diff --git a/Cargo.lock b/Cargo.lock
index 649153ef5..f64b67e06 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6766,6 +6766,7 @@ dependencies = [
  "uuid",
  "webauthn-authenticator-rs",
  "webauthn-rs",
+ "wip-protocol",
  "workdir",
  "worker",
  "worker-runtime",
diff --git a/crates/workspace-server/Cargo.toml b/crates/workspace-server/Cargo.toml
index 1f5f4f66a..7b50a34cf 100644
--- a/crates/workspace-server/Cargo.toml
+++ b/crates/workspace-server/Cargo.toml
@@ -56,6 +56,7 @@ zeroize.workspace = true
 webauthn-rs = { workspace = true }
 
 [dev-dependencies]
+wip-protocol.workspace = true
 agen.workspace = true
 tempfile.workspace = true
 tools.workspace = true
diff --git a/crates/workspace-server/src/server_workspace_config_wip_tests.rs b/crates/workspace-server/src/server_workspace_config_wip_tests.rs
index c0df1d1a5..11f3842ba 100644
--- a/crates/workspace-server/src/server_workspace_config_wip_tests.rs
+++ b/crates/workspace-server/src/server_workspace_config_wip_tests.rs
@@ -139,26 +139,27 @@ impl worker::WorkspaceClient for ConfigRouterClient {
         Ok(response)
     }
 }
-fn config_interface(path: &str) -> String {
-    // Use the published contextual interface identity, not a model-managed validator.
-    let hex = path
-        .bytes()
-        .map(|byte| format!("{byte:02x}"))
-        .collect::<String>();
-    format!("yoi.workspace-config/node/v1/@/{hex}")
+fn config_interface(path: &str) -> wip_protocol::InterfaceReference {
+    // Use the published structured Interface identity, not a model-managed validator.
+    wip_protocol::InterfaceReference {
+        scope: path.into(),
+        name: "yoi.workspace-config/node/v1".into(),
+    }
 }
-async fn config_discover(runtime: &worker::wip::WipRuntime, path: &str) {
-    let observed = runtime
-        .discover(path.into(), 0, true)
-        .await
-        .unwrap()
-        .content
-        .unwrap();
+async fn config_inspect(runtime: &worker::wip::WipRuntime, path: &str) {
+    let output = runtime.inspect(path.into(), true).await.unwrap();
+    let observed: Value = serde_json::from_str(output.content.as_deref().unwrap()).unwrap();
     assert!(
-        observed.contains(&config_interface(path)),
-        "interface must come from live discovery: {observed}"
+        observed["interfaces"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .any(|interface| {
+                interface["reference"]
+                    == json!({"scope": path, "name": config_interface(path).name})
+            }),
+        "Interface must come from live Object inspection: {observed}"
     );
-    runtime.inspect(config_interface(path), true).await.unwrap();
 }
 async fn config_call(
     runtime: &worker::wip::WipRuntime,
@@ -167,7 +168,7 @@ async fn config_call(
     args: Value,
 ) -> std::result::Result<agen::tool::ToolOutput, agen::tool::ToolError> {
     runtime
-        .call(
+        .invoke(
             path.into(),
             config_interface(path),
             operation.into(),
@@ -183,23 +184,24 @@ async fn catalog_call(
     base: &str,
     operation: &str,
 ) -> Value {
-    let hex = path
-        .bytes()
-        .map(|byte| format!("{byte:02x}"))
-        .collect::<String>();
-    let interface = format!("{base}/@/{hex}");
-    let discovered = runtime
-        .discover(path.into(), 0, true)
-        .await
-        .unwrap()
-        .content
-        .unwrap();
-    assert!(discovered.contains(&interface), "{discovered}");
-    runtime.inspect(interface.clone(), true).await.unwrap();
+    let interface = json!({"scope": path, "name": base});
+    let inspected = runtime.inspect(path.into(), true).await.unwrap();
+    let observed: Value = serde_json::from_str(inspected.content.as_deref().unwrap()).unwrap();
+    assert!(
+        observed["interfaces"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .any(|published| published["reference"] == interface),
+        "{observed}"
+    );
     let output = runtime
-        .call(
+        .invoke(
             path.into(),
-            interface,
+            wip_protocol::InterfaceReference {
+                scope: path.into(),
+                name: base.into(),
+            },
             operation.into(),
             json!({}),
             agen::tool::ToolExecutionContext::direct(),
@@ -378,7 +380,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
             .connection_id,
         attached.connection_id
     );
-    config_discover(&wip, CONTENT_ROOT).await;
+    config_inspect(&wip, CONTENT_ROOT).await;
     config_call(
         &wip,
         CONTENT_ROOT,
@@ -388,7 +390,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
     .await
     .unwrap();
     let path = "/workspace-config/notes/wip.md";
-    config_discover(&wip, path).await;
+    config_inspect(&wip, path).await;
     assert!(
         config_call(&wip, path, "read", json!({}))
             .await
@@ -422,7 +424,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
     config_call(&wip, path, "write", json!({"content":"replacement note"}))
         .await
         .unwrap();
-    config_discover(&wip, CONTENT_ROOT).await;
+    config_inspect(&wip, CONTENT_ROOT).await;
     config_call(&wip,CONTENT_ROOT,"apply_changes",json!({"changes":[
         {"kind":"create","path":"fragments/prompts.dcdl","content_type":"decodal","content":"{ common = { language = \"CONFIG_WIP_E2E\"; }; }"},
         {"kind":"update","path":"main.dcdl","content":"{ prompts = import \"./fragments/prompts.dcdl\"; } as WorkspaceConfigSchema"}
@@ -436,7 +438,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
         .unwrap();
     let prompts = crate::prompt_settings::project_prompts_from_workspace_config(&state).unwrap();
     assert_eq!(prompts.templates["common.language"], "CONFIG_WIP_E2E");
-    config_discover(&wip, path).await;
+    config_inspect(&wip, path).await;
     config_call(&wip, path, "delete", json!({})).await.unwrap();
     assert!(
         fixture
@@ -449,7 +451,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
             .get(&config_source::VirtualPath::parse("notes/wip.md").unwrap())
             .is_none()
     );
-    config_discover(&wip, CONTENT_ROOT).await;
+    config_inspect(&wip, CONTENT_ROOT).await;
     let before = fixture
         .api
         .config_store
@@ -492,7 +494,7 @@ async fn workspace_config_real_selected_invoke_backend_wip_edit_create_delete_im
         dispatched + 1,
         "a lost response cannot trigger automatic retry"
     );
-    config_discover(&wip, CONTENT_ROOT).await;
+    config_inspect(&wip, CONTENT_ROOT).await;
     let readonly = workspace_config::attach(
         &fixture.api,
         &fixture.worker,
@@ -633,15 +635,15 @@ async fn assert_config_production_http_adapter(
     )
     .unwrap();
     assert_config_catalog(&wip, &attached).await;
-    config_discover(&wip, "/workspace-config/main.dcdl").await;
+    config_inspect(&wip, "/workspace-config/main.dcdl").await;
     let main_interface = wip
-        .inspect(config_interface("/workspace-config/main.dcdl"), true)
+        .inspect("/workspace-config/main.dcdl".into(), true)
         .await
         .unwrap()
         .content
         .unwrap();
     assert!(
-        !main_interface.contains("\"delete\""),
+        !main_interface.contains("delete("),
         "required entrypoint cannot advertise delete: {main_interface}"
     );
     assert!(
@@ -652,7 +654,7 @@ async fn assert_config_production_http_adapter(
             .unwrap()
             .contains("WorkspaceConfigSchema")
     );
-    config_discover(&wip, "/workspace-config").await;
+    config_inspect(&wip, "/workspace-config").await;
     config_call(
         &wip,
         "/workspace-config",