feat: add code diff display mode preference (#25027)

coderd/apidoc/docs.go

@@ -14922,6 +14922,19 @@ const docTemplate = `{
                 }
             }
         },
+        "codersdk.AgentDisplayMode": {
+            "type": "string",
+            "enum": [
+                "auto",
+                "always_expanded",
+                "always_collapsed"
+            ],
+            "x-enum-varnames": [
+                "AgentDisplayModeAuto",
+                "AgentDisplayModeAlwaysExpanded",
+                "AgentDisplayModeAlwaysCollapsed"
+            ]
+        },
         "codersdk.AgentScriptTiming": {
             "type": "object",
             "properties": {
@@ -23385,6 +23398,9 @@ const docTemplate = `{
         "codersdk.UpdateUserPreferenceSettingsRequest": {
             "type": "object",
             "properties": {
+                "code_diff_display_mode": {
+                    "$ref": "#/definitions/codersdk.AgentDisplayMode"
+                },
                 "task_notification_alert_dismissed": {
                     "type": "boolean"
                 },
@@ -23855,6 +23871,9 @@ const docTemplate = `{
         "codersdk.UserPreferenceSettings": {
             "type": "object",
             "properties": {
+                "code_diff_display_mode": {
+                    "$ref": "#/definitions/codersdk.AgentDisplayMode"
+                },
                 "task_notification_alert_dismissed": {
                     "type": "boolean"
                 },

coderd/apidoc/swagger.json

@@ -13388,6 +13388,15 @@
 				}
 			}
 		},
+		"codersdk.AgentDisplayMode": {
+			"type": "string",
+			"enum": ["auto", "always_expanded", "always_collapsed"],
+			"x-enum-varnames": [
+				"AgentDisplayModeAuto",
+				"AgentDisplayModeAlwaysExpanded",
+				"AgentDisplayModeAlwaysCollapsed"
+			]
+		},
 		"codersdk.AgentScriptTiming": {
 			"type": "object",
 			"properties": {
@@ -21529,6 +21538,9 @@
 		"codersdk.UpdateUserPreferenceSettingsRequest": {
 			"type": "object",
 			"properties": {
+				"code_diff_display_mode": {
+					"$ref": "#/definitions/codersdk.AgentDisplayMode"
+				},
 				"task_notification_alert_dismissed": {
 					"type": "boolean"
 				},
@@ -21970,6 +21982,9 @@
 		"codersdk.UserPreferenceSettings": {
 			"type": "object",
 			"properties": {
+				"code_diff_display_mode": {
+					"$ref": "#/definitions/codersdk.AgentDisplayMode"
+				},
 				"task_notification_alert_dismissed": {
 					"type": "boolean"
 				},

coderd/database/dbauthz/dbauthz.go

@@ -4408,6 +4408,17 @@ func (q *querier) GetUserChatSpendInPeriod(ctx context.Context, arg database.Get
 	return q.db.GetUserChatSpendInPeriod(ctx, arg)
 }
 
+func (q *querier) GetUserCodeDiffDisplayMode(ctx context.Context, userID uuid.UUID) (string, error) {
+	user, err := q.db.GetUserByID(ctx, userID)
+	if err != nil {
+		return "", err
+	}
+	if err := q.authorizeContext(ctx, policy.ActionReadPersonal, user); err != nil {
+		return "", err
+	}
+	return q.db.GetUserCodeDiffDisplayMode(ctx, userID)
+}
+
 func (q *querier) GetUserCount(ctx context.Context, includeSystem bool) (int64, error) {
 	if err := q.authorizeContext(ctx, policy.ActionRead, rbac.ResourceSystem); err != nil {
 		return 0, err
@@ -7024,6 +7035,17 @@ func (q *querier) UpdateUserChatProviderKey(ctx context.Context, arg database.Up
 	return q.db.UpdateUserChatProviderKey(ctx, arg)
 }
 
+func (q *querier) UpdateUserCodeDiffDisplayMode(ctx context.Context, arg database.UpdateUserCodeDiffDisplayModeParams) (string, error) {
+	user, err := q.db.GetUserByID(ctx, arg.UserID)
+	if err != nil {
+		return "", err
+	}
+	if err := q.authorizeContext(ctx, policy.ActionUpdatePersonal, user); err != nil {
+		return "", err
+	}
+	return q.db.UpdateUserCodeDiffDisplayMode(ctx, arg)
+}
+
 func (q *querier) UpdateUserDeletedByID(ctx context.Context, id uuid.UUID) error {
 	return deleteQ(q.log, q.auth, q.db.GetUserByID, q.db.UpdateUserDeletedByID)(ctx, id)
 }

coderd/database/dbauthz/dbauthz_test.go

@@ -2829,6 +2829,19 @@ func (s *MethodTestSuite) TestUser() {
 		dbm.EXPECT().UpdateUserThinkingDisplayMode(gomock.Any(), arg).Return("always_expanded", nil).AnyTimes()
 		check.Args(arg).Asserts(u, policy.ActionUpdatePersonal).Returns("always_expanded")
 	}))
+	s.Run("GetUserCodeDiffDisplayMode", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
+		u := testutil.Fake(s.T(), faker, database.User{})
+		dbm.EXPECT().GetUserByID(gomock.Any(), u.ID).Return(u, nil).AnyTimes()
+		dbm.EXPECT().GetUserCodeDiffDisplayMode(gomock.Any(), u.ID).Return("auto", nil).AnyTimes()
+		check.Args(u.ID).Asserts(u, policy.ActionReadPersonal).Returns("auto")
+	}))
+	s.Run("UpdateUserCodeDiffDisplayMode", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
+		u := testutil.Fake(s.T(), faker, database.User{})
+		arg := database.UpdateUserCodeDiffDisplayModeParams{UserID: u.ID, CodeDiffDisplayMode: "always_collapsed"}
+		dbm.EXPECT().GetUserByID(gomock.Any(), u.ID).Return(u, nil).AnyTimes()
+		dbm.EXPECT().UpdateUserCodeDiffDisplayMode(gomock.Any(), arg).Return("always_collapsed", nil).AnyTimes()
+		check.Args(arg).Asserts(u, policy.ActionUpdatePersonal).Returns("always_collapsed")
+	}))
 	s.Run("ListUserChatCompactionThresholds", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
 		u := testutil.Fake(s.T(), faker, database.User{})
 		uc := database.UserConfig{UserID: u.ID, Key: codersdk.ChatCompactionThresholdKeyPrefix + "00000000-0000-0000-0000-000000000001", Value: "75"}

coderd/database/dbmetrics/querymetrics.go

@@ -2848,6 +2848,14 @@ func (m queryMetricsStore) GetUserChatSpendInPeriod(ctx context.Context, arg dat
 	return r0, r1
 }
 
+func (m queryMetricsStore) GetUserCodeDiffDisplayMode(ctx context.Context, userID uuid.UUID) (string, error) {
+	start := time.Now()
+	r0, r1 := m.s.GetUserCodeDiffDisplayMode(ctx, userID)
+	m.queryLatencies.WithLabelValues("GetUserCodeDiffDisplayMode").Observe(time.Since(start).Seconds())
+	m.queryCounts.WithLabelValues(httpmw.ExtractHTTPRoute(ctx), httpmw.ExtractHTTPMethod(ctx), "GetUserCodeDiffDisplayMode").Inc()
+	return r0, r1
+}
+
 func (m queryMetricsStore) GetUserCount(ctx context.Context, includeSystem bool) (int64, error) {
 	start := time.Now()
 	r0, r1 := m.s.GetUserCount(ctx, includeSystem)
@@ -5008,6 +5016,14 @@ func (m queryMetricsStore) UpdateUserChatProviderKey(ctx context.Context, arg da
 	return r0, r1
 }
 
+func (m queryMetricsStore) UpdateUserCodeDiffDisplayMode(ctx context.Context, arg database.UpdateUserCodeDiffDisplayModeParams) (string, error) {
+	start := time.Now()
+	r0, r1 := m.s.UpdateUserCodeDiffDisplayMode(ctx, arg)
+	m.queryLatencies.WithLabelValues("UpdateUserCodeDiffDisplayMode").Observe(time.Since(start).Seconds())
+	m.queryCounts.WithLabelValues(httpmw.ExtractHTTPRoute(ctx), httpmw.ExtractHTTPMethod(ctx), "UpdateUserCodeDiffDisplayMode").Inc()
+	return r0, r1
+}
+
 func (m queryMetricsStore) UpdateUserDeletedByID(ctx context.Context, id uuid.UUID) error {
 	start := time.Now()
 	r0 := m.s.UpdateUserDeletedByID(ctx, id)

coderd/database/dbmock/dbmock.go

@@ -5327,6 +5327,21 @@ func (mr *MockStoreMockRecorder) GetUserChatSpendInPeriod(ctx, arg any) *gomock.
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetUserChatSpendInPeriod", reflect.TypeOf((*MockStore)(nil).GetUserChatSpendInPeriod), ctx, arg)
 }
 
+// GetUserCodeDiffDisplayMode mocks base method.
+func (m *MockStore) GetUserCodeDiffDisplayMode(ctx context.Context, userID uuid.UUID) (string, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetUserCodeDiffDisplayMode", ctx, userID)
+	ret0, _ := ret[0].(string)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// GetUserCodeDiffDisplayMode indicates an expected call of GetUserCodeDiffDisplayMode.
+func (mr *MockStoreMockRecorder) GetUserCodeDiffDisplayMode(ctx, userID any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetUserCodeDiffDisplayMode", reflect.TypeOf((*MockStore)(nil).GetUserCodeDiffDisplayMode), ctx, userID)
+}
+
 // GetUserCount mocks base method.
 func (m *MockStore) GetUserCount(ctx context.Context, includeSystem bool) (int64, error) {
 	m.ctrl.T.Helper()
@@ -9441,6 +9456,21 @@ func (mr *MockStoreMockRecorder) UpdateUserChatProviderKey(ctx, arg any) *gomock
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateUserChatProviderKey", reflect.TypeOf((*MockStore)(nil).UpdateUserChatProviderKey), ctx, arg)
 }
 
+// UpdateUserCodeDiffDisplayMode mocks base method.
+func (m *MockStore) UpdateUserCodeDiffDisplayMode(ctx context.Context, arg database.UpdateUserCodeDiffDisplayModeParams) (string, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "UpdateUserCodeDiffDisplayMode", ctx, arg)
+	ret0, _ := ret[0].(string)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// UpdateUserCodeDiffDisplayMode indicates an expected call of UpdateUserCodeDiffDisplayMode.
+func (mr *MockStoreMockRecorder) UpdateUserCodeDiffDisplayMode(ctx, arg any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateUserCodeDiffDisplayMode", reflect.TypeOf((*MockStore)(nil).UpdateUserCodeDiffDisplayMode), ctx, arg)
+}
+
 // UpdateUserDeletedByID mocks base method.
 func (m *MockStore) UpdateUserDeletedByID(ctx context.Context, id uuid.UUID) error {
 	m.ctrl.T.Helper()

coderd/database/querier.go

@@ -709,6 +709,7 @@ type sqlcQuerier interface {
 	// returned (global behavior). Otherwise only spend within the
 	// specified organization is included.
 	GetUserChatSpendInPeriod(ctx context.Context, arg GetUserChatSpendInPeriodParams) (int64, error)
+	GetUserCodeDiffDisplayMode(ctx context.Context, userID uuid.UUID) (string, error)
 	GetUserCount(ctx context.Context, includeSystem bool) (int64, error)
 	// Returns the minimum (most restrictive) group limit for a user.
 	// Returns -1 if no group limits match the specified scope.
@@ -1193,6 +1194,7 @@ type sqlcQuerier interface {
 	UpdateUserChatCompactionThreshold(ctx context.Context, arg UpdateUserChatCompactionThresholdParams) (UserConfig, error)
 	UpdateUserChatCustomPrompt(ctx context.Context, arg UpdateUserChatCustomPromptParams) (UserConfig, error)
 	UpdateUserChatProviderKey(ctx context.Context, arg UpdateUserChatProviderKeyParams) (UserChatProviderKey, error)
+	UpdateUserCodeDiffDisplayMode(ctx context.Context, arg UpdateUserCodeDiffDisplayModeParams) (string, error)
 	UpdateUserDeletedByID(ctx context.Context, id uuid.UUID) error
 	UpdateUserGithubComUserID(ctx context.Context, arg UpdateUserGithubComUserIDParams) error
 	UpdateUserHashedOneTimePasscode(ctx context.Context, arg UpdateUserHashedOneTimePasscodeParams) error

coderd/database/queries.sql.go

@@ -25703,6 +25703,23 @@ func (q *sqlQuerier) GetUserChatPersonalModelOverride(ctx context.Context, arg G
 	return personal_model_override, err
 }
 
+const getUserCodeDiffDisplayMode = `-- name: GetUserCodeDiffDisplayMode :one
+SELECT
+	value AS code_diff_display_mode
+FROM
+	user_configs
+WHERE
+	user_id = $1
+	AND key = 'preference_code_diff_display_mode'
+`
+
+func (q *sqlQuerier) GetUserCodeDiffDisplayMode(ctx context.Context, userID uuid.UUID) (string, error) {
+	row := q.db.QueryRowContext(ctx, getUserCodeDiffDisplayMode, userID)
+	var code_diff_display_mode string
+	err := row.Scan(&code_diff_display_mode)
+	return code_diff_display_mode, err
+}
+
 const getUserCount = `-- name: GetUserCount :one
 SELECT
 	COUNT(*)
@@ -26301,6 +26318,33 @@ func (q *sqlQuerier) UpdateUserChatCustomPrompt(ctx context.Context, arg UpdateU
 	return i, err
 }
 
+const updateUserCodeDiffDisplayMode = `-- name: UpdateUserCodeDiffDisplayMode :one
+INSERT INTO
+	user_configs (user_id, key, value)
+VALUES
+	($1, 'preference_code_diff_display_mode', $2::text)
+ON CONFLICT
+	ON CONSTRAINT user_configs_pkey
+DO UPDATE
+SET
+	value = $2
+WHERE user_configs.user_id = $1
+	AND user_configs.key = 'preference_code_diff_display_mode'
+RETURNING value AS code_diff_display_mode
+`
+
+type UpdateUserCodeDiffDisplayModeParams struct {
+	UserID              uuid.UUID `db:"user_id" json:"user_id"`
+	CodeDiffDisplayMode string    `db:"code_diff_display_mode" json:"code_diff_display_mode"`
+}
+
+func (q *sqlQuerier) UpdateUserCodeDiffDisplayMode(ctx context.Context, arg UpdateUserCodeDiffDisplayModeParams) (string, error) {
+	row := q.db.QueryRowContext(ctx, updateUserCodeDiffDisplayMode, arg.UserID, arg.CodeDiffDisplayMode)
+	var code_diff_display_mode string
+	err := row.Scan(&code_diff_display_mode)
+	return code_diff_display_mode, err
+}
+
 const updateUserDeletedByID = `-- name: UpdateUserDeletedByID :exec
 UPDATE
 	users

coderd/database/queries/users.sql

@@ -303,6 +303,30 @@ WHERE user_configs.user_id = @user_id
 	AND user_configs.key = 'preference_thinking_display_mode'
 RETURNING value AS thinking_display_mode;
 
+
+-- name: GetUserCodeDiffDisplayMode :one
+SELECT
+	value AS code_diff_display_mode
+FROM
+	user_configs
+WHERE
+	user_id = @user_id
+	AND key = 'preference_code_diff_display_mode';
+
+-- name: UpdateUserCodeDiffDisplayMode :one
+INSERT INTO
+	user_configs (user_id, key, value)
+VALUES
+	(@user_id, 'preference_code_diff_display_mode', @code_diff_display_mode::text)
+ON CONFLICT
+	ON CONSTRAINT user_configs_pkey
+DO UPDATE
+SET
+	value = @code_diff_display_mode
+WHERE user_configs.user_id = @user_id
+	AND user_configs.key = 'preference_code_diff_display_mode'
+RETURNING value AS code_diff_display_mode;
+
 -- name: UpdateUserRoles :one
 UPDATE
 	users

coderd/users.go

@@ -1248,9 +1248,19 @@ func (api *API) userPreferenceSettings(rw http.ResponseWriter, r *http.Request)
 		return
 	}
 
+	codeDiffMode, err := api.Database.GetUserCodeDiffDisplayMode(ctx, user.ID)
+	if err != nil && !errors.Is(err, sql.ErrNoRows) {
+		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "Error reading user preference settings.",
+			Detail:  err.Error(),
+		})
+		return
+	}
+
 	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserPreferenceSettings{
 		TaskNotificationAlertDismissed: taskAlertDismissed,
 		ThinkingDisplayMode:            sanitizeThinkingDisplayMode(thinkingMode),
+		CodeDiffDisplayMode:            sanitizeAgentDisplayMode(codeDiffMode),
 	})
 }
 
@@ -1280,69 +1290,120 @@ func (api *API) putUserPreferenceSettings(rw http.ResponseWriter, r *http.Reques
 		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
 			Message: "Invalid thinking display mode.",
 			Validations: []codersdk.ValidationError{
-				{Field: "thinking_display_mode", Detail: "must be one of: auto, preview, always_expanded, always_collapsed"},
+				{Field: "thinking_display_mode", Detail: thinkingDisplayModeValidationDetail},
 			},
 		})
 		return
 	}
-	var err error
-
-	var updatedTaskAlertDismissed bool
-	if params.TaskNotificationAlertDismissed != nil {
-		updatedTaskAlertDismissed, err = api.Database.UpdateUserTaskNotificationAlertDismissed(ctx, database.UpdateUserTaskNotificationAlertDismissedParams{
-			UserID:                         user.ID,
-			TaskNotificationAlertDismissed: *params.TaskNotificationAlertDismissed,
+	if params.CodeDiffDisplayMode != "" &&
+		!slices.Contains(codersdk.ValidAgentDisplayModes, params.CodeDiffDisplayMode) {
+		httpapi.Write(ctx, rw, http.StatusBadRequest, codersdk.Response{
+			Message: "Invalid code diff display mode.",
+			Validations: []codersdk.ValidationError{
+				{Field: "code_diff_display_mode", Detail: agentDisplayModeValidationDetail},
+			},
 		})
-		if err != nil {
-			httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-				Message: "Internal error updating user task notification alert dismissed.",
-				Detail:  err.Error(),
-			})
-			return
-		}
-	} else {
-		updatedTaskAlertDismissed, err = api.Database.GetUserTaskNotificationAlertDismissed(ctx, user.ID)
-		if err != nil && !errors.Is(err, sql.ErrNoRows) {
-			httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-				Message: "Error reading task notification alert dismissed.",
-				Detail:  err.Error(),
+		return
+	}
+	var settings codersdk.UserPreferenceSettings
+	err := api.Database.InTx(func(tx database.Store) error {
+		var err error
+		if params.TaskNotificationAlertDismissed != nil {
+			settings.TaskNotificationAlertDismissed, err = tx.UpdateUserTaskNotificationAlertDismissed(ctx, database.UpdateUserTaskNotificationAlertDismissedParams{
+				UserID:                         user.ID,
+				TaskNotificationAlertDismissed: *params.TaskNotificationAlertDismissed,
 			})
+			if err != nil {
+				return newUserPreferenceSettingsAPIError("Internal error updating user task notification alert dismissed.", err)
+			}
+		} else {
+			settings.TaskNotificationAlertDismissed, err = tx.GetUserTaskNotificationAlertDismissed(ctx, user.ID)
+			if err != nil && !errors.Is(err, sql.ErrNoRows) {
+				return newUserPreferenceSettingsAPIError("Error reading task notification alert dismissed.", err)
+			}
+		}
+
+		if params.ThinkingDisplayMode != "" {
+			updated, err := tx.UpdateUserThinkingDisplayMode(ctx, database.UpdateUserThinkingDisplayModeParams{
+				UserID:              user.ID,
+				ThinkingDisplayMode: string(params.ThinkingDisplayMode),
+			})
+			if err != nil {
+				return newUserPreferenceSettingsAPIError("Internal error updating thinking display mode.", err)
+			}
+			settings.ThinkingDisplayMode = sanitizeThinkingDisplayMode(updated)
+		} else {
+			stored, err := tx.GetUserThinkingDisplayMode(ctx, user.ID)
+			if err != nil && !errors.Is(err, sql.ErrNoRows) {
+				return newUserPreferenceSettingsAPIError("Error reading thinking display mode.", err)
+			}
+			settings.ThinkingDisplayMode = sanitizeThinkingDisplayMode(stored)
+		}
+
+		if params.CodeDiffDisplayMode != "" {
+			updated, err := tx.UpdateUserCodeDiffDisplayMode(ctx, database.UpdateUserCodeDiffDisplayModeParams{
+				UserID:              user.ID,
+				CodeDiffDisplayMode: string(params.CodeDiffDisplayMode),
+			})
+			if err != nil {
+				return newUserPreferenceSettingsAPIError("Internal error updating code diff display mode.", err)
+			}
+			settings.CodeDiffDisplayMode = sanitizeAgentDisplayMode(updated)
+		} else {
+			stored, err := tx.GetUserCodeDiffDisplayMode(ctx, user.ID)
+			if err != nil && !errors.Is(err, sql.ErrNoRows) {
+				return newUserPreferenceSettingsAPIError("Error reading code diff display mode.", err)
+			}
+			settings.CodeDiffDisplayMode = sanitizeAgentDisplayMode(stored)
+		}
+		return nil
+	}, database.DefaultTXOptions().WithID("user_preference_settings"))
+	if err != nil {
+		var apiErr userPreferenceSettingsAPIError
+		if errors.As(err, &apiErr) {
+			httpapi.Write(ctx, rw, apiErr.statusCode, apiErr.response)
 			return
 		}
+		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "Internal error updating user preference settings.",
+			Detail:  err.Error(),
+		})
+		return
 	}
 
-	var resolvedThinkingMode codersdk.ThinkingDisplayMode
-	if params.ThinkingDisplayMode != "" {
-		updated, err := api.Database.UpdateUserThinkingDisplayMode(ctx, database.UpdateUserThinkingDisplayModeParams{
-			UserID:              user.ID,
-			ThinkingDisplayMode: string(params.ThinkingDisplayMode),
-		})
-		if err != nil {
-			httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-				Message: "Internal error updating thinking display mode.",
-				Detail:  err.Error(),
-			})
-			return
-		}
-		resolvedThinkingMode = codersdk.ThinkingDisplayMode(updated)
-	} else {
-		stored, err := api.Database.GetUserThinkingDisplayMode(ctx, user.ID)
-		if err != nil && !errors.Is(err, sql.ErrNoRows) {
-			httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
-				Message: "Error reading thinking display mode.",
-				Detail:  err.Error(),
-			})
-			return
-		}
-		resolvedThinkingMode = sanitizeThinkingDisplayMode(stored)
-	}
-
-	httpapi.Write(ctx, rw, http.StatusOK, codersdk.UserPreferenceSettings{
-		TaskNotificationAlertDismissed: updatedTaskAlertDismissed,
-		ThinkingDisplayMode:            resolvedThinkingMode,
-	})
+	httpapi.Write(ctx, rw, http.StatusOK, settings)
 }
 
+type userPreferenceSettingsAPIError struct {
+	statusCode int
+	response   codersdk.Response
+	err        error
+}
+
+func newUserPreferenceSettingsAPIError(message string, err error) userPreferenceSettingsAPIError {
+	return userPreferenceSettingsAPIError{
+		statusCode: http.StatusInternalServerError,
+		response: codersdk.Response{
+			Message: message,
+			Detail:  err.Error(),
+		},
+		err: err,
+	}
+}
+
+func (e userPreferenceSettingsAPIError) Error() string {
+	return fmt.Sprintf("%s: %s", e.response.Message, e.err)
+}
+
+func (e userPreferenceSettingsAPIError) Unwrap() error {
+	return e.err
+}
+
+const (
+	thinkingDisplayModeValidationDetail = "must be one of: auto, preview, always_expanded, always_collapsed"
+	agentDisplayModeValidationDetail    = "must be one of: auto, always_expanded, always_collapsed"
+)
+
 func sanitizeThinkingDisplayMode(raw string) codersdk.ThinkingDisplayMode {
 	mode := codersdk.ThinkingDisplayMode(raw)
 	if slices.Contains(codersdk.ValidThinkingDisplayModes, mode) {
@@ -1351,6 +1412,14 @@ func sanitizeThinkingDisplayMode(raw string) codersdk.ThinkingDisplayMode {
 	return codersdk.ThinkingDisplayModeAuto
 }
 
+func sanitizeAgentDisplayMode(raw string) codersdk.AgentDisplayMode {
+	mode := codersdk.AgentDisplayMode(raw)
+	if slices.Contains(codersdk.ValidAgentDisplayModes, mode) {
+		return mode
+	}
+	return codersdk.AgentDisplayModeAuto
+}
+
 func isValidFontName(font codersdk.TerminalFontName) bool {
 	return slices.Contains(codersdk.TerminalFontNames, font)
 }

coderd/users_test.go

@@ -1963,6 +1963,117 @@ func TestThinkingDisplayMode(t *testing.T) {
 	})
 }
 
+func TestAgentDisplayModePreferences(t *testing.T) {
+	t.Parallel()
+
+	adminClient := coderdtest.New(t, nil)
+	firstUser := coderdtest.CreateFirstUser(t, adminClient)
+
+	requireValidationField := func(t *testing.T, err error, field string) {
+		t.Helper()
+
+		var sdkErr *codersdk.Error
+		require.ErrorAs(t, err, &sdkErr)
+		require.Equal(t, http.StatusBadRequest, sdkErr.StatusCode())
+		require.Len(t, sdkErr.Validations, 1)
+		require.Equal(t, field, sdkErr.Validations[0].Field)
+	}
+
+	t.Run("defaults to auto", func(t *testing.T) {
+		t.Parallel()
+
+		client, _ := coderdtest.CreateAnotherUser(t, adminClient, firstUser.OrganizationID)
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
+		defer cancel()
+
+		settings, err := client.GetUserPreferenceSettings(ctx, codersdk.Me)
+		require.NoError(t, err)
+		require.Equal(t, codersdk.AgentDisplayModeAuto, settings.CodeDiffDisplayMode)
+	})
+
+	t.Run("round-trips code diff display mode", func(t *testing.T) {
+		t.Parallel()
+
+		client, _ := coderdtest.CreateAnotherUser(t, adminClient, firstUser.OrganizationID)
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
+		defer cancel()
+
+		for _, mode := range []codersdk.AgentDisplayMode{
+			codersdk.AgentDisplayModeAlwaysExpanded,
+			codersdk.AgentDisplayModeAlwaysCollapsed,
+		} {
+			updated, err := client.UpdateUserPreferenceSettings(ctx, codersdk.Me, codersdk.UpdateUserPreferenceSettingsRequest{
+				CodeDiffDisplayMode: mode,
+			})
+			require.NoError(t, err)
+			require.Equal(t, mode, updated.CodeDiffDisplayMode)
+
+			settings, err := client.GetUserPreferenceSettings(ctx, codersdk.Me)
+			require.NoError(t, err)
+			require.Equal(t, mode, settings.CodeDiffDisplayMode)
+		}
+	})
+
+	t.Run("updates preserve stored display modes", func(t *testing.T) {
+		t.Parallel()
+
+		client, _ := coderdtest.CreateAnotherUser(t, adminClient, firstUser.OrganizationID)
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
+		defer cancel()
+
+		_, err := client.UpdateUserPreferenceSettings(ctx, codersdk.Me, codersdk.UpdateUserPreferenceSettingsRequest{
+			ThinkingDisplayMode: codersdk.ThinkingDisplayModePreview,
+			CodeDiffDisplayMode: codersdk.AgentDisplayModeAlwaysExpanded,
+		})
+		require.NoError(t, err)
+
+		updated, err := client.UpdateUserPreferenceSettings(ctx, codersdk.Me, codersdk.UpdateUserPreferenceSettingsRequest{
+			ThinkingDisplayMode: codersdk.ThinkingDisplayModeAlwaysExpanded,
+		})
+		require.NoError(t, err)
+		require.Equal(t, codersdk.ThinkingDisplayModeAlwaysExpanded, updated.ThinkingDisplayMode)
+		require.Equal(t, codersdk.AgentDisplayModeAlwaysExpanded, updated.CodeDiffDisplayMode)
+
+		settings, err := client.GetUserPreferenceSettings(ctx, codersdk.Me)
+		require.NoError(t, err)
+		require.Equal(t, codersdk.ThinkingDisplayModeAlwaysExpanded, settings.ThinkingDisplayMode)
+		require.Equal(t, codersdk.AgentDisplayModeAlwaysExpanded, settings.CodeDiffDisplayMode)
+	})
+
+	t.Run("rejects invalid code diff display mode", func(t *testing.T) {
+		t.Parallel()
+
+		client, _ := coderdtest.CreateAnotherUser(t, adminClient, firstUser.OrganizationID)
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitShort)
+		defer cancel()
+
+		for _, tt := range []struct {
+			name string
+			mode codersdk.AgentDisplayMode
+		}{
+			{
+				name: "bogus",
+				mode: codersdk.AgentDisplayMode("bogus"),
+			},
+			{
+				name: "thinking preview",
+				mode: codersdk.AgentDisplayMode(codersdk.ThinkingDisplayModePreview),
+			},
+		} {
+			t.Run(tt.name, func(t *testing.T) {
+				_, err := client.UpdateUserPreferenceSettings(ctx, codersdk.Me, codersdk.UpdateUserPreferenceSettingsRequest{
+					CodeDiffDisplayMode: tt.mode,
+				})
+				requireValidationField(t, err, "code_diff_display_mode")
+			})
+		}
+	})
+}
+
 func TestWorkspacesByUser(t *testing.T) {
 	t.Parallel()
 	t.Run("Empty", func(t *testing.T) {

codersdk/users.go

@@ -265,11 +265,13 @@ type UpdateUserAppearanceSettingsRequest struct {
 type UserPreferenceSettings struct {
 	TaskNotificationAlertDismissed bool                `json:"task_notification_alert_dismissed"`
 	ThinkingDisplayMode            ThinkingDisplayMode `json:"thinking_display_mode"`
+	CodeDiffDisplayMode            AgentDisplayMode    `json:"code_diff_display_mode"`
 }
 
 type UpdateUserPreferenceSettingsRequest struct {
 	TaskNotificationAlertDismissed *bool               `json:"task_notification_alert_dismissed,omitempty"`
 	ThinkingDisplayMode            ThinkingDisplayMode `json:"thinking_display_mode,omitempty"`
+	CodeDiffDisplayMode            AgentDisplayMode    `json:"code_diff_display_mode,omitempty"`
 }
 
 type ThinkingDisplayMode string
@@ -288,6 +290,20 @@ var ValidThinkingDisplayModes = []ThinkingDisplayMode{
 	ThinkingDisplayModeAlwaysCollapsed,
 }
 
+type AgentDisplayMode string
+
+const (
+	AgentDisplayModeAuto            AgentDisplayMode = "auto"
+	AgentDisplayModeAlwaysExpanded  AgentDisplayMode = "always_expanded"
+	AgentDisplayModeAlwaysCollapsed AgentDisplayMode = "always_collapsed"
+)
+
+var ValidAgentDisplayModes = []AgentDisplayMode{
+	AgentDisplayModeAuto,
+	AgentDisplayModeAlwaysExpanded,
+	AgentDisplayModeAlwaysCollapsed,
+}
+
 type UpdateUserPasswordRequest struct {
 	OldPassword string `json:"old_password" validate:""`
 	Password    string `json:"password" validate:"required"`

docs/reference/api/schemas.md

@@ -1431,6 +1431,20 @@
 | `workspace_agent_id`   | string                                       | false    |              |             |
 | `workspace_agent_name` | string                                       | false    |              |             |
 
+## codersdk.AgentDisplayMode
+
+```json
+"auto"
+```
+
+### Properties
+
+#### Enumerated Values
+
+| Value(s)                                      |
+|-----------------------------------------------|
+| `always_collapsed`, `always_expanded`, `auto` |
+
 ## codersdk.AgentScriptTiming
 
 ```json
@@ -12807,6 +12821,7 @@ Restarts will only happen on weekdays in this list on weeks which line up with W
 
 ```json
 {
+  "code_diff_display_mode": "auto",
   "task_notification_alert_dismissed": true,
   "thinking_display_mode": "auto"
 }
@@ -12816,6 +12831,7 @@ Restarts will only happen on weekdays in this list on weeks which line up with W
 
 | Name                                | Type                                                         | Required | Restrictions | Description |
 |-------------------------------------|--------------------------------------------------------------|----------|--------------|-------------|
+| `code_diff_display_mode`            | [codersdk.AgentDisplayMode](#codersdkagentdisplaymode)       | false    |              |             |
 | `task_notification_alert_dismissed` | boolean                                                      | false    |              |             |
 | `thinking_display_mode`             | [codersdk.ThinkingDisplayMode](#codersdkthinkingdisplaymode) | false    |              |             |
 
@@ -13393,6 +13409,7 @@ If the schedule is empty, the user will be updated to use the default schedule.|
 
 ```json
 {
+  "code_diff_display_mode": "auto",
   "task_notification_alert_dismissed": true,
   "thinking_display_mode": "auto"
 }
@@ -13402,6 +13419,7 @@ If the schedule is empty, the user will be updated to use the default schedule.|
 
 | Name                                | Type                                                         | Required | Restrictions | Description |
 |-------------------------------------|--------------------------------------------------------------|----------|--------------|-------------|
+| `code_diff_display_mode`            | [codersdk.AgentDisplayMode](#codersdkagentdisplaymode)       | false    |              |             |
 | `task_notification_alert_dismissed` | boolean                                                      | false    |              |             |
 | `thinking_display_mode`             | [codersdk.ThinkingDisplayMode](#codersdkthinkingdisplaymode) | false    |              |             |
 

docs/reference/api/users.md

@@ -1301,6 +1301,7 @@ curl -X GET http://coder-server:8080/api/v2/users/{user}/preferences \
 
 ```json
 {
+  "code_diff_display_mode": "auto",
   "task_notification_alert_dismissed": true,
   "thinking_display_mode": "auto"
 }
@@ -1332,6 +1333,7 @@ curl -X PUT http://coder-server:8080/api/v2/users/{user}/preferences \
 
 ```json
 {
+  "code_diff_display_mode": "auto",
   "task_notification_alert_dismissed": true,
   "thinking_display_mode": "auto"
 }
@@ -1350,6 +1352,7 @@ curl -X PUT http://coder-server:8080/api/v2/users/{user}/preferences \
 
 ```json
 {
+  "code_diff_display_mode": "auto",
   "task_notification_alert_dismissed": true,
   "thinking_display_mode": "auto"
 }

site/src/api/typesGenerated.ts

@@ -839,6 +839,15 @@ export interface AgentConnectionTiming {
 	readonly workspace_agent_name: string;
 }
 
+// From codersdk/users.go
+export type AgentDisplayMode = "always_collapsed" | "always_expanded" | "auto";
+
+export const AgentDisplayModes: AgentDisplayMode[] = [
+	"always_collapsed",
+	"always_expanded",
+	"auto",
+];
+
 // From codersdk/workspacebuilds.go
 export interface AgentScriptTiming {
 	readonly started_at: string;
@@ -8349,6 +8358,7 @@ export interface UpdateUserPasswordRequest {
 export interface UpdateUserPreferenceSettingsRequest {
 	readonly task_notification_alert_dismissed?: boolean;
 	readonly thinking_display_mode?: ThinkingDisplayMode;
+	readonly code_diff_display_mode?: AgentDisplayMode;
 }
 
 // From codersdk/users.go
@@ -8726,6 +8736,7 @@ export interface UserParameter {
 export interface UserPreferenceSettings {
 	readonly task_notification_alert_dismissed: boolean;
 	readonly thinking_display_mode: ThinkingDisplayMode;
+	readonly code_diff_display_mode: AgentDisplayMode;
 }
 
 // From codersdk/deployment.go

site/src/pages/AgentsPage/AgentSettingsGeneralPageView.stories.tsx

@@ -122,6 +122,27 @@ export const RendersChatLayoutSection: Story = {
 	},
 };
 
+export const RendersAgentDisplayModeSettings: Story = {
+	parameters: {
+		queries: [
+			{
+				key: ["me", "preferences"],
+				data: {
+					task_notification_alert_dismissed: false,
+					thinking_display_mode: "auto" as const,
+					code_diff_display_mode: "auto" as const,
+				},
+			},
+		],
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+
+		expect(await canvas.findByText("Thinking Display")).toBeVisible();
+		expect(await canvas.findByText("Code Diff Display")).toBeVisible();
+	},
+};
+
 export const ShowsChatDebugLoggingToggle: Story = {
 	args: {
 		userDebugLoggingData: {

site/src/pages/AgentsPage/AgentSettingsGeneralPageView.tsx

@@ -2,9 +2,12 @@ import type { FC } from "react";
 import type { UseMutateFunction } from "react-query";
 import type * as TypesGen from "#/api/typesGenerated";
 import { ChatFullWidthSettings } from "./components/ChatFullWidthSettings";
+import {
+	CodeDiffDisplaySettings,
+	ThinkingDisplaySettings,
+} from "./components/DisplayModeSettings";
 import { PersonalInstructionsSettings } from "./components/PersonalInstructionsSettings";
 import { SectionHeader } from "./components/SectionHeader";
-import { ThinkingDisplaySettings } from "./components/ThinkingDisplaySettings";
 import { UserChatDebugLoggingSettings } from "./components/UserChatDebugLoggingSettings";
 
 export interface AgentSettingsGeneralPageViewProps {
@@ -55,6 +58,7 @@ export const AgentSettingsGeneralPageView: FC<
 			/>
 			<ChatFullWidthSettings />
 			<ThinkingDisplaySettings />
+			<CodeDiffDisplaySettings />
 			<UserChatDebugLoggingSettings
 				userSettings={userDebugLoggingData}
 				onSaveUserSetting={onSaveUserDebugLogging}

site/src/pages/AgentsPage/components/ChatConversation/ConversationTimeline.stories.tsx

@@ -14,6 +14,7 @@ import { getChatFileURL } from "../../utils/chatAttachments";
 import { encodeInlineTextAttachment } from "../../utils/fetchTextAttachment";
 import { ConversationTimeline } from "./ConversationTimeline";
 import { parseMessagesWithMergedTools } from "./messageParsing";
+import type { ParsedMessageEntry } from "./types";
 
 // 1×1 solid coral (#FF6B6B) PNG encoded as base64.
 const TEST_PNG_B64 =
@@ -1753,6 +1754,78 @@ export const AssistantActionBarAfterHiddenMessages: Story = {
 	},
 };
 
+export const CodeDiffDisplayModeFromPreferences: Story = {
+	parameters: {
+		queries: [
+			{
+				key: ["me", "preferences"],
+				data: {
+					task_notification_alert_dismissed: false,
+					thinking_display_mode: "auto" as const,
+					code_diff_display_mode: "always_collapsed" as const,
+				},
+			},
+		],
+	},
+	args: {
+		...defaultArgs,
+		parsedMessages: [
+			{
+				message: {
+					...baseMessage,
+					id: 1,
+					role: "assistant",
+					content: [],
+				},
+				parsed: {
+					markdown: "",
+					reasoning: "",
+					toolCalls: [],
+					toolResults: [],
+					tools: [
+						{
+							id: "edit-tool",
+							name: "edit_files",
+							args: {
+								files: [
+									{
+										path: "src/config.ts",
+										edits: [
+											{
+												search: "const timeout = 30;",
+												replace: "const timeout = 60;",
+											},
+										],
+									},
+								],
+							},
+							result: { ok: true },
+							isError: false,
+							status: "completed",
+						},
+					],
+					blocks: [{ type: "tool", id: "edit-tool" }],
+					sources: [],
+				},
+			},
+		] satisfies ParsedMessageEntry[],
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		expect(canvas.getByText(/Edited config\.ts/)).toBeVisible();
+		expect(canvas.queryAllByTestId("edit-file-diff")).toHaveLength(0);
+
+		const editFilesButton = canvas.getByRole("button", {
+			name: /Edited config\.ts/,
+		});
+		expect(editFilesButton).toHaveAttribute("aria-expanded", "false");
+		await userEvent.click(editFilesButton);
+		await waitFor(() => {
+			expect(canvas.getAllByTestId("edit-file-diff")).toHaveLength(1);
+		});
+	},
+};
+
 /**
  * A completed thinking block with always_expanded mode should show
  * its content without user interaction.
@@ -1765,6 +1838,7 @@ export const ThinkingBlockAlwaysExpanded: Story = {
 				data: {
 					task_notification_alert_dismissed: false,
 					thinking_display_mode: "always_expanded" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],
@@ -1812,6 +1886,7 @@ export const ThinkingBlockAlwaysCollapsed: Story = {
 				data: {
 					task_notification_alert_dismissed: false,
 					thinking_display_mode: "always_collapsed" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],
@@ -1860,6 +1935,7 @@ export const ThinkingBlockWithToolCall: Story = {
 				data: {
 					task_notification_alert_dismissed: false,
 					thinking_display_mode: "always_collapsed" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],
@@ -1921,6 +1997,7 @@ export const ThinkingBlockAutoMode: Story = {
 				data: {
 					task_notification_alert_dismissed: false,
 					thinking_display_mode: "auto" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],
@@ -1972,6 +2049,7 @@ export const ThinkingBlockPreviewMode: Story = {
 				data: {
 					task_notification_alert_dismissed: false,
 					thinking_display_mode: "preview" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],

site/src/pages/AgentsPage/components/ChatConversation/ConversationTimeline.tsx

@@ -275,6 +275,8 @@ export const BlockList: FC<{
 	const prefQuery = useQuery(preferenceSettings());
 	const thinkingDisplayMode: ThinkingDisplayMode =
 		prefQuery.data?.thinking_display_mode || "auto";
+	const codeDiffDisplayMode: TypesGen.AgentDisplayMode =
+		prefQuery.data?.code_diff_display_mode || "auto";
 
 	const toolByID = new Map(tools.map((tool) => [tool.id, tool]));
 
@@ -365,6 +367,7 @@ export const BlockList: FC<{
 									name="Tool"
 									status="running"
 									isError={false}
+									codeDiffDisplayMode={codeDiffDisplayMode}
 									subagentTitles={subagentTitles}
 									subagentVariants={subagentVariants}
 									subagentStatusOverrides={subagentStatusOverrides}
@@ -381,6 +384,7 @@ export const BlockList: FC<{
 								status={tool.status}
 								isError={tool.isError}
 								killedBySignal={tool.killedBySignal}
+								codeDiffDisplayMode={codeDiffDisplayMode}
 								subagentTitles={subagentTitles}
 								subagentVariants={subagentVariants}
 								showDesktopPreviews={showDesktopPreviews}
@@ -436,6 +440,7 @@ export const BlockList: FC<{
 					status={tool.status}
 					isError={tool.isError}
 					killedBySignal={tool.killedBySignal}
+					codeDiffDisplayMode={codeDiffDisplayMode}
 					subagentTitles={subagentTitles}
 					subagentVariants={subagentVariants}
 					showDesktopPreviews={showDesktopPreviews}

site/src/pages/AgentsPage/components/ChatElements/tools/EditFilesTool.tsx

@@ -3,13 +3,19 @@ import type { FileDiffMetadata } from "@pierre/diffs";
 import { FileDiff } from "@pierre/diffs/react";
 import { LoaderIcon, TriangleAlertIcon } from "lucide-react";
 import type React from "react";
+import type * as TypesGen from "#/api/typesGenerated";
 import { ScrollArea } from "#/components/ScrollArea/ScrollArea";
 import {
 	Tooltip,
 	TooltipContent,
 	TooltipTrigger,
 } from "#/components/Tooltip/Tooltip";
-import { ToolCollapsible } from "./ToolCollapsible";
+import {
+	type AgentDisplayState,
+	isAgentDisplayFullyExpanded,
+	resolveAgentDisplayState,
+} from "./displayMode";
+import { AgentDisplayModeToolCollapsible } from "./ToolCollapsible";
 import {
 	DIFFS_FONT_STYLE,
 	type EditFilesFileEntry,
@@ -18,22 +24,24 @@ import {
 	type ToolStatus,
 } from "./utils";
 
-/**
- * Collapsed-by-default rendering for `edit_files` tool calls.
- * Shows "Edited <filename>" (or "Edited N files") with a chevron;
- * expanding reveals a unified diff for each file.
- */
+const EDIT_FILES_AUTO_DISPLAY_STATE: AgentDisplayState = "preview";
+
 export const EditFilesTool: React.FC<{
 	files: EditFilesFileEntry[];
 	diffs: (FileDiffMetadata | null)[];
 	status: ToolStatus;
 	isError: boolean;
 	errorMessage?: string;
-}> = ({ files, diffs, status, isError, errorMessage }) => {
+	codeDiffDisplayMode?: TypesGen.AgentDisplayMode;
+}> = ({ files, diffs, status, isError, errorMessage, codeDiffDisplayMode }) => {
 	const theme = useTheme();
 	const isDark = theme.palette.mode === "dark";
 	const isRunning = status === "running";
 	const hasDiffs = diffs.some((d) => d !== null);
+	const displayState = resolveAgentDisplayState(
+		codeDiffDisplayMode,
+		EDIT_FILES_AUTO_DISPLAY_STATE,
+	);
 
 	let label: string;
 	if (isRunning) {
@@ -54,10 +62,11 @@ export const EditFilesTool: React.FC<{
 	}
 
 	return (
-		<ToolCollapsible
+		<AgentDisplayModeToolCollapsible
 			className="w-full"
 			hasContent={hasDiffs}
-			defaultExpanded
+			displayMode={codeDiffDisplayMode}
+			autoDisplayState={EDIT_FILES_AUTO_DISPLAY_STATE}
 			header={
 				<>
 					<span className="text-[13px]">{label}</span>
@@ -84,7 +93,11 @@ export const EditFilesTool: React.FC<{
 							key={files[i].path}
 							data-testid="edit-file-diff"
 							className="rounded-md border border-solid border-border-default text-2xs"
-							viewportClassName="max-h-64"
+							viewportClassName={
+								isAgentDisplayFullyExpanded(displayState)
+									? "max-h-[80vh]"
+									: "max-h-64"
+							}
 							scrollBarClassName="w-1.5"
 						>
 							<FileDiff
@@ -96,6 +109,6 @@ export const EditFilesTool: React.FC<{
 					) : null,
 				)}
 			</div>
-		</ToolCollapsible>
+		</AgentDisplayModeToolCollapsible>
 	);
 };

site/src/pages/AgentsPage/components/ChatElements/tools/Tool.stories.tsx

@@ -51,6 +51,10 @@ export const ExecuteSuccess: Story = {
 				"From github.com:coder/coder\n * [new branch]      feature/agent-ui -> origin/feature/agent-ui",
 		},
 	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		expect(canvas.getByText(/From github\.com:coder\/coder/)).toBeVisible();
+	},
 };
 
 export const ExecuteAuthRequired: Story = {
@@ -983,6 +987,7 @@ export const WriteFileSuccess: Story = {
 	args: {
 		name: "write_file",
 		status: "completed",
+		codeDiffDisplayMode: "auto",
 		args: {
 			path: "src/utils/helpers.ts",
 			content:
@@ -992,6 +997,30 @@ export const WriteFileSuccess: Story = {
 	play: async ({ canvasElement }) => {
 		const canvas = within(canvasElement);
 		expect(canvas.getByText(/Wrote helpers\.ts/)).toBeInTheDocument();
+		expect(canvas.queryByTestId("write-file-diff")).not.toBeInTheDocument();
+		await userEvent.click(
+			canvas.getByRole("button", { name: /Wrote helpers\.ts/ }),
+		);
+		await waitFor(() => {
+			expect(canvas.getByTestId("write-file-diff")).toBeVisible();
+		});
+	},
+};
+
+export const WriteFileAlwaysExpanded: Story = {
+	args: {
+		name: "write_file",
+		status: "completed",
+		codeDiffDisplayMode: "always_expanded",
+		args: {
+			path: "src/utils/helpers.ts",
+			content:
+				"export function greet(name: string): string {\n  return `Hello, ${name}!`;\n}\n",
+		},
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		expect(canvas.getByTestId("write-file-diff")).toBeVisible();
 	},
 };
 
@@ -1027,6 +1056,7 @@ export const EditFilesSingleSuccess: Story = {
 	args: {
 		name: "edit_files",
 		status: "completed",
+		codeDiffDisplayMode: "auto",
 		args: {
 			files: [
 				{
@@ -1044,6 +1074,39 @@ export const EditFilesSingleSuccess: Story = {
 	play: async ({ canvasElement }) => {
 		const canvas = within(canvasElement);
 		expect(canvas.getByText(/Edited config\.ts/)).toBeInTheDocument();
+		expect(canvas.getAllByTestId("edit-file-diff")).toHaveLength(1);
+	},
+};
+
+export const EditFilesAlwaysCollapsed: Story = {
+	args: {
+		name: "edit_files",
+		status: "completed",
+		codeDiffDisplayMode: "always_collapsed",
+		args: {
+			files: [
+				{
+					path: "src/config.ts",
+					edits: [
+						{
+							search: "const timeout = 30;",
+							replace: "const timeout = 60;",
+						},
+					],
+				},
+			],
+		},
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		expect(canvas.getByText(/Edited config\.ts/)).toBeVisible();
+		expect(canvas.queryAllByTestId("edit-file-diff")).toHaveLength(0);
+		await userEvent.click(
+			canvas.getByRole("button", { name: /Edited config\.ts/ }),
+		);
+		await waitFor(() => {
+			expect(canvas.getAllByTestId("edit-file-diff")).toHaveLength(1);
+		});
 	},
 };
 

site/src/pages/AgentsPage/components/ChatElements/tools/Tool.tsx

@@ -1,5 +1,5 @@
 import { useTheme } from "@emotion/react";
-import { FileDiff, File as FileViewer } from "@pierre/diffs/react";
+import { File as FileViewer } from "@pierre/diffs/react";
 import { LoaderIcon, TriangleAlertIcon } from "lucide-react";
 import { type ComponentPropsWithRef, type FC, memo } from "react";
 import type * as TypesGen from "#/api/typesGenerated";
@@ -49,7 +49,6 @@ import {
 	buildEditDiff,
 	DIFFS_FONT_STYLE,
 	formatResultOutput,
-	getDiffViewerOptions,
 	getFileContentForViewer,
 	getFileViewerOptions,
 	getFileViewerOptionsNoHeader,
@@ -60,7 +59,6 @@ import {
 	parseEditFilesArgs,
 	parseServerEditDiffText,
 	parseServerEditResults,
-	stripNoNewline,
 	type ToolStatus,
 	toProviderLabel,
 } from "./utils";
@@ -94,6 +92,7 @@ interface ToolProps extends Omit<ComponentPropsWithRef<"div">, "children"> {
 	previousResponseText?: string;
 	/** Human-readable intent extracted from the model's tool-call args. */
 	modelIntent?: string;
+	codeDiffDisplayMode?: TypesGen.AgentDisplayMode;
 }
 
 // Props passed to each tool-specific renderer function. Each renderer
@@ -117,6 +116,7 @@ type ToolRendererProps = {
 	mcpServerConfigId?: string;
 	mcpServers?: readonly TypesGen.MCPServerConfig[];
 	modelIntent?: string;
+	codeDiffDisplayMode?: TypesGen.AgentDisplayMode;
 };
 
 // ---------------------------------------------------------------------------
@@ -369,6 +369,7 @@ const WriteFileRenderer: FC<ToolRendererProps> = ({
 	args,
 	result,
 	isError,
+	codeDiffDisplayMode,
 }) => {
 	const parsedArgs = parseArgs(args);
 	const path = parsedArgs ? asString(parsedArgs.path).trim() : "";
@@ -382,6 +383,7 @@ const WriteFileRenderer: FC<ToolRendererProps> = ({
 			status={status}
 			isError={isError}
 			errorMessage={rec ? asString(rec.error || rec.message) : undefined}
+			codeDiffDisplayMode={codeDiffDisplayMode}
 		/>
 	);
 };
@@ -391,6 +393,7 @@ const EditFilesRenderer: FC<ToolRendererProps> = ({
 	args,
 	result,
 	isError,
+	codeDiffDisplayMode,
 }) => {
 	const rec = asRecord(result);
 	const editFiles = parseEditFilesArgs(args);
@@ -413,6 +416,7 @@ const EditFilesRenderer: FC<ToolRendererProps> = ({
 			status={status}
 			isError={isError}
 			errorMessage={rec ? asString(rec.error || rec.message) : undefined}
+			codeDiffDisplayMode={codeDiffDisplayMode}
 		/>
 	);
 };
@@ -814,8 +818,6 @@ const ComputerRenderer: FC<ToolRendererProps> = ({
 	);
 };
 
-// Generic fallback renderer — only path that needs theme, diff
-// viewers, and file content helpers.
 const GenericToolRenderer: FC<ToolRendererProps> = ({
 	name,
 	status,
@@ -830,7 +832,6 @@ const GenericToolRenderer: FC<ToolRendererProps> = ({
 	const isDark = theme.palette.mode === "dark";
 	const resultOutput = formatResultOutput(result);
 	const fileContent = getFileContentForViewer(name, args, result);
-	const writeFileDiff = getWriteFileDiff(name, args);
 	const fileViewerOpts = getFileViewerOptions(isDark);
 	const fileContentOptions = fileContent
 		? {
@@ -845,64 +846,49 @@ const GenericToolRenderer: FC<ToolRendererProps> = ({
 		? mcpServers?.find((s) => s.id === mcpServerConfigId)
 		: undefined;
 
-	const hasContent = Boolean(writeFileDiff || fileContent || resultOutput);
+	const hasContent = Boolean(fileContent || resultOutput);
 	const isRunning = status === "running";
 	const rec = asRecord(result);
 	const errorMessage = rec ? asString(rec.error || rec.message) : "";
 
-	return (
-		<ToolCollapsible
-			hasContent={hasContent}
-			header={
-				<>
-					<ToolIcon
-						name={name}
-						isError={status === "error" || isError}
-						iconUrl={mcpServer?.icon_url}
-						isRunning={isRunning}
-						serverName={mcpServer?.display_name}
-					/>
-					{modelIntent ? (
-						<span className="truncate text-[13px]">
-							{modelIntent.charAt(0).toUpperCase() + modelIntent.slice(1)}
-						</span>
-					) : (
-						<ToolLabel
-							name={name}
-							args={args}
-							result={result}
-							mcpSlug={mcpServer?.slug}
-						/>
-					)}
-					{isError && (
-						<Tooltip>
-							<TooltipTrigger asChild>
-								<TriangleAlertIcon className="h-3.5 w-3.5 shrink-0 text-current" />
-							</TooltipTrigger>
-							<TooltipContent>
-								{errorMessage || "Tool call failed"}
-							</TooltipContent>
-						</Tooltip>
-					)}
-					{isRunning && (
-						<LoaderIcon className="h-3.5 w-3.5 shrink-0 animate-spin motion-reduce:animate-none text-current" />
-					)}
-				</>
-			}
-		>
-			{writeFileDiff ? (
-				<ScrollArea
-					className="mt-1.5 rounded-md border border-solid border-border-default text-2xs"
-					viewportClassName="max-h-64"
-					scrollBarClassName="w-1.5"
-				>
-					<FileDiff
-						fileDiff={stripNoNewline(writeFileDiff)}
-						options={getDiffViewerOptions(isDark)}
-						style={DIFFS_FONT_STYLE}
-					/>
-				</ScrollArea>
-			) : fileContent ? (
+	const toolHeader = (
+		<>
+			<ToolIcon
+				name={name}
+				isError={status === "error" || isError}
+				iconUrl={mcpServer?.icon_url}
+				isRunning={isRunning}
+				serverName={mcpServer?.display_name}
+			/>
+			{modelIntent ? (
+				<span className="truncate text-[13px]">
+					{modelIntent.charAt(0).toUpperCase() + modelIntent.slice(1)}
+				</span>
+			) : (
+				<ToolLabel
+					name={name}
+					args={args}
+					result={result}
+					mcpSlug={mcpServer?.slug}
+				/>
+			)}
+			{isError && (
+				<Tooltip>
+					<TooltipTrigger asChild>
+						<TriangleAlertIcon className="h-3.5 w-3.5 shrink-0 text-current" />
+					</TooltipTrigger>
+					<TooltipContent>{errorMessage || "Tool call failed"}</TooltipContent>
+				</Tooltip>
+			)}
+			{isRunning && (
+				<LoaderIcon className="h-3.5 w-3.5 shrink-0 animate-spin motion-reduce:animate-none text-current" />
+			)}
+		</>
+	);
+
+	const toolContent = (
+		<>
+			{fileContent ? (
 				<ScrollArea
 					className="mt-1.5 rounded-md border border-solid border-border-default text-2xs"
 					viewportClassName="max-h-64"
@@ -935,6 +921,12 @@ const GenericToolRenderer: FC<ToolRendererProps> = ({
 					</ScrollArea>
 				)
 			)}
+		</>
+	);
+
+	return (
+		<ToolCollapsible hasContent={hasContent} header={toolHeader}>
+			{toolContent}
 		</ToolCollapsible>
 	);
 };
@@ -1030,6 +1022,7 @@ export const Tool = memo(
 		isLatestAskUserQuestion,
 		previousResponseText,
 		modelIntent,
+		codeDiffDisplayMode,
 		ref,
 		...props
 	}: ToolProps) => {
@@ -1076,6 +1069,7 @@ export const Tool = memo(
 					isLatestAskUserQuestion={isLatestAskUserQuestion}
 					previousResponseText={previousResponseText}
 					modelIntent={modelIntent}
+					codeDiffDisplayMode={codeDiffDisplayMode}
 				/>
 			</div>
 		);

site/src/pages/AgentsPage/components/ChatElements/tools/ToolCollapsible.tsx

@@ -1,7 +1,13 @@
 import { ChevronDownIcon } from "lucide-react";
 import type { FC, ReactNode } from "react";
 import { useState } from "react";
+import type { AgentDisplayMode } from "#/api/typesGenerated";
 import { cn } from "#/utils/cn";
+import {
+	type AgentDisplayState,
+	isAgentDisplayOpen,
+	resolveAgentDisplayState,
+} from "./displayMode";
 
 type ToolCollapsibleHeader = ReactNode | ((expanded: boolean) => ReactNode);
 
@@ -14,6 +20,25 @@ interface ToolCollapsibleProps {
 	headerClassName?: string;
 }
 
+interface AgentDisplayModeToolCollapsibleProps
+	extends Omit<ToolCollapsibleProps, "defaultExpanded"> {
+	displayMode: AgentDisplayMode | undefined;
+	autoDisplayState: AgentDisplayState;
+}
+
+export const AgentDisplayModeToolCollapsible: FC<
+	AgentDisplayModeToolCollapsibleProps
+> = ({ displayMode, autoDisplayState, ...props }) => {
+	const displayState = resolveAgentDisplayState(displayMode, autoDisplayState);
+	return (
+		<ToolCollapsible
+			key={`${displayMode ?? "auto"}:${autoDisplayState}`}
+			{...props}
+			defaultExpanded={isAgentDisplayOpen(displayState)}
+		/>
+	);
+};
+
 export const ToolCollapsible: FC<ToolCollapsibleProps> = ({
 	children,
 	header,

site/src/pages/AgentsPage/components/ChatElements/tools/WriteFileTool.tsx

@@ -3,13 +3,19 @@ import type { FileDiffMetadata } from "@pierre/diffs";
 import { FileDiff } from "@pierre/diffs/react";
 import { LoaderIcon, TriangleAlertIcon } from "lucide-react";
 import type React from "react";
+import type * as TypesGen from "#/api/typesGenerated";
 import { ScrollArea } from "#/components/ScrollArea/ScrollArea";
 import {
 	Tooltip,
 	TooltipContent,
 	TooltipTrigger,
 } from "#/components/Tooltip/Tooltip";
-import { ToolCollapsible } from "./ToolCollapsible";
+import {
+	type AgentDisplayState,
+	isAgentDisplayFullyExpanded,
+	resolveAgentDisplayState,
+} from "./displayMode";
+import { AgentDisplayModeToolCollapsible } from "./ToolCollapsible";
 import {
 	DIFFS_FONT_STYLE,
 	getDiffViewerOptions,
@@ -17,29 +23,34 @@ import {
 	type ToolStatus,
 } from "./utils";
 
-/**
- * Collapsed-by-default rendering for `write_file` tool calls. Shows
- * "Wrote <filename>" with a chevron; expanding reveals the unified diff.
- */
+const WRITE_FILE_AUTO_DISPLAY_STATE: AgentDisplayState = "collapsed";
+
 export const WriteFileTool: React.FC<{
 	path: string;
 	diff: FileDiffMetadata | null;
 	status: ToolStatus;
 	isError: boolean;
 	errorMessage?: string;
-}> = ({ path, diff, status, isError, errorMessage }) => {
+	codeDiffDisplayMode?: TypesGen.AgentDisplayMode;
+}> = ({ path, diff, status, isError, errorMessage, codeDiffDisplayMode }) => {
 	const theme = useTheme();
 	const isDark = theme.palette.mode === "dark";
 	const hasDiff = diff !== null;
 	const isRunning = status === "running";
+	const displayState = resolveAgentDisplayState(
+		codeDiffDisplayMode,
+		WRITE_FILE_AUTO_DISPLAY_STATE,
+	);
 
 	const filename = path.split("/").pop() || path;
 	const label = isRunning ? `Writing ${filename}…` : `Wrote ${filename}`;
 
 	return (
-		<ToolCollapsible
+		<AgentDisplayModeToolCollapsible
 			className="w-full"
 			hasContent={hasDiff}
+			displayMode={codeDiffDisplayMode}
+			autoDisplayState={WRITE_FILE_AUTO_DISPLAY_STATE}
 			header={
 				<>
 					<span className="text-[13px]">{label}</span>
@@ -61,8 +72,13 @@ export const WriteFileTool: React.FC<{
 		>
 			{hasDiff && (
 				<ScrollArea
+					data-testid="write-file-diff"
 					className="mt-1.5 rounded-md border border-solid border-border-default text-2xs"
-					viewportClassName="max-h-64"
+					viewportClassName={
+						isAgentDisplayFullyExpanded(displayState)
+							? "max-h-[80vh]"
+							: "max-h-64"
+					}
 					scrollBarClassName="w-1.5"
 				>
 					<FileDiff
@@ -72,6 +88,6 @@ export const WriteFileTool: React.FC<{
 					/>
 				</ScrollArea>
 			)}
-		</ToolCollapsible>
+		</AgentDisplayModeToolCollapsible>
 	);
 };

site/src/pages/AgentsPage/components/ChatElements/tools/displayMode.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from "vitest";
+
+import {
+	isAgentDisplayFullyExpanded,
+	isAgentDisplayOpen,
+	resolveAgentDisplayState,
+} from "./displayMode";
+
+describe("resolveAgentDisplayState", () => {
+	it("resolves auto and explicit display modes", () => {
+		expect(resolveAgentDisplayState(undefined, "preview")).toBe("preview");
+		expect(resolveAgentDisplayState("auto", "collapsed")).toBe("collapsed");
+		expect(resolveAgentDisplayState("auto", "expanded")).toBe("expanded");
+		expect(resolveAgentDisplayState("always_expanded", "collapsed")).toBe(
+			"expanded",
+		);
+		expect(resolveAgentDisplayState("always_collapsed", "expanded")).toBe(
+			"collapsed",
+		);
+	});
+});
+
+describe("isAgentDisplayOpen", () => {
+	it("returns whether a display state shows content", () => {
+		expect(isAgentDisplayOpen("collapsed")).toBe(false);
+		expect(isAgentDisplayOpen("preview")).toBe(true);
+		expect(isAgentDisplayOpen("expanded")).toBe(true);
+	});
+});
+
+describe("isAgentDisplayFullyExpanded", () => {
+	it("returns whether a display state uses a fully expanded view", () => {
+		expect(isAgentDisplayFullyExpanded("expanded")).toBe(true);
+		expect(isAgentDisplayFullyExpanded("preview")).toBe(false);
+		expect(isAgentDisplayFullyExpanded("collapsed")).toBe(false);
+	});
+});

site/src/pages/AgentsPage/components/ChatElements/tools/displayMode.ts

@@ -0,0 +1,32 @@
+import type { AgentDisplayMode } from "#/api/typesGenerated";
+
+export type AgentDisplayState = "collapsed" | "preview" | "expanded";
+
+export const resolveAgentDisplayState = (
+	mode: AgentDisplayMode | undefined,
+	autoState: AgentDisplayState,
+): AgentDisplayState => {
+	switch (mode) {
+		case undefined:
+		case "auto":
+			return autoState;
+		case "always_expanded":
+			return "expanded";
+		case "always_collapsed":
+			return "collapsed";
+		default: {
+			const _exhaustive: never = mode;
+			return _exhaustive;
+		}
+	}
+};
+
+export const isAgentDisplayOpen = (state: AgentDisplayState): boolean => {
+	return state !== "collapsed";
+};
+
+export const isAgentDisplayFullyExpanded = (
+	state: AgentDisplayState,
+): boolean => {
+	return state === "expanded";
+};

site/src/pages/AgentsPage/components/DisplayModeSettings.tsx

@@ -0,0 +1,133 @@
+import type { FC } from "react";
+import { useMutation, useQuery, useQueryClient } from "react-query";
+import {
+	preferenceSettings,
+	updatePreferenceSettings,
+} from "#/api/queries/users";
+import type {
+	UpdateUserPreferenceSettingsRequest,
+	UserPreferenceSettings,
+} from "#/api/typesGenerated";
+import {
+	Select,
+	SelectContent,
+	SelectItem,
+	SelectTrigger,
+	SelectValue,
+} from "#/components/Select/Select";
+
+type DisplayModeOption<T extends string> = { value: T; label: string };
+
+type ThinkingDisplayMode = UserPreferenceSettings["thinking_display_mode"];
+type AgentDisplayMode = UserPreferenceSettings["code_diff_display_mode"];
+
+const thinkingDisplayOptions: DisplayModeOption<ThinkingDisplayMode>[] = [
+	{ value: "auto", label: "Auto" },
+	{ value: "preview", label: "Preview" },
+	{ value: "always_expanded", label: "Always Expanded" },
+	{ value: "always_collapsed", label: "Always Collapsed" },
+];
+
+const agentDisplayOptions: DisplayModeOption<AgentDisplayMode>[] = [
+	{ value: "auto", label: "Auto" },
+	{ value: "always_expanded", label: "Always Expanded" },
+	{ value: "always_collapsed", label: "Always Collapsed" },
+];
+
+type DisplayModeSettingsProps<T extends string> = {
+	title: string;
+	description: string;
+	ariaLabel: string;
+	errorMessage: string;
+	defaultValue: T;
+	options: DisplayModeOption<T>[];
+	getMode: (settings: UserPreferenceSettings) => T;
+	updateSettings: (value: T) => UpdateUserPreferenceSettingsRequest;
+};
+
+const DisplayModeSettings = <T extends string>({
+	title,
+	description,
+	ariaLabel,
+	errorMessage,
+	defaultValue,
+	options,
+	getMode,
+	updateSettings,
+}: DisplayModeSettingsProps<T>) => {
+	const queryClient = useQueryClient();
+	const query = useQuery(preferenceSettings());
+	const mutation = useMutation(updatePreferenceSettings(queryClient));
+
+	const mode = query.data ? getMode(query.data) : defaultValue;
+
+	return (
+		<div className="flex flex-col gap-2">
+			<h3 className="m-0 text-sm font-semibold text-content-primary">
+				{title}
+			</h3>
+			<div className="flex items-center justify-between gap-4">
+				<p className="m-0 flex-1 text-xs text-content-secondary">
+					{description}
+				</p>
+				<Select
+					value={mode}
+					disabled={query.isLoading || !query.data}
+					onValueChange={(value: string) => {
+						const selected = options.find((opt) => opt.value === value);
+						if (!query.data || !selected) return;
+						mutation.mutate(updateSettings(selected.value));
+					}}
+				>
+					<SelectTrigger className="w-44 shrink-0" aria-label={ariaLabel}>
+						<SelectValue />
+					</SelectTrigger>
+					<SelectContent>
+						{options.map((opt) => (
+							<SelectItem key={opt.value} value={opt.value}>
+								{opt.label}
+							</SelectItem>
+						))}
+					</SelectContent>
+				</Select>
+			</div>
+			{mutation.isError && (
+				<p className="m-0 text-xs text-content-destructive">{errorMessage}</p>
+			)}
+		</div>
+	);
+};
+
+export const ThinkingDisplaySettings: FC = () => {
+	return (
+		<DisplayModeSettings
+			title="Thinking Display"
+			description="How thinking blocks should be displayed by default. 'Auto' fully expands during streaming, then auto-collapses when done. 'Preview' auto-expands with a height constraint during streaming. 'Always Expanded' shows full content. 'Always Collapsed' keeps them collapsed."
+			ariaLabel="Thinking display mode"
+			errorMessage="Failed to save your thinking display preference."
+			defaultValue="auto"
+			options={thinkingDisplayOptions}
+			getMode={(settings) => settings.thinking_display_mode}
+			updateSettings={(value) => ({
+				thinking_display_mode: value,
+			})}
+		/>
+	);
+};
+
+export const CodeDiffDisplaySettings: FC = () => {
+	return (
+		<DisplayModeSettings
+			title="Code Diff Display"
+			description="Controls how code edit diffs appear. Auto starts single-file writes collapsed and opens multi-file edits with a height-constrained preview. Always Expanded opens diffs by default; Always Collapsed keeps them collapsed."
+			ariaLabel="Code diff display mode"
+			errorMessage="Failed to save your code diff display preference."
+			defaultValue="auto"
+			options={agentDisplayOptions}
+			getMode={(settings) => settings.code_diff_display_mode}
+			updateSettings={(value) => ({
+				code_diff_display_mode: value,
+			})}
+		/>
+	);
+};

site/src/pages/AgentsPage/components/ThinkingDisplaySettings.tsx

@@ -1,75 +0,0 @@
-import type { FC } from "react";
-import { useMutation, useQuery, useQueryClient } from "react-query";
-import {
-	preferenceSettings,
-	updatePreferenceSettings,
-} from "#/api/queries/users";
-import type { ThinkingDisplayMode } from "#/api/typesGenerated";
-import {
-	Select,
-	SelectContent,
-	SelectItem,
-	SelectTrigger,
-	SelectValue,
-} from "#/components/Select/Select";
-
-const options: { value: ThinkingDisplayMode; label: string }[] = [
-	{ value: "auto", label: "Auto" },
-	{ value: "preview", label: "Preview" },
-	{ value: "always_expanded", label: "Always Expanded" },
-	{ value: "always_collapsed", label: "Always Collapsed" },
-];
-
-export const ThinkingDisplaySettings: FC = () => {
-	const queryClient = useQueryClient();
-	const query = useQuery(preferenceSettings());
-	const mutation = useMutation(updatePreferenceSettings(queryClient));
-
-	const mode: ThinkingDisplayMode = query.data?.thinking_display_mode || "auto";
-
-	return (
-		<div className="flex flex-col gap-2">
-			<h3 className="m-0 text-sm font-semibold text-content-primary">
-				Thinking Display
-			</h3>
-			<div className="flex items-center justify-between gap-4">
-				<p className="m-0 flex-1 text-xs text-content-secondary">
-					How thinking blocks should be displayed by default. 'Auto' fully
-					expands during streaming, then auto-collapses when done. 'Preview'
-					auto-expands with a height constraint during streaming. 'Always
-					Expanded' shows full content. 'Always Collapsed' keeps them collapsed.
-				</p>
-				<Select
-					value={mode}
-					disabled={query.isLoading || !query.data}
-					onValueChange={(value: string) => {
-						if (!query.data) return;
-						mutation.mutate({
-							...query.data,
-							thinking_display_mode: value as ThinkingDisplayMode,
-						});
-					}}
-				>
-					<SelectTrigger
-						className="w-44 shrink-0"
-						aria-label="Thinking display mode"
-					>
-						<SelectValue />
-					</SelectTrigger>
-					<SelectContent>
-						{options.map((opt) => (
-							<SelectItem key={opt.value} value={opt.value}>
-								{opt.label}
-							</SelectItem>
-						))}
-					</SelectContent>
-				</Select>
-			</div>
-			{mutation.isError && (
-				<p className="m-0 text-xs text-content-destructive">
-					Failed to save your thinking display preference.
-				</p>
-			)}
-		</div>
-	);
-};

site/src/pages/UserSettingsPage/NotificationsPage/NotificationsPage.stories.tsx

@@ -215,6 +215,7 @@ export const EnablingTaskNotificationClearsAlertDismissal: Story = {
 				data: {
 					task_notification_alert_dismissed: true,
 					thinking_display_mode: "auto" as const,
+					code_diff_display_mode: "auto" as const,
 				},
 			},
 		],
@@ -238,6 +239,7 @@ export const EnablingTaskNotificationClearsAlertDismissal: Story = {
 		).mockResolvedValue({
 			task_notification_alert_dismissed: false,
 			thinking_display_mode: "auto",
+			code_diff_display_mode: "auto",
 		});
 
 		await step("Enable Task Idle notification", async () => {