feat(core): use experiment flags for default fetch timeouts (#24261)

packages/core/src/config/config.test.ts

@@ -644,6 +644,58 @@ describe('Server Config (config.ts)', () => {
         },
       );
     });
+
+    describe('getRequestTimeoutMs', () => {
+      it('should return undefined if the flag is not set', () => {
+        const config = new Config(baseParams);
+        expect(config.getRequestTimeoutMs()).toBeUndefined();
+      });
+
+      it('should return timeout in milliseconds if flag is set', () => {
+        const config = new Config({
+          ...baseParams,
+          experiments: {
+            flags: {
+              [ExperimentFlags.DEFAULT_REQUEST_TIMEOUT]: {
+                intValue: '30',
+              },
+            },
+            experimentIds: [],
+          },
+        } as unknown as ConfigParameters);
+        expect(config.getRequestTimeoutMs()).toBe(30000);
+      });
+
+      it('should return undefined if intValue is not a valid integer', () => {
+        const config = new Config({
+          ...baseParams,
+          experiments: {
+            flags: {
+              [ExperimentFlags.DEFAULT_REQUEST_TIMEOUT]: {
+                intValue: 'abc',
+              },
+            },
+            experimentIds: [],
+          },
+        } as unknown as ConfigParameters);
+        expect(config.getRequestTimeoutMs()).toBeUndefined();
+      });
+
+      it('should return undefined if intValue is negative', () => {
+        const config = new Config({
+          ...baseParams,
+          experiments: {
+            flags: {
+              [ExperimentFlags.DEFAULT_REQUEST_TIMEOUT]: {
+                intValue: '-10',
+              },
+            },
+            experimentIds: [],
+          },
+        } as unknown as ConfigParameters);
+        expect(config.getRequestTimeoutMs()).toBeUndefined();
+      });
+    });
   });
 
   describe('refreshAuth', () => {
@@ -2078,8 +2130,18 @@ describe('BaseLlmClient Lifecycle', () => {
     usageStatisticsEnabled: false,
   };
 
+  it('should throw an error if getBaseLlmClient is called before experiments have been fetched', () => {
+    const config = new Config(baseParams);
+    // By default on a new Config instance, experiments are undefined
+    expect(() => config.getBaseLlmClient()).toThrow(
+      'BaseLlmClient not initialized. Ensure experiments have been fetched and configuration is ready.',
+    );
+  });
+
   it('should throw an error if getBaseLlmClient is called before refreshAuth', () => {
     const config = new Config(baseParams);
+    // Explicitly set experiments to avoid triggering the new missing-experiments error
+    config.setExperiments({ flags: {}, experimentIds: [] });
     expect(() => config.getBaseLlmClient()).toThrow(
       'BaseLlmClient not initialized. Ensure authentication has occurred and ContentGenerator is ready.',
     );

packages/core/src/config/config.ts

@@ -160,7 +160,7 @@ import {
 } from '../code_assist/experiments/experiments.js';
 import { AgentRegistry } from '../agents/registry.js';
 import { AcknowledgedAgentsService } from '../agents/acknowledgedAgents.js';
-import { setGlobalProxy } from '../utils/fetch.js';
+import { setGlobalProxy, updateGlobalFetchTimeouts } from '../utils/fetch.js';
 import { SubagentTool } from '../agents/subagent-tool.js';
 import { ExperimentFlags } from '../code_assist/experiments/flagNames.js';
 import { debugLogger } from '../utils/debugLogger.js';
@@ -1548,9 +1548,6 @@ export class Config implements McpContext, AgentLoopContext {
     // Only assign to instance properties after successful initialization
     this.contentGeneratorConfig = newContentGeneratorConfig;
 
-    // Initialize BaseLlmClient now that the ContentGenerator is available
-    this.baseLlmClient = new BaseLlmClient(this.contentGenerator, this);
-
     const codeAssistServer = getCodeAssistServer(this);
     const quotaPromise = codeAssistServer?.projectId
       ? this.refreshUserQuota()
@@ -1566,6 +1563,17 @@ export class Config implements McpContext, AgentLoopContext {
         return undefined;
       });
 
+    // Fetch experiments and update timeouts before continuing initialization
+    const experiments = await this.experimentsPromise;
+
+    const requestTimeoutMs = this.getRequestTimeoutMs();
+    if (requestTimeoutMs !== undefined) {
+      updateGlobalFetchTimeouts(requestTimeoutMs);
+    }
+
+    // Initialize BaseLlmClient now that the ContentGenerator and experiments are available
+    this.baseLlmClient = new BaseLlmClient(this.contentGenerator, this);
+
     await quotaPromise;
 
     const authType = this.contentGeneratorConfig.authType;
@@ -1585,9 +1593,6 @@ export class Config implements McpContext, AgentLoopContext {
       this.setModel(DEFAULT_GEMINI_MODEL_AUTO);
     }
 
-    // Fetch admin controls
-    const experiments = await this.experimentsPromise;
-
     const adminControlsEnabled =
       experiments?.flags[ExperimentFlags.ENABLE_ADMIN_CONTROLS]?.boolValue ??
       false;
@@ -1633,6 +1638,11 @@ export class Config implements McpContext, AgentLoopContext {
   getBaseLlmClient(): BaseLlmClient {
     if (!this.baseLlmClient) {
       // Handle cases where initialization might be deferred or authentication failed
+      if (!this.experiments) {
+        throw new Error(
+          'BaseLlmClient not initialized. Ensure experiments have been fetched and configuration is ready.',
+        );
+      }
       if (this.contentGenerator) {
         this.baseLlmClient = new BaseLlmClient(
           this.getContentGenerator(),
@@ -3153,6 +3163,21 @@ export class Config implements McpContext, AgentLoopContext {
     );
   }
 
+  /**
+   * Returns the configured default request timeout in milliseconds.
+   */
+  getRequestTimeoutMs(): number | undefined {
+    const flag =
+      this.experiments?.flags?.[ExperimentFlags.DEFAULT_REQUEST_TIMEOUT];
+    if (flag?.intValue !== undefined) {
+      const seconds = parseInt(flag.intValue, 10);
+      if (Number.isInteger(seconds) && seconds >= 0) {
+        return seconds * 1000; // Convert seconds to milliseconds
+      }
+    }
+    return undefined;
+  }
+
   /**
    * Returns whether Gemini 3.1 Flash Lite has been launched.
    *