fix: Show experiment values in settings UI for compressionThreshold (#16267)

Co-authored-by: Vedant Mahajan <vedant.04.mahajan@gmail.com>

packages/cli/src/ui/components/SettingsDialog.tsx

@@ -29,7 +29,7 @@ import {
   isDefaultValue,
   requiresRestart,
   getRestartRequiredFromModified,
-  getDefaultValue,
+  getEffectiveDefaultValue,
   setPendingSettingValueAny,
   getNestedValue,
   getEffectiveValue,
@@ -743,7 +743,10 @@ export function SettingsDialog({
           // Ctrl+C or Ctrl+L: Clear current setting and reset to default
           const currentSetting = items[activeSettingIndex];
           if (currentSetting) {
-            const defaultValue = getDefaultValue(currentSetting.value);
+            const defaultValue = getEffectiveDefaultValue(
+              currentSetting.value,
+              config,
+            );
             const defType = currentSetting.type;
             if (defType === 'boolean') {
               const booleanDefaultValue =
@@ -963,7 +966,10 @@ export function SettingsDialog({
                 const path = item.value.split('.');
                 const currentValue = getNestedValue(pendingSettings, path);
 
-                const defaultValue = getDefaultValue(item.value);
+                const defaultValue = getEffectiveDefaultValue(
+                  item.value,
+                  config,
+                );
 
                 if (currentValue !== undefined && currentValue !== null) {
                   displayValue = String(currentValue);

packages/cli/src/utils/settingsUtils.ts

@@ -16,6 +16,8 @@ import type {
   SettingsValue,
 } from '../config/settingsSchema.js';
 import { getSettingsSchema } from '../config/settingsSchema.js';
+import type { Config } from '@google/gemini-cli-core';
+import { ExperimentFlags } from '@google/gemini-cli-core';
 
 // The schema is now nested, but many parts of the UI and logic work better
 // with a flattened structure and dot-notation keys. This section flattens the
@@ -96,6 +98,28 @@ export function getDefaultValue(key: string): SettingsValue {
   return getFlattenedSchema()[key]?.default;
 }
 
+/**
+ * Get the effective default value for a setting, checking experiment values when available.
+ * For settings like compressionThreshold, this will return the experiment value if set,
+ * otherwise falls back to the schema default.
+ */
+export function getEffectiveDefaultValue(
+  key: string,
+  config?: Config,
+): SettingsValue {
+  if (key === 'model.compressionThreshold' && config) {
+    const experiments = config.getExperiments();
+    const experimentValue =
+      experiments?.flags[ExperimentFlags.CONTEXT_COMPRESSION_THRESHOLD]
+        ?.floatValue;
+    if (experimentValue !== undefined && experimentValue !== 0) {
+      return experimentValue;
+    }
+  }
+
+  return getDefaultValue(key);
+}
+
 /**
  * Get all setting keys that require restart
  */

packages/core/index.ts

@@ -49,4 +49,5 @@ export * from './src/utils/googleQuotaErrors.js';
 export type { GoogleApiError } from './src/utils/googleErrors.js';
 export { getCodeAssistServer } from './src/code_assist/codeAssist.js';
 export { getExperiments } from './src/code_assist/experiments/experiments.js';
+export { ExperimentFlags } from './src/code_assist/experiments/flagNames.js';
 export { getErrorStatus, ModelNotFoundError } from './src/utils/httpErrors.js';

packages/core/src/config/config.ts

@@ -1585,8 +1585,6 @@ export class Config {
       return this.compressionThreshold;
     }
 
-    await this.ensureExperimentsLoaded();
-
     const remoteThreshold =
       this.experiments?.flags[ExperimentFlags.CONTEXT_COMPRESSION_THRESHOLD]
         ?.floatValue;