diff --git a/.gitignore b/.gitignore
index 9dc547c9c..91530fe1c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -71,3 +71,4 @@ USER.md
 
 # local tooling
 .serena/
+package-lock.json
diff --git a/src/config/schema.ts b/src/config/schema.ts
index 1401b0574..f8aa4db40 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -555,7 +555,7 @@ const FIELD_HELP: Record<string, string> = {
   "plugins.load.paths": "Additional plugin files or directories to load.",
   "plugins.slots": "Select which plugins own exclusive slots (memory, etc.).",
   "plugins.slots.memory":
-    'Select the active memory plugin by id, or "none" to disable memory plugins.',
+    'Select the active memory plugin(s): a single id, an array of ids for stackable plugins, or "none" to disable.',
   "plugins.entries": "Per-plugin settings keyed by plugin id (enable/disable + config payloads).",
   "plugins.entries.*.enabled": "Overrides plugin enable/disable for this entry (restart required).",
   "plugins.entries.*.config": "Plugin-defined config payload (schema is provided by the plugin).",
diff --git a/src/config/types.plugins.ts b/src/config/types.plugins.ts
index dbe51f38e..c2518e892 100644
--- a/src/config/types.plugins.ts
+++ b/src/config/types.plugins.ts
@@ -4,8 +4,13 @@ export type PluginEntryConfig = {
 };
 
 export type PluginSlotsConfig = {
-  /** Select which plugin owns the memory slot ("none" disables memory plugins). */
-  memory?: string;
+  /**
+   * Select which plugin(s) own the memory slot.
+   * - Single string: "memory-lancedb" - one plugin active
+   * - Array: ["memory-core", "memory-lancedb"] - multiple plugins active (stackable)
+   * - "none": disables all memory plugins
+   */
+  memory?: string | string[];
 };
 
 export type PluginsLoadConfig = {
diff --git a/src/config/validation.ts b/src/config/validation.ts
index b9758b65a..563838fb1 100644
--- a/src/config/validation.ts
+++ b/src/config/validation.ts
@@ -199,11 +199,21 @@ export function validateConfigObjectWithPlugins(raw: unknown):
   }
 
   const memorySlot = normalizedPlugins.slots.memory;
+  // Validate memory slot - can be string or array of strings
   if (typeof memorySlot === "string" && memorySlot.trim() && !knownIds.has(memorySlot)) {
     issues.push({
       path: "plugins.slots.memory",
       message: `plugin not found: ${memorySlot}`,
     });
+  } else if (Array.isArray(memorySlot)) {
+    for (const slotId of memorySlot) {
+      if (typeof slotId === "string" && slotId.trim() && !knownIds.has(slotId)) {
+        issues.push({
+          path: "plugins.slots.memory",
+          message: `plugin not found: ${slotId}`,
+        });
+      }
+    }
   }
 
   const allowedChannels = new Set<string>(["defaults", ...CHANNEL_IDS]);
diff --git a/src/config/zod-schema.ts b/src/config/zod-schema.ts
index 961ba8ecb..fa50d8369 100644
--- a/src/config/zod-schema.ts
+++ b/src/config/zod-schema.ts
@@ -495,7 +495,7 @@ export const OpenClawSchema = z
           .optional(),
         slots: z
           .object({
-            memory: z.string().optional(),
+            memory: z.union([z.string(), z.array(z.string())]).optional(),
           })
           .strict()
           .optional(),
diff --git a/src/plugins/config-state.ts b/src/plugins/config-state.ts
index 9c424a23e..954a8d916 100644
--- a/src/plugins/config-state.ts
+++ b/src/plugins/config-state.ts
@@ -8,7 +8,7 @@ export type NormalizedPluginsConfig = {
   deny: string[];
   loadPaths: string[];
   slots: {
-    memory?: string | null;
+    memory?: string | string[] | null;
   };
   entries: Record<string, { enabled?: boolean; config?: unknown }>;
 };
@@ -20,7 +20,15 @@ const normalizeList = (value: unknown): string[] => {
   return value.map((entry) => (typeof entry === "string" ? entry.trim() : "")).filter(Boolean);
 };
 
-const normalizeSlotValue = (value: unknown): string | null | undefined => {
+const normalizeSlotValue = (value: unknown): string | string[] | null | undefined => {
+  // Handle array of plugin ids (stackable mode)
+  if (Array.isArray(value)) {
+    const normalized = value
+      .map((entry) => (typeof entry === "string" ? entry.trim() : ""))
+      .filter(Boolean);
+    return normalized.length > 0 ? normalized : undefined;
+  }
+  // Handle single string
   if (typeof value !== "string") return undefined;
   const trimmed = value.trim();
   if (!trimmed) return undefined;
@@ -144,7 +152,9 @@ export function resolveEnableState(
   if (config.allow.length > 0 && !config.allow.includes(id)) {
     return { enabled: false, reason: "not in allowlist" };
   }
-  if (config.slots.memory === id) {
+  // Check if plugin is selected in memory slot (handles both string and array)
+  const memorySlot = config.slots.memory;
+  if (memorySlot === id || (Array.isArray(memorySlot) && memorySlot.includes(id))) {
     return { enabled: true };
   }
   const entry = config.entries[id];
@@ -166,13 +176,24 @@ export function resolveEnableState(
 export function resolveMemorySlotDecision(params: {
   id: string;
   kind?: string;
-  slot: string | null | undefined;
+  slot: string | string[] | null | undefined;
   selectedId: string | null;
 }): { enabled: boolean; reason?: string; selected?: boolean } {
   if (params.kind !== "memory") return { enabled: true };
   if (params.slot === null) {
     return { enabled: false, reason: "memory slot disabled" };
   }
+  // Handle array of memory plugins (stackable mode)
+  if (Array.isArray(params.slot)) {
+    if (params.slot.includes(params.id)) {
+      return { enabled: true, selected: true };
+    }
+    return {
+      enabled: false,
+      reason: `memory slot set to [${params.slot.join(", ")}]`,
+    };
+  }
+  // Handle single string (exclusive mode - original behavior)
   if (typeof params.slot === "string") {
     if (params.slot === params.id) {
       return { enabled: true, selected: true };
diff --git a/src/plugins/slots.ts b/src/plugins/slots.ts
index 785bccbad..f8cbee749 100644
--- a/src/plugins/slots.ts
+++ b/src/plugins/slots.ts
@@ -52,9 +52,15 @@ export function applyExclusiveSlotSelection(params: {
   };
 
   const inferredPrevSlot = prevSlot ?? defaultSlotIdForKey(slotKey);
+  // Format slot value for display (handles both string and array)
+  const formatSlotValue = (v: string | string[] | null | undefined): string => {
+    if (v === null || v === undefined) return "none";
+    if (Array.isArray(v)) return `[${v.join(", ")}]`;
+    return v;
+  };
   if (inferredPrevSlot && inferredPrevSlot !== params.selectedId) {
     warnings.push(
-      `Exclusive slot "${slotKey}" switched from "${inferredPrevSlot}" to "${params.selectedId}".`,
+      `Exclusive slot "${slotKey}" switched from "${formatSlotValue(inferredPrevSlot)}" to "${params.selectedId}".`,
     );
   }