diff --git a/app/Domain/Memory/Actions/StoreMemoryAction.php b/app/Domain/Memory/Actions/StoreMemoryAction.php
index ba89de27..e21e40f7 100644
--- a/app/Domain/Memory/Actions/StoreMemoryAction.php
+++ b/app/Domain/Memory/Actions/StoreMemoryAction.php
@@ -163,7 +163,7 @@ private function normalizeRejectedAlternatives(array $raw): array
      */
     private function storeChunk(
         string $teamId,
-        string $agentId,
+        ?string $agentId,
         string $chunk,
         string $sourceType,
         ?string $projectId,
@@ -225,7 +225,7 @@ private function storeChunk(
      */
     private function evaluateWriteGate(
         string $teamId,
-        string $agentId,
+        ?string $agentId,
         string $contentHash,
         string $embedding,
     ): WriteGateResult {
@@ -304,7 +304,7 @@ private function handleUpdate(
         string $newContent,
         string $newEmbedding,
         string $teamId,
-        string $agentId,
+        ?string $agentId,
         float $newConfidence,
         float $newImportance,
         array $newTags,
@@ -347,7 +347,7 @@ private function handleUpdate(
 
     private function handleAdd(
         string $teamId,
-        string $agentId,
+        ?string $agentId,
         string $chunk,
         string $embedding,
         string $contentHash,
@@ -409,7 +409,7 @@ private function handleAdd(
     /**
      * LLM-assisted merge of two related facts.
      */
-    private function mergeContent(string $existing, string $new, string $teamId, string $agentId): ?string
+    private function mergeContent(string $existing, string $new, string $teamId, ?string $agentId): ?string
     {
         if (! $this->gateway) {
             return null;
diff --git a/tests/Unit/Domain/Memory/Actions/StoreMemoryActionTest.php b/tests/Unit/Domain/Memory/Actions/StoreMemoryActionTest.php
index 94e99012..ef911f67 100644
--- a/tests/Unit/Domain/Memory/Actions/StoreMemoryActionTest.php
+++ b/tests/Unit/Domain/Memory/Actions/StoreMemoryActionTest.php
@@ -35,6 +35,28 @@ public function test_chunk_content_splits_long_content_by_paragraphs(): void
         $this->assertStringContainsString('A', $chunks[0]);
     }
 
+    public function test_team_level_memory_accepts_a_null_agent_id(): void
+    {
+        // execute() advertises `?string $agentId`, but storeChunk() and the
+        // write-gate helpers below it declared a non-nullable `string`. Every
+        // team-scoped write — DistillTeamEventsAction passes `agentId: null`
+        // explicitly — therefore threw a TypeError that execute()'s catch
+        // swallowed into a Log::warning, so nothing was ever stored and no
+        // error surfaced. Production had 0 rows in `memories`.
+        $action = new StoreMemoryAction;
+
+        foreach (['storeChunk', 'evaluateWriteGate', 'handleUpdate', 'handleAdd', 'mergeContent'] as $name) {
+            $param = collect((new \ReflectionMethod($action, $name))->getParameters())
+                ->firstWhere(fn (\ReflectionParameter $p) => $p->getName() === 'agentId');
+
+            $this->assertNotNull($param, "{$name}() should take an \$agentId");
+            $this->assertTrue(
+                $param->getType()?->allowsNull(),
+                "{$name}() must accept a null \$agentId — team-scoped memories have no agent",
+            );
+        }
+    }
+
     public function test_execute_returns_empty_array_when_content_is_empty(): void
     {
         $action = new StoreMemoryAction;