diff --git a/src/memory-manager-base.ts b/src/memory-manager-base.ts
index 9ecb00f..a2578d0 100644
--- a/src/memory-manager-base.ts
+++ b/src/memory-manager-base.ts
@@ -183,9 +183,8 @@ export class MemoryManager {
    * Save a memory with dual-write (structured data + embeddings)
    */
 async saveMemory(options: MemorySaveOptions): Promise<Memory> {
-      // Complete provenance field-by-field so direct base-class callers get the
-      // same guarantees as the public MemoryManager facade. Caller-supplied
-      // values win; only missing fields receive defaults.
+      // Complete provenance field-by-field at the shared persistence boundary.
+      // Caller-supplied values win; only missing fields receive defaults.
       const currentMeta = options.metadata ?? {};
       options = {
         ...options,
diff --git a/src/memory-manager.ts b/src/memory-manager.ts
index 9fe5d6d..c4e4ea4 100644
--- a/src/memory-manager.ts
+++ b/src/memory-manager.ts
@@ -1,29 +1,9 @@
 import { MemoryManager as BaseMemoryManager } from './memory-manager-base.js';
-import type { Memory, MemorySaveOptions } from './types.js';
 
 /**
  * Public MemoryManager facade.
  *
- * Complete provenance metadata field-by-field before delegating to the legacy
- * implementation. Caller-supplied provenance values always win, while missing
- * fields receive the same defaults used for fully-unannotated memories.
+ * Persistence policy, including provenance completion, lives in the base
+ * implementation so every caller follows the same write path.
  */
-export class MemoryManager extends BaseMemoryManager {
-  override async saveMemory(options: MemorySaveOptions): Promise<Memory> {
-    const currentMeta = options.metadata ?? {};
-    const completedOptions: MemorySaveOptions = {
-      ...options,
-      metadata: {
-        source_kind: options.source === 'auto' ? 'transcript' : 'user_supplied',
-        evidence_strength: 'direct_original',
-        source_session_id: options.sessionId,
-        source_agent_id: 'opencode',
-        source_model_id: 'default',
-        source_surface: 'opencode',
-        ...currentMeta,
-      },
-    };
-
-    return super.saveMemory(completedOptions);
-  }
-}
+export class MemoryManager extends BaseMemoryManager {}
diff --git a/test/provenance-default-completion.test.ts b/test/provenance-default-completion.test.ts
index 0a0fd37..da9b97d 100644
--- a/test/provenance-default-completion.test.ts
+++ b/test/provenance-default-completion.test.ts
@@ -1,6 +1,7 @@
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
 import { MemoryManager } from '../src/memory-manager.js';
+import { MemoryManager as BaseMemoryManager } from '../src/memory-manager-base.js';
 
 function makeHarness() {
   const pool = {
@@ -62,6 +63,10 @@ async function saveWith(metadata: Record<string, unknown>, source: 'manual' | 'a
 }
 
 describe('MemoryManager provenance default completion', () => {
+  it('inherits the base saveMemory implementation instead of duplicating persistence policy', () => {
+    assert.equal(MemoryManager.prototype.saveMemory, BaseMemoryManager.prototype.saveMemory);
+  });
+
   it('fills missing provenance fields when only source_kind is supplied', async () => {
     const governance = {
       failure_mode: 'repeat mistake',