diff --git a/apps/mcp/src/shared/types.ts b/apps/mcp/src/shared/types.ts
index c46eb2d8..34affbf2 100644
--- a/apps/mcp/src/shared/types.ts
+++ b/apps/mcp/src/shared/types.ts
@@ -124,5 +124,5 @@ export type Props = {
 	containerTag?: string
 }
 
-// MCP resource URI for the widget bundle.
-export const SUPERMEMORY_RESOURCE_URI = "ui://supermemory/app.html"
+// Hosts cache MCP UI resources by URI, so bump this when shipping a new widget bundle.
+export const SUPERMEMORY_RESOURCE_URI = "ui://supermemory/app-v2.html"
diff --git a/apps/mcp/src/widget/hooks/useApp.ts b/apps/mcp/src/widget/hooks/useApp.ts
index 816b0987..e011dd91 100644
--- a/apps/mcp/src/widget/hooks/useApp.ts
+++ b/apps/mcp/src/widget/hooks/useApp.ts
@@ -47,16 +47,12 @@ export function useApp() {
 				}
 			},
 
-			/** Inject a user message into the conversation. Triggers a new agent turn. */
-			async sendMessage(content: string): Promise<ToolCallResult> {
+			/** Make widget state available to the model on a future turn. */
+			async updateModelContext(content: string): Promise<ToolCallResult> {
 				try {
-					const result = await app.sendMessage({
-						role: "user",
+					await app.updateModelContext({
 						content: [{ type: "text", text: content }],
 					})
-					if (result.isError) {
-						return { ok: false, error: "Host rejected the message" }
-					}
 					return { ok: true }
 				} catch (err) {
 					return { ok: false, error: String(err) }
diff --git a/apps/mcp/src/widget/views/Picker.tsx b/apps/mcp/src/widget/views/Picker.tsx
index f86b2941..a6a137d0 100644
--- a/apps/mcp/src/widget/views/Picker.tsx
+++ b/apps/mcp/src/widget/views/Picker.tsx
@@ -28,7 +28,7 @@ export function Picker({
 	onAdvance,
 	onError,
 }: Props) {
-	const { callTool, sendMessage } = useApp()
+	const { callTool, updateModelContext } = useApp()
 	const log = useLog()
 	const [pending, setPending] = useState<string | null>(null)
 	const [query, setQuery] = useState("")
@@ -56,13 +56,13 @@ export function Picker({
 			return
 		}
 		onAdvance(result.data)
-		const notification = await sendMessage(
-			`I selected "${containerTag}" as my active Supermemory workspace. Use this workspace for future Supermemory actions until I select another one.`,
+		const contextUpdate = await updateModelContext(
+			`Supermemory workspace selection changed. Active workspace: "${containerTag}". Use it for future Supermemory actions until another workspace is selected.`,
 		)
-		if (!notification.ok) {
+		if (!contextUpdate.ok) {
 			log(
 				"warning",
-				`[picker] agent notification failed: ${notification.error}`,
+				`[picker] model context update failed: ${contextUpdate.error}`,
 			)
 		}
 	}
diff --git a/apps/mcp/src/widget/views/Save.tsx b/apps/mcp/src/widget/views/Save.tsx
index 50e15813..83dd7211 100644
--- a/apps/mcp/src/widget/views/Save.tsx
+++ b/apps/mcp/src/widget/views/Save.tsx
@@ -27,7 +27,7 @@ export function Save({
 	onAdvance,
 	onError,
 }: Props) {
-	const { callTool, sendMessage } = useApp()
+	const { callTool, updateModelContext } = useApp()
 	const log = useLog()
 	const [content, setContent] = useState(prefill ?? "")
 	const [selectedTag, setSelectedTag] = useState<string | null>(
@@ -66,11 +66,14 @@ export function Save({
 		const memoryId =
 			result.data.view === "save-success" ? result.data.id : undefined
 		onAdvance(result.data)
-		const notification = await sendMessage(
-			`I used the Supermemory widget to save a memory to workspace "${selectedTag}"${memoryId ? ` (memory ID: ${memoryId})` : ""}. The memory is already saved; do not save it again.`,
+		const contextUpdate = await updateModelContext(
+			`Supermemory widget action completed. A memory was saved to workspace "${selectedTag}"${memoryId ? ` with memory ID "${memoryId}"` : ""}. It is already saved; do not save it again.`,
 		)
-		if (!notification.ok) {
-			log("warning", `[save] agent notification failed: ${notification.error}`)
+		if (!contextUpdate.ok) {
+			log(
+				"warning",
+				`[save] model context update failed: ${contextUpdate.error}`,
+			)
 		}
 	}
 
diff --git a/apps/mcp/src/widget/views/Upload.tsx b/apps/mcp/src/widget/views/Upload.tsx
index d05921fb..f20add32 100644
--- a/apps/mcp/src/widget/views/Upload.tsx
+++ b/apps/mcp/src/widget/views/Upload.tsx
@@ -30,7 +30,7 @@ function formatFileSize(bytes: number): string {
 const ACCEPT = ".txt,.pdf,.png,.jpg,.jpeg,.mp4"
 
 export function Upload({ activeTag, writableTags, onAdvance, onError }: Props) {
-	const { callTool, sendMessage } = useApp()
+	const { callTool, updateModelContext } = useApp()
 	const log = useLog()
 	const [file, setFile] = useState<File | null>(null)
 	const [selectedTag, setSelectedTag] = useState<string | null>(
@@ -65,13 +65,13 @@ export function Upload({ activeTag, writableTags, onAdvance, onError }: Props) {
 			const documentId =
 				result.data.view === "upload-success" ? result.data.id : undefined
 			onAdvance(result.data)
-			const notification = await sendMessage(
-				`I used the Supermemory widget to upload "${file.name}" to workspace "${selectedTag}"${documentId ? ` (document ID: ${documentId})` : ""}. The file is already uploaded; do not upload it again.`,
+			const contextUpdate = await updateModelContext(
+				`Supermemory widget action completed. "${file.name}" was uploaded to workspace "${selectedTag}"${documentId ? ` with document ID "${documentId}"` : ""}. It is already uploaded; do not upload it again.`,
 			)
-			if (!notification.ok) {
+			if (!contextUpdate.ok) {
 				log(
 					"warning",
-					`[upload] agent notification failed: ${notification.error}`,
+					`[upload] model context update failed: ${contextUpdate.error}`,
 				)
 			}
 		} catch (err) {