diff --git a/openclaw/index.ts b/openclaw/index.ts
index 4b4c890414..ac30db1000 100644
--- a/openclaw/index.ts
+++ b/openclaw/index.ts
@@ -25,7 +25,11 @@ import type {
   AddOptions,
   SearchOptions,
 } from "./types.ts";
-import { createProvider, providerToBackend } from "./providers.ts";
+import {
+  createProvider,
+  customCategoryMapToList,
+  providerToBackend,
+} from "./providers.ts";
 import { mem0ConfigSchema } from "./config.ts";
 import type { FileConfig } from "./config.ts";
 import { createPublicArtifactsProvider } from "./public-artifacts.ts";
@@ -273,7 +277,8 @@ const memoryPlugin = definePluginEntry({
       if (runId) opts.run_id = runId;
       // Pass customInstructions and customCategories to control what Mem0 extracts
       if (cfg.customInstructions) opts.custom_instructions = cfg.customInstructions;
-      if (cfg.customCategories) opts.custom_categories = cfg.customCategories;
+      const customCategories = customCategoryMapToList(cfg.customCategories);
+      if (customCategories) opts.custom_categories = customCategories;
       return opts;
     }
 
diff --git a/openclaw/providers.ts b/openclaw/providers.ts
index 6911adedc7..b345aa5024 100644
--- a/openclaw/providers.ts
+++ b/openclaw/providers.ts
@@ -13,6 +13,16 @@ import type {
   AddResult,
 } from "./types.ts";
 
+export function customCategoryMapToList(
+  categories?: Record<string, string>,
+): Array<Record<string, string>> | undefined {
+  if (!categories || typeof categories !== "object") return undefined;
+  const items = Object.entries(categories).map(([name, description]) => ({
+    [name]: description,
+  }));
+  return items.length ? items : undefined;
+}
+
 // ============================================================================
 // Result Normalizers
 // ============================================================================
diff --git a/openclaw/tests/providers.test.ts b/openclaw/tests/providers.test.ts
index 024bf3d91b..b48f5ad5b1 100644
--- a/openclaw/tests/providers.test.ts
+++ b/openclaw/tests/providers.test.ts
@@ -6,7 +6,11 @@
  */
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
-import { providerToBackend } from "../providers.ts";
+import {
+  createProvider,
+  customCategoryMapToList,
+  providerToBackend,
+} from "../providers.ts";
 
 // ---------------------------------------------------------------------------
 // Mock provider factory
@@ -37,6 +41,77 @@ beforeEach(() => {
   vi.resetAllMocks();
 });
 
+// ---------------------------------------------------------------------------
+// customCategoryMapToList
+// ---------------------------------------------------------------------------
+
+describe("customCategoryMapToList", () => {
+  it("converts category maps to the Mem0 SDK list shape", () => {
+    expect(
+      customCategoryMapToList({
+        preference: "User preferences",
+        work: "Work context",
+      }),
+    ).toEqual([
+      { preference: "User preferences" },
+      { work: "Work context" },
+    ]);
+  });
+
+  it("returns undefined for empty or missing category maps", () => {
+    expect(customCategoryMapToList()).toBeUndefined();
+    expect(customCategoryMapToList({})).toBeUndefined();
+  });
+});
+
+// ---------------------------------------------------------------------------
+// PlatformProvider
+// ---------------------------------------------------------------------------
+
+describe("PlatformProvider", () => {
+  it("passes custom_categories as a list to the Mem0 SDK", async () => {
+    let addOptions: Record<string, unknown> | undefined;
+
+    vi.doMock("mem0ai", () => ({
+      default: class MockMemoryClient {
+        async add(_messages: unknown, opts: Record<string, unknown>) {
+          addOptions = opts;
+          return { results: [] };
+        }
+      },
+    }));
+
+    const provider = createProvider(
+      {
+        mode: "platform",
+        apiKey: "test-key",
+        userId: "test-user",
+        autoCapture: true,
+        autoRecall: true,
+        customInstructions: "Store durable facts.",
+        customCategories: {},
+        searchThreshold: 0.1,
+        topK: 5,
+      },
+      { resolvePath: (p: string) => p } as any,
+    );
+
+    await provider.add([{ role: "user", content: "Remember this" }], {
+      user_id: "test-user",
+      custom_categories: customCategoryMapToList({
+        preference: "User preferences",
+      }),
+      source: "OPENCLAW",
+    });
+
+    expect(addOptions?.customCategories).toEqual([
+      { preference: "User preferences" },
+    ]);
+
+    vi.doUnmock("mem0ai");
+  });
+});
+
 // ---------------------------------------------------------------------------
 // search
 // ---------------------------------------------------------------------------
diff --git a/openclaw/types.ts b/openclaw/types.ts
index 5c7b1ac888..29d5523966 100644
--- a/openclaw/types.ts
+++ b/openclaw/types.ts
@@ -36,7 +36,7 @@ export interface AddOptions {
   user_id: string;
   run_id?: string;
   custom_instructions?: string;
-  custom_categories?: Record<string, string>;
+  custom_categories?: Array<Record<string, string>>;
   source?: string;
   // Agentic harness additions
   infer?: boolean;