diff --git a/packages/types/src/__tests__/global-settings.test.ts b/packages/types/src/__tests__/global-settings.test.ts
index f2b2e7e8e5..b6b01cccf0 100644
--- a/packages/types/src/__tests__/global-settings.test.ts
+++ b/packages/types/src/__tests__/global-settings.test.ts
@@ -39,6 +39,49 @@ describe("alwaysDenyUnapprovedCommands global setting", () => {
 	})
 })
 
+describe("viewStates global setting", () => {
+	it("parses a valid per-view record", () => {
+		const parsed = globalSettingsSchema.parse({
+			viewStates: {
+				"stable-view-1": { mode: "code", currentApiConfigName: "profile-a", updatedAt: 1730000000000 },
+				"stable-view-2": {},
+			},
+		})
+		expect(parsed.viewStates?.["stable-view-1"]).toEqual({
+			mode: "code",
+			currentApiConfigName: "profile-a",
+			updatedAt: 1730000000000,
+		})
+		expect(parsed.viewStates?.["stable-view-2"]).toEqual({})
+		expect(GLOBAL_SETTINGS_KEYS).toContain("viewStates")
+	})
+
+	it("parses an entry that carries the host-minted claim token", () => {
+		// The claim binds the entry to the webview that wrote it; a legacy entry without one
+		// still parses, because refusing it is setViewStateId's job, not the schema's.
+		const parsed = globalSettingsSchema.parse({
+			viewStates: {
+				"stable-view-1": { mode: "code", updatedAt: 1730000000000, claimToken: "7f9c-host-minted" },
+				"stable-view-2": { mode: "code" },
+			},
+		})
+		expect(parsed.viewStates?.["stable-view-1"]?.claimToken).toBe("7f9c-host-minted")
+		expect(parsed.viewStates?.["stable-view-2"]).toEqual({ mode: "code" })
+	})
+
+	it("rejects invalid field values inside a view entry", () => {
+		expect(() => globalSettingsSchema.parse({ viewStates: { v: { mode: 42 } } })).toThrow()
+		expect(() => globalSettingsSchema.parse({ viewStates: { v: { currentApiConfigName: 42 } } })).toThrow()
+		expect(() => globalSettingsSchema.parse({ viewStates: { v: { updatedAt: "soon" } } })).toThrow()
+		expect(() => globalSettingsSchema.parse({ viewStates: { v: { claimToken: 42 } } })).toThrow()
+	})
+
+	it("rejects non-object viewStates values", () => {
+		expect(() => globalSettingsSchema.parse({ viewStates: "not-a-record" })).toThrow()
+		expect(() => globalSettingsSchema.parse({ viewStates: { v: "not-an-entry" } })).toThrow()
+	})
+})
+
 describe("collapseCommandOutputByDefault global setting", () => {
 	it.each([true, false, undefined])("round-trips %s through the export/import schema", (value) => {
 		const settings = globalSettingsSchema.parse({ collapseCommandOutputByDefault: value })
diff --git a/packages/types/src/__tests__/index.test.ts b/packages/types/src/__tests__/index.test.ts
index 15441d48fd..b4cee22f8c 100644
--- a/packages/types/src/__tests__/index.test.ts
+++ b/packages/types/src/__tests__/index.test.ts
@@ -3,6 +3,10 @@
 import { GLOBAL_STATE_KEYS } from "../index.js"
 
 describe("GLOBAL_STATE_KEYS", () => {
+	it("should contain registered durable per-view state", () => {
+		expect(GLOBAL_STATE_KEYS).toContain("viewStates")
+	})
+
 	it("should contain provider settings keys", () => {
 		expect(GLOBAL_STATE_KEYS).toContain("autoApprovalEnabled")
 	})
@@ -13,6 +17,7 @@ describe("GLOBAL_STATE_KEYS", () => {
 
 	it("should not contain secret state keys", () => {
 		expect(GLOBAL_STATE_KEYS).not.toContain("openRouterApiKey")
+		expect(GLOBAL_STATE_KEYS).not.toContain("apiKey")
 	})
 
 	it("should contain OpenAI Compatible base URL setting", () => {
diff --git a/packages/types/src/global-settings.ts b/packages/types/src/global-settings.ts
index f5757a51c7..38d4292adb 100644
--- a/packages/types/src/global-settings.ts
+++ b/packages/types/src/global-settings.ts
@@ -114,6 +114,17 @@ export const MAX_CHECKPOINT_TIMEOUT_SECONDS = 60
  */
 export const DEFAULT_CHECKPOINT_TIMEOUT_SECONDS = 15
 
+/**
+ * Persisted non-secret selections for a stable webview instance.
+ */
+export const viewStateSchema = z.object({
+	mode: z.string().optional(),
+	currentApiConfigName: z.string().optional(),
+	updatedAt: z.number().optional(),
+	/** Host-minted token binding this entry to the webview that wrote it. */
+	claimToken: z.string().optional(),
+})
+
 /**
  * GlobalSettings
  */
@@ -122,6 +133,7 @@ export const globalSettingsSchema = z.object({
 	currentApiConfigName: z.string().optional(),
 	listApiConfigMeta: z.array(providerSettingsEntrySchema).optional(),
 	pinnedApiConfigs: z.record(z.string(), z.boolean()).optional(),
+	viewStates: z.record(z.string(), viewStateSchema).optional(),
 
 	lastShownAnnouncementId: z.string().optional(),
 	customInstructions: z.string().optional(),
diff --git a/packages/types/src/vscode-extension-host.ts b/packages/types/src/vscode-extension-host.ts
index 8a006c0639..52ef624e56 100644
--- a/packages/types/src/vscode-extension-host.ts
+++ b/packages/types/src/vscode-extension-host.ts
@@ -113,6 +113,7 @@ export interface ExtensionMessage {
 		| "rooHistoryImportProgress"
 		| "themeFixtureProbeRequest"
 		| "diagnosticsRequest"
+		| "viewStateClaim"
 	text?: string
 	/** For fileContent: { path, content, error? } */
 	fileContent?: { path: string; content: string | null; error?: string }
@@ -171,6 +172,13 @@ export interface ExtensionMessage {
 	// eslint-disable-next-line @typescript-eslint/no-explicit-any
 	values?: Record<string, any>
 	requestId?: string
+	/**
+	 * For `viewStateClaim`: the durable `viewStates` key the delivered claim governs. The
+	 * message is only ever sent to the webview that key belongs to.
+	 */
+	viewStateId?: string
+	/** For `viewStateClaim`: the host-minted token the webview stores and echoes on launch. */
+	viewStateClaim?: string
 	themeFixture?: WebviewThemeFixture
 	diagnostics?: WebviewDiagnosticsSnapshot
 	promptText?: string
@@ -712,6 +720,9 @@ export interface WebviewMessage {
 		| "themeFixtureProbeResponse"
 		| "diagnosticsResponse"
 	text?: string
+	viewStateId?: string
+	/** For `webviewDidLaunch`: the claim delivered for `viewStateId`, enforced by setViewStateId. */
+	viewStateClaim?: string
 	taskId?: string
 	editedMessageContent?: string
 	tab?: "settings" | "history" | "mcp" | "modes" | "chat" | "marketplace" | "cloud"
diff --git a/src/core/config/ContextProxy.ts b/src/core/config/ContextProxy.ts
index e53f60fb83..fb26bf9507 100644
--- a/src/core/config/ContextProxy.ts
+++ b/src/core/config/ContextProxy.ts
@@ -67,8 +67,21 @@ const globalSettingsExportSchema = globalSettingsSchema.omit({
 	taskHistory: true,
 	listApiConfigMeta: true,
 	currentApiConfigName: true,
+	// Host-minted claim tokens and per-view selections are not user-settings: exporting
+	// them would let a settings file be replayed as another view's identity.
+	viewStates: true,
 })
 
+/**
+ * Global settings a settings file may not carry in either direction. Per-view selections and the
+ * claim token that binds them are minted and held by the extension host, so a file that could
+ * set them would be replayable as another view's identity. The export side omits the key above;
+ * the import side consults this list in `sanitizeGlobalSettings`.
+ */
+const NON_PORTABLE_SETTINGS_KEYS: readonly string[] = ["viewStates"]
+
+export const isNonPortableSettingsKey = (key: string): boolean => NON_PORTABLE_SETTINGS_KEYS.includes(key)
+
 export class ContextProxy {
 	private readonly originalContext: vscode.ExtensionContext
 
@@ -666,7 +679,16 @@ export class ContextProxy {
 	 * rollback, must provide it themselves.
 	 */
 	public async setValues(values: RooCodeSettings) {
-		const entries = Object.entries(values) as [RooCodeSettingsKey, unknown][]
+		// viewStates is host-owned: per-view selections and the claim token that binds them are
+		// minted by the extension host, so no configuration path may carry them. Every caller of
+		// this setter takes input that did not originate inside the host - a posted updateSettings,
+		// a newTask taskConfiguration, the external API, an imported settings file - so the filter
+		// lives here rather than at whichever caller a reviewer happened to point at. The host's
+		// own view-state methods write through setValue("viewStates", ...), which stays open.
+		const entries = Object.entries(values).filter(([key]) => !isNonPortableSettingsKey(key)) as [
+			RooCodeSettingsKey,
+			unknown,
+		][]
 		const results = await Promise.allSettled(entries.map(([key, value]) => this.setValue(key, value)))
 
 		const committed: string[] = []
diff --git a/src/core/config/ProviderSettingsManager.ts b/src/core/config/ProviderSettingsManager.ts
index 01695d7994..07a5fc3d21 100644
--- a/src/core/config/ProviderSettingsManager.ts
+++ b/src/core/config/ProviderSettingsManager.ts
@@ -55,6 +55,14 @@ export const providerProfilesSchema = z.object({
 
 export type ProviderProfiles = z.infer<typeof providerProfilesSchema>
 
+/** Already-deleted profile: callers branch on this type instead of matching message text. */
+export class ProviderSettingsNotFoundError extends Error {
+	constructor(message: string) {
+		super(message)
+		this.name = "ProviderSettingsNotFoundError"
+	}
+}
+
 export class ProviderSettingsManager {
 	private static readonly SCOPE_PREFIX = "roo_cline_config_"
 	private readonly defaultConfigId = this.generateId()
@@ -511,7 +519,7 @@ export class ProviderSettingsManager {
 				const providerProfiles = await this.load()
 
 				if (!providerProfiles.apiConfigs[name]) {
-					throw new Error(`Config '${name}' not found`)
+					throw new ProviderSettingsNotFoundError(`Config '${name}' not found`)
 				}
 
 				if (Object.keys(providerProfiles.apiConfigs).length === 1) {
@@ -522,6 +530,11 @@ export class ProviderSettingsManager {
 				await this.store(providerProfiles)
 			})
 		} catch (error) {
+			// A missing config is a caller-meaningful signal, not a failure: rethrow it
+			// unwrapped so callers can branch on the type instead of message text.
+			if (error instanceof ProviderSettingsNotFoundError) {
+				throw error
+			}
 			throw new Error(`Failed to delete config: ${error}`)
 		}
 	}
diff --git a/src/core/config/__tests__/ContextProxy.spec.ts b/src/core/config/__tests__/ContextProxy.spec.ts
index 5d78e16351..a4232c3a05 100644
--- a/src/core/config/__tests__/ContextProxy.spec.ts
+++ b/src/core/config/__tests__/ContextProxy.spec.ts
@@ -837,6 +837,25 @@ describe("ContextProxy", () => {
 		})
 	})
 
+	describe("export()", () => {
+		it("omits host-owned viewStates from a settings export", async () => {
+			await proxy.setValue("viewStates", {
+				"export-view": { claimToken: "export-claim-token", mode: "architect" },
+			})
+			// A portable global setting the export schema keeps: without it the test would pass on an
+			// empty export, because every remaining check only asserts absence.
+			await proxy.setValue("customInstructions", "retain these instructions")
+			// The cache carries the key; only the export must not.
+			expect(Object.keys(proxy.getValues())).toContain("viewStates")
+			const exported = await proxy.export()
+			expect(exported?.customInstructions).toBe("retain these instructions")
+			expect(exported && Object.keys(exported)).not.toContain("viewStates")
+			expect(exported && "viewStates" in exported).toBe(false)
+			// The value must not escape under another name either: the claim token is host state.
+			expect(JSON.stringify(exported)).not.toContain("export-claim-token")
+		})
+	})
+
 	describe("resetAllState", () => {
 		it("should clear all in-memory caches", async () => {
 			// Setup initial state in caches
diff --git a/src/core/config/__tests__/ProviderSettingsManager.spec.ts b/src/core/config/__tests__/ProviderSettingsManager.spec.ts
index a1fc9ac7de..3b93b7cd22 100644
--- a/src/core/config/__tests__/ProviderSettingsManager.spec.ts
+++ b/src/core/config/__tests__/ProviderSettingsManager.spec.ts
@@ -12,7 +12,7 @@ import {
 import { clearAllMocks } from "../../../test-utils/reset"
 import { makeExtensionContext } from "../../../test-utils/vscode"
 
-import { ProviderSettingsManager, ProviderProfiles } from "../ProviderSettingsManager"
+import { ProviderSettingsManager, ProviderSettingsNotFoundError, ProviderProfiles } from "../ProviderSettingsManager"
 
 // `export()` builds an API handler per profile to read model capabilities. Mock
 // buildApiHandler with the real @roo-code/types model definitions so the token-field
@@ -973,6 +973,11 @@ describe("ProviderSettingsManager", () => {
 				}),
 			)
 
+			// The typed not-found signal is the contract callers branch on: a profile
+			// name containing "not found" must not be matchable via message text.
+			await expect(providerSettingsManager.deleteConfig("nonexistent")).rejects.toBeInstanceOf(
+				ProviderSettingsNotFoundError,
+			)
 			await expect(providerSettingsManager.deleteConfig("nonexistent")).rejects.toThrow(
 				"Config 'nonexistent' not found",
 			)
diff --git a/src/core/config/__tests__/importExport.spec.ts b/src/core/config/__tests__/importExport.spec.ts
index 6c66655325..4ea47d2298 100644
--- a/src/core/config/__tests__/importExport.spec.ts
+++ b/src/core/config/__tests__/importExport.spec.ts
@@ -251,6 +251,55 @@ describe("importExport", () => {
 		})
 	})
 
+	describe("host-owned view state on import", () => {
+		const settingsWithImportedViewStates = JSON.stringify({
+			providerProfiles: {
+				currentApiConfigName: "test",
+				apiConfigs: {
+					test: { apiProvider: providerIdentifiers.openai, apiKey: "test-key", id: "test-id" },
+				},
+			},
+			globalSettings: {
+				customInstructions: "keep me",
+				viewStates: { "view-1": { mode: "architect", claimToken: "planted-claim" } },
+			},
+		})
+
+		beforeEach(() => {
+			;(fs.readFile as Mock).mockResolvedValue(settingsWithImportedViewStates)
+			mockProviderSettingsManager.export.mockResolvedValue({
+				currentApiConfigName: "default",
+				apiConfigs: { default: { apiProvider: providerIdentifiers.anthropic, id: "default-id" } },
+			})
+			mockProviderSettingsManager.import.mockResolvedValue(undefined)
+			mockProviderSettingsManager.listConfig.mockResolvedValue([])
+			mockContextProxy.setValues.mockResolvedValue(undefined)
+			mockContextProxy.setValue.mockResolvedValue(undefined)
+			mockContextProxy.setProviderSettings.mockResolvedValue(undefined)
+		})
+
+		it("drops viewStates so an imported file cannot plant another view's claim", async () => {
+			const result = await importSettingsFromPath("/mock/path/settings.json", {
+				providerSettingsManager: mockProviderSettingsManager,
+				contextProxy: mockContextProxy,
+				customModesManager: mockCustomModesManager,
+			})
+
+			expect(result).toMatchObject({ success: true })
+
+			// A claim token is host-minted: a file that could carry an entry could replay it as that
+			// view's identity, so the key is dropped before anything is written.
+			expect(mockContextProxy.setValues).toHaveBeenCalledTimes(1)
+			const [appliedSettings] = (mockContextProxy.setValues as Mock).mock.calls[0]
+			expect(appliedSettings).not.toHaveProperty("viewStates")
+			expect(appliedSettings).toMatchObject({ customInstructions: "keep me" })
+			const warnings = (result as { warnings?: string[] }).warnings ?? []
+			expect(warnings).toHaveLength(1)
+			expect(warnings[0]).toContain('globalSettings.viewStates" was skipped')
+			expect(warnings[0]).toContain("not portable")
+		})
+	})
+
 	describe("importSettings", () => {
 		it("should return success: false when user cancels file selection", async () => {
 			;(vscode.window.showOpenDialog as Mock).mockResolvedValue(undefined)
diff --git a/src/core/config/importExport.ts b/src/core/config/importExport.ts
index 9882039ad3..99f3ef6f6c 100644
--- a/src/core/config/importExport.ts
+++ b/src/core/config/importExport.ts
@@ -17,7 +17,7 @@ import {
 import { TelemetryService } from "@roo-code/telemetry"
 
 import { ProviderSettingsManager, providerProfilesSchema } from "./ProviderSettingsManager"
-import { ContextProxy } from "./ContextProxy"
+import { ContextProxy, isNonPortableSettingsKey } from "./ContextProxy"
 import { CustomModesManager } from "./CustomModesManager"
 import { downgradeLegacyRooConfig, ROUTER_REMOVAL_IMPORT_WARNING } from "./routerRemoval"
 import { resolveDefaultSaveUri, saveLastExportPath } from "../../utils/export"
@@ -105,6 +105,11 @@ function sanitizeGlobalSettings(rawGlobalSettings: unknown): {
 			continue
 		}
 
+		if (isNonPortableSettingsKey(key)) {
+			warnings.push(`Setting "${path}" was skipped: host-owned view state is not portable.`)
+			continue
+		}
+
 		let valueToValidate = rawValue
 
 		if (key === "imageGenerationProvider" && rawValue === retiredProviderIdentifiers.roo) {