(self, attach: ExistingCluster) -> Self {
         let external = self.external_nodes().to_vec();
 
         Self::Attached { attach, external }
diff --git a/testing-framework/deployers/compose/src/deployer/attach_provider.rs b/testing-framework/deployers/compose/src/deployer/attach_provider.rs
index 06c8d61..314ae3d 100644
--- a/testing-framework/deployers/compose/src/deployer/attach_provider.rs
+++ b/testing-framework/deployers/compose/src/deployer/attach_provider.rs
@@ -2,8 +2,8 @@ use std::marker::PhantomData;
 
 use async_trait::async_trait;
 use testing_framework_core::scenario::{
-    AttachProvider, AttachProviderError, AttachSource, AttachedNode, ClusterWaitHandle, DynError,
-    ExternalNodeSource, HttpReadinessRequirement, wait_http_readiness,
+    AttachProvider, AttachProviderError, AttachedNode, ClusterWaitHandle, DynError,
+    ExistingCluster, ExternalNodeSource, HttpReadinessRequirement, wait_http_readiness,
 };
 use url::Url;
 
@@ -22,7 +22,7 @@ pub(super) struct ComposeAttachProvider<E: ComposeDeployEnv> {
 
 pub(super) struct ComposeAttachedClusterWait<E: ComposeDeployEnv> {
     host: String,
-    source: AttachSource,
+    source: ExistingCluster,
     _env: PhantomData<E>,
 }
 
@@ -42,7 +42,7 @@ impl<E: ComposeDeployEnv> ComposeAttachProvider<E> {
 }
 
 impl<E: ComposeDeployEnv> ComposeAttachedClusterWait<E> {
-    pub(super) fn new(host: String, source: AttachSource) -> Self {
+    pub(super) fn new(host: String, source: ExistingCluster) -> Self {
         Self {
             host,
             source,
@@ -60,7 +60,7 @@ struct ComposeAttachRequest<'a> {
 impl<E: ComposeDeployEnv> AttachProvider<E> for ComposeAttachProvider<E> {
     async fn discover(
         &self,
-        source: &AttachSource,
+        source: &ExistingCluster,
     ) -> Result<Vec<AttachedNode<E>>, AttachProviderError> {
         let request = compose_attach_request(source)?;
         let services = resolve_services(request.project, request.services)
@@ -85,7 +85,7 @@ fn to_discovery_error(source: DynError) -> AttachProviderError {
 }
 
 fn compose_attach_request(
-    source: &AttachSource,
+    source: &ExistingCluster,
 ) -> Result<ComposeAttachRequest<'_>, AttachProviderError> {
     let services =
         source
@@ -173,7 +173,7 @@ impl<E: ComposeDeployEnv> ClusterWaitHandle<E> for ComposeAttachedClusterWait<E>
     }
 }
 
-fn compose_wait_request(source: &AttachSource) -> Result<ComposeAttachRequest<'_>, DynError> {
+fn compose_wait_request(source: &ExistingCluster) -> Result<ComposeAttachRequest<'_>, DynError> {
     let project = source
         .compose_project()
         .ok_or_else(|| DynError::from("compose cluster wait requires a compose attach source"))?;
diff --git a/testing-framework/deployers/compose/src/deployer/mod.rs b/testing-framework/deployers/compose/src/deployer/mod.rs
index fd6f44a..66859c1 100644
--- a/testing-framework/deployers/compose/src/deployer/mod.rs
+++ b/testing-framework/deployers/compose/src/deployer/mod.rs
@@ -9,7 +9,7 @@ use std::marker::PhantomData;
 
 use async_trait::async_trait;
 use testing_framework_core::scenario::{
-    AttachSource, CleanupGuard, Deployer, DynError, FeedHandle, ObservabilityCapabilityProvider,
+    CleanupGuard, Deployer, DynError, ExistingCluster, FeedHandle, ObservabilityCapabilityProvider,
     RequiresNodeControl, Runner, Scenario,
 };
 
@@ -45,12 +45,12 @@ impl ComposeDeploymentMetadata {
 
     /// Builds an existing-cluster descriptor for the same compose project
     /// using deployer discovery to resolve services.
-    pub fn existing_cluster(&self) -> Result<AttachSource, DynError> {
+    pub fn existing_cluster(&self) -> Result<ExistingCluster, DynError> {
         let project_name = self
             .project_name()
             .ok_or(ComposeMetadataError::MissingProjectName)?;
 
-        Ok(AttachSource::compose_in_project(
+        Ok(ExistingCluster::compose_in_project(
             Vec::new(),
             project_name.to_owned(),
         ))
@@ -60,19 +60,19 @@ impl ComposeDeploymentMetadata {
     pub fn existing_cluster_for_services(
         &self,
         services: Vec<String>,
-    ) -> Result<AttachSource, DynError> {
+    ) -> Result<ExistingCluster, DynError> {
         let project_name = self
             .project_name()
             .ok_or(ComposeMetadataError::MissingProjectName)?;
 
-        Ok(AttachSource::compose_in_project(
+        Ok(ExistingCluster::compose_in_project(
             services,
             project_name.to_owned(),
         ))
     }
 
     #[doc(hidden)]
-    pub fn attach_source(&self) -> Result<AttachSource, DynError> {
+    pub fn attach_source(&self) -> Result<ExistingCluster, DynError> {
         self.existing_cluster()
     }
 
@@ -80,7 +80,7 @@ impl ComposeDeploymentMetadata {
     pub fn attach_source_for_services(
         &self,
         services: Vec<String>,
-    ) -> Result<AttachSource, DynError> {
+    ) -> Result<ExistingCluster, DynError> {
         self.existing_cluster_for_services(services)
     }
 }
diff --git a/testing-framework/deployers/compose/src/deployer/orchestrator.rs b/testing-framework/deployers/compose/src/deployer/orchestrator.rs
index ef93c7f..d9cf18c 100644
--- a/testing-framework/deployers/compose/src/deployer/orchestrator.rs
+++ b/testing-framework/deployers/compose/src/deployer/orchestrator.rs
@@ -3,8 +3,8 @@ use std::{env, sync::Arc, time::Duration};
 use reqwest::Url;
 use testing_framework_core::{
     scenario::{
-        ApplicationExternalProvider, AttachSource, CleanupGuard, ClusterWaitHandle,
-        DeploymentPolicy, FeedHandle, FeedRuntime, HttpReadinessRequirement, Metrics, NodeClients,
+        ApplicationExternalProvider, CleanupGuard, ClusterWaitHandle, DeploymentPolicy,
+        ExistingCluster, FeedHandle, FeedRuntime, HttpReadinessRequirement, Metrics, NodeClients,
         NodeControlHandle, ObservabilityCapabilityProvider, ObservabilityInputs,
         RequiresNodeControl, RunContext, Runner, Scenario, SourceOrchestrationPlan,
         SourceProviders, StaticManagedProvider, build_source_orchestration_plan,
@@ -315,7 +315,7 @@ impl<E: ComposeDeployEnv> DeploymentOrchestrator<E> {
     fn managed_cluster_wait(&self, project_name: String) -> Arc<dyn ClusterWaitHandle<E>> {
         Arc::new(ComposeAttachedClusterWait::<E>::new(
             compose_runner_host(),
-            AttachSource::compose_in_project(Vec::new(), project_name),
+            ExistingCluster::compose_in_project(Vec::new(), project_name),
         ))
     }
 
diff --git a/testing-framework/deployers/k8s/src/deployer/attach_provider.rs b/testing-framework/deployers/k8s/src/deployer/attach_provider.rs
index bae5692..cfa0dc2 100644
--- a/testing-framework/deployers/k8s/src/deployer/attach_provider.rs
+++ b/testing-framework/deployers/k8s/src/deployer/attach_provider.rs
@@ -7,8 +7,8 @@ use kube::{
     api::{ListParams, ObjectList},
 };
 use testing_framework_core::scenario::{
-    AttachProvider, AttachProviderError, AttachSource, AttachedNode, ClusterWaitHandle, DynError,
-    ExternalNodeSource, HttpReadinessRequirement, wait_http_readiness,
+    AttachProvider, AttachProviderError, AttachedNode, ClusterWaitHandle, DynError,
+    ExistingCluster, ExternalNodeSource, HttpReadinessRequirement, wait_http_readiness,
 };
 use url::Url;
 
@@ -37,7 +37,7 @@ pub(super) struct K8sAttachProvider<E: K8sDeployEnv> {
 
 pub(super) struct K8sAttachedClusterWait<E: K8sDeployEnv> {
     client: Client,
-    source: AttachSource,
+    source: ExistingCluster,
     _env: PhantomData<E>,
 }
 
@@ -56,7 +56,7 @@ impl<E: K8sDeployEnv> K8sAttachProvider<E> {
 }
 
 impl<E: K8sDeployEnv> K8sAttachedClusterWait<E> {
-    pub(super) fn new(client: Client, source: AttachSource) -> Self {
+    pub(super) fn new(client: Client, source: ExistingCluster) -> Self {
         Self {
             client,
             source,
@@ -69,7 +69,7 @@ impl<E: K8sDeployEnv> K8sAttachedClusterWait<E> {
 impl<E: K8sDeployEnv> AttachProvider<E> for K8sAttachProvider<E> {
     async fn discover(
         &self,
-        source: &AttachSource,
+        source: &ExistingCluster,
     ) -> Result<Vec<AttachedNode<E>>, AttachProviderError> {
         let request = k8s_attach_request(source)?;
         let services = discover_services(&self.client, request.namespace, request.label_selector)
@@ -90,7 +90,9 @@ fn to_discovery_error(source: DynError) -> AttachProviderError {
     AttachProviderError::Discovery { source }
 }
 
-fn k8s_attach_request(source: &AttachSource) -> Result<K8sAttachRequest<'_>, AttachProviderError> {
+fn k8s_attach_request(
+    source: &ExistingCluster,
+) -> Result<K8sAttachRequest<'_>, AttachProviderError> {
     let Some(label_selector) = source.k8s_label_selector() else {
         return Err(AttachProviderError::UnsupportedSource {
             attach_source: source.clone(),
@@ -242,7 +244,7 @@ impl<E: K8sDeployEnv> ClusterWaitHandle<E> for K8sAttachedClusterWait<E> {
     }
 }
 
-fn k8s_wait_request(source: &AttachSource) -> Result<K8sAttachRequest<'_>, DynError> {
+fn k8s_wait_request(source: &ExistingCluster) -> Result<K8sAttachRequest<'_>, DynError> {
     let label_selector = source
         .k8s_label_selector()
         .ok_or_else(|| DynError::from("k8s cluster wait requires a k8s attach source"))?;
diff --git a/testing-framework/deployers/k8s/src/deployer/mod.rs b/testing-framework/deployers/k8s/src/deployer/mod.rs
index a43b83c..eae7507 100644
--- a/testing-framework/deployers/k8s/src/deployer/mod.rs
+++ b/testing-framework/deployers/k8s/src/deployer/mod.rs
@@ -2,7 +2,7 @@ mod attach_provider;
 mod orchestrator;
 
 pub use orchestrator::{K8sDeployer, K8sRunnerError};
-use testing_framework_core::scenario::{AttachSource, DynError};
+use testing_framework_core::scenario::{DynError, ExistingCluster};
 
 /// Kubernetes deployment metadata returned by k8s-specific deployment APIs.
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -35,20 +35,20 @@ impl K8sDeploymentMetadata {
     }
 
     /// Builds an existing-cluster descriptor for the same k8s deployment scope.
-    pub fn existing_cluster(&self) -> Result<AttachSource, DynError> {
+    pub fn existing_cluster(&self) -> Result<ExistingCluster, DynError> {
         let namespace = self.namespace().ok_or(K8sMetadataError::MissingNamespace)?;
         let label_selector = self
             .label_selector()
             .ok_or(K8sMetadataError::MissingLabelSelector)?;
 
-        Ok(AttachSource::k8s_in_namespace(
+        Ok(ExistingCluster::k8s_in_namespace(
             label_selector.to_owned(),
             namespace.to_owned(),
         ))
     }
 
     #[doc(hidden)]
-    pub fn attach_source(&self) -> Result<AttachSource, DynError> {
+    pub fn attach_source(&self) -> Result<ExistingCluster, DynError> {
         self.existing_cluster()
     }
 }