fix: seed default model on catalog import and gate MCP management

Seed default_model when unset after models.dev/registry import. Return
an empty plugin marketplace when no URL is configured. Reject MCP
management RPCs while the experimental flag is off.

Author: elkaix

packages/agent-core-v2/src/app/kosongConfig/modelsDevImportService.ts

@@ -16,7 +16,7 @@ import { IModelService, modelRecordProviderId, type ModelsSection } from '#/koso
 import { type ProviderConfig, type ProvidersSection } from '#/kosong/provider/provider';
 import { modelsDevProviderModels, resolveModelsDevImport } from './modelsDev';
 
-import { MODELS_SECTION, PROVIDERS_SECTION } from './configSection';
+import { DEFAULT_MODEL_SECTION, MODELS_SECTION, PROVIDERS_SECTION } from './configSection';
 import { ModelsDevImportErrors } from './errors';
 import { IKosongConfigService } from './kosongConfig';
 import {
@@ -86,6 +86,12 @@ export class ModelsDevImportService implements IModelsDevImportService {
     return this.enqueueWrite(() => this.doImportCustomRegistry(options));
   }
 
+  private async seedDefaultModelWhenUnset(config: IConfigService, alias: string): Promise<void> {
+    const current = config.inspect<string>(DEFAULT_MODEL_SECTION).userValue;
+    if (current !== undefined && current.trim() !== '') return;
+    await config.replace(DEFAULT_MODEL_SECTION, alias);
+  }
+
   private enqueueWrite<T>(task: () => Promise<T>): Promise<T> {
     const run = this.writeChain.then(task, task);
     this.writeChain = run.then(
@@ -165,6 +171,11 @@ export class ModelsDevImportService implements IModelsDevImportService {
     }
     await config.replace(MODELS_SECTION, nextModels);
 
+    const firstModel = models[0];
+    if (firstModel !== undefined) {
+      await this.seedDefaultModelWhenUnset(config, `${targetId}/${firstModel.id}`);
+    }
+
     await this.models.settled;
     const imported = await this.modelCatalog.getProvider(targetId);
     return { provider: imported, modelsImported: models.length };
@@ -239,6 +250,14 @@ export class ModelsDevImportService implements IModelsDevImportService {
     await config.replace(PROVIDERS_SECTION, applied.providers as ProvidersSection);
     await config.replace(MODELS_SECTION, (applied.models ?? {}) as ModelsSection);
 
+    const firstEntry = Object.values(entries)[0];
+    if (firstEntry !== undefined) {
+      const firstModelId = Object.keys(firstEntry.models)[0];
+      if (firstModelId !== undefined) {
+        await this.seedDefaultModelWhenUnset(config, `${firstEntry.id}/${firstModelId}`);
+      }
+    }
+
     await this.models.settled;
     const imported = [];
     for (const entry of Object.values(entries)) {

packages/agent-core-v2/src/app/mcpManagement/mcpManagementService.ts

@@ -6,6 +6,7 @@ import { Disposable } from '#/_base/di/lifecycle';
 import { LifecycleScope } from '#/app/scopes';
 import { ScopeActivation, registerScopedService } from '#/_base/di/scope';
 import { ILogService } from '#/_base/log/log';
+import { IFlagService } from '#/app/flag/flag';
 
 import { ErrorCodes, Error2 } from '#/errors';
 import { McpConnectionManager } from '#/mcpCore/connection-manager';
@@ -52,6 +53,7 @@ import {
   type McpServerTestResult,
   type McpServerTestTarget,
 } from './mcpManagement';
+import { MCP_MANAGEMENT_FLAG_ID } from './flag';
 
 const DEFAULT_AUTH_TIMEOUT_MS = 15 * 60_000;
 const AUTH_FLOW_IDLE_TIMEOUT_MS = 15 * 60_000;
@@ -76,15 +78,27 @@ export class McpManagementService extends Disposable implements IMcpManagementSe
     @IHostEnvironment private readonly hostEnvironment: IHostEnvironment,
     @IHostProcessService private readonly hostProcess: IHostProcessService,
     @ILogService private readonly log: ILogService,
+    @IFlagService private readonly flags: IFlagService,
   ) {
     super();
   }
 
+  private assertManagementEnabled(): void {
+    if (!this.flags.enabled(MCP_MANAGEMENT_FLAG_ID)) {
+      throw new Error2(
+        ErrorCodes.REQUEST_INVALID,
+        'MCP management is disabled; enable the mcp-management experimental flag',
+      );
+    }
+  }
+
   async listServers(query: McpRegistryQuery = {}): Promise<readonly McpManagedServer[]> {
+    this.assertManagementEnabled();
     return (await this.registry.list(query)).map(toManagedServer);
   }
 
   async getServer(name: string, query: McpRegistryQuery = {}): Promise<McpManagedServer> {
+    this.assertManagementEnabled();
     return toManagedServer(await this.registry.get(name, query));
   }
 

packages/agent-core-v2/test/app/mcpManagement/mcpManagement.test.ts

@@ -10,6 +10,7 @@ import { afterEach, beforeEach, describe, expect, it, vi, type Mock } from 'vite
 
 import { DisposableStore } from '#/_base/di/lifecycle';
 import { createServices } from '#/_base/di/test';
+import { IFlagService } from '#/app/flag/flag';
 import { ILogService } from '#/_base/log/log';
 import { IBootstrapService } from '#/app/bootstrap/bootstrap';
 import {
@@ -154,6 +155,9 @@ describe('McpManagementService', () => {
         });
         reg.definePartialInstance(IWorkspaceInstanceManager, { findContaining, getOrCreate });
         reg.defineInstance(ILogService, stubLog());
+        reg.definePartialInstance(IFlagService, {
+          enabled: () => true,
+        });
         reg.define(IMcpManagementService, McpManagementService);
       },
     });

packages/agent-gateway/src/routes/plugins.ts

@@ -124,11 +124,16 @@ export function registerPluginsRoutes(
       operationId: 'listPluginMarketplace',
     },
     async (req, reply) => {
+      const source = opts.marketplaceUrl().trim();
+      if (source.length === 0) {
+        reply.send(okEnvelope({ entries: [] }, req.id));
+        return;
+      }
       const fetchImpl = opts.fetchImpl ?? fetchWithTimeout;
       let read: { raw: string; location: MarketplaceLocation };
       try {
         read = await readPluginMarketplace({
-          source: opts.marketplaceUrl(),
+          source,
           workDir: process.cwd(),
           fetchImpl,
           sourceCheckoutLocation:

packages/agent-gateway/src/start.ts

@@ -439,14 +439,10 @@ export async function startServer(opts: ServerStartOptions): Promise<RunningServ
     guiStore,
     pluginMarketplaceUrl: (() => {
       const configured = opts.pluginMarketplaceUrl ?? process.env['PYTHINKER_CODE_PLUGIN_MARKETPLACE_URL'];
-      if (configured !== undefined) return () => configured;
-      return () =>
-        'https://code.pythinker.com/pythinker-code/plugins/marketplace.json';
+      if (configured !== undefined && configured.trim() !== '') return () => configured;
+      return () => '';
     })(),
-    pluginMarketplaceIsDefault:
-      opts.pluginMarketplaceUrl === undefined &&
-      (process.env['PYTHINKER_CODE_PLUGIN_MARKETPLACE_URL'] === undefined ||
-        process.env['PYTHINKER_CODE_PLUGIN_MARKETPLACE_FROM_DEV_SERVER'] === '1'),
+    pluginMarketplaceIsDefault: false,
     remoteControl: {
       service: remoteControlManager,
       staticEnableError: