diff --git a/src/agents/pi-embedded-runner/compact.runtime.ts b/src/agents/pi-embedded-runner/compact.runtime.ts
new file mode 100644
index 00000000000..33c4ed7066a
--- /dev/null
+++ b/src/agents/pi-embedded-runner/compact.runtime.ts
@@ -0,0 +1 @@
+export { compactEmbeddedPiSessionDirect } from "./compact.js";
diff --git a/src/context-engine/legacy.ts b/src/context-engine/legacy.ts
index ba05c9e8b8d..ab2eeff9b7f 100644
--- a/src/context-engine/legacy.ts
+++ b/src/context-engine/legacy.ts
@@ -69,9 +69,9 @@ export class LegacyContextEngine implements ContextEngine {
     customInstructions?: string;
     legacyParams?: Record<string, unknown>;
   }): Promise<CompactResult> {
-    // Import dynamically to avoid circular dependencies
+    // Import through a dedicated runtime boundary so the lazy edge remains effective.
     const { compactEmbeddedPiSessionDirect } =
-      await import("../agents/pi-embedded-runner/compact.js");
+      await import("../agents/pi-embedded-runner/compact.runtime.js");
 
     // legacyParams carries the full CompactEmbeddedPiSessionParams fields
     // set by the caller in run.ts. We spread them and override the fields