diff --git a/apps/browser-extension/entrypoints/background.ts b/apps/browser-extension/entrypoints/background.ts
index e6dba3eb..f9f9c979 100644
--- a/apps/browser-extension/entrypoints/background.ts
+++ b/apps/browser-extension/entrypoints/background.ts
@@ -148,7 +148,17 @@ export default defineBackground(() => {
 		eventSource: string,
 	): Promise<{ success: boolean; data?: unknown; error?: string }> => {
 		try {
-			const responseData = await searchMemories(data)
+			let containerTag: string = CONTAINER_TAGS.DEFAULT_PROJECT
+			try {
+				const defaultProject = await getDefaultProject()
+				if (defaultProject?.containerTag) {
+					containerTag = defaultProject.containerTag
+				}
+			} catch (error) {
+				console.warn("Failed to get default project, using fallback:", error)
+			}
+
+			const responseData = await searchMemories(data, containerTag)
 			const response = responseData as {
 				results?: Array<{ memory?: string }>
 			}
diff --git a/apps/browser-extension/tsconfig.json b/apps/browser-extension/tsconfig.json
index 621fa129..781af494 100644
--- a/apps/browser-extension/tsconfig.json
+++ b/apps/browser-extension/tsconfig.json
@@ -4,5 +4,6 @@
 		"allowImportingTsExtensions": true,
 		"jsx": "react-jsx",
 		"types": ["chrome"]
-	}
+	},
+	"exclude": ["**/*.test.ts"]
 }
diff --git a/apps/browser-extension/utils/api.ts b/apps/browser-extension/utils/api.ts
index dd42d078..59cef3d7 100644
--- a/apps/browser-extension/utils/api.ts
+++ b/apps/browser-extension/utils/api.ts
@@ -3,6 +3,7 @@
  */
 import { API_ENDPOINTS } from "./constants"
 import { bearerToken, defaultProject, userData } from "./storage"
+import { buildSearchMemoriesBody } from "./search-request"
 import {
 	AuthenticationError,
 	type MemoryPayload,
@@ -145,14 +146,14 @@ export async function saveMemory(payload: MemoryPayload): Promise<unknown> {
 /**
  * Search memories using Supermemory API
  */
-export async function searchMemories(query: string): Promise<unknown> {
+export async function searchMemories(
+	query: string,
+	containerTag?: string,
+): Promise<unknown> {
 	try {
 		const response = await makeAuthenticatedRequest<unknown>("/v4/search", {
 			method: "POST",
-			body: JSON.stringify({
-				q: query,
-				include: { relatedMemories: true },
-			}),
+			body: JSON.stringify(buildSearchMemoriesBody(query, containerTag)),
 		})
 		return response
 	} catch (error) {
diff --git a/apps/browser-extension/utils/search-request.test.ts b/apps/browser-extension/utils/search-request.test.ts
new file mode 100644
index 00000000..228d0060
--- /dev/null
+++ b/apps/browser-extension/utils/search-request.test.ts
@@ -0,0 +1,19 @@
+import { describe, expect, it } from "bun:test"
+import { buildSearchMemoriesBody } from "./search-request"
+
+describe("buildSearchMemoriesBody", () => {
+	it("builds the default related-memory search body", () => {
+		expect(buildSearchMemoriesBody("deploy notes")).toEqual({
+			q: "deploy notes",
+			include: { relatedMemories: true },
+		})
+	})
+
+	it("includes the container tag when provided", () => {
+		expect(buildSearchMemoriesBody("deploy notes", "sm_project_docs")).toEqual({
+			q: "deploy notes",
+			include: { relatedMemories: true },
+			containerTag: "sm_project_docs",
+		})
+	})
+})
diff --git a/apps/browser-extension/utils/search-request.ts b/apps/browser-extension/utils/search-request.ts
new file mode 100644
index 00000000..95c547a1
--- /dev/null
+++ b/apps/browser-extension/utils/search-request.ts
@@ -0,0 +1,14 @@
+export function buildSearchMemoriesBody(
+	query: string,
+	containerTag?: string,
+): {
+	q: string
+	include: { relatedMemories: boolean }
+	containerTag?: string
+} {
+	return {
+		q: query,
+		include: { relatedMemories: true },
+		...(containerTag ? { containerTag } : {}),
+	}
+}