refactor: implement session synchronizer interfaces and logic for multiple providers

server/src/modules/ai-runtime/providers/base/abstract.provider.ts

@@ -1,6 +1,7 @@
 import type {
   IProvider,
   IProviderMcpRuntime,
+  IProviderSessionSynchronizerRuntime,
   IProviderSkillsRuntime,
   MutableProviderSession,
   ProviderCapabilities,
@@ -23,6 +24,7 @@ export abstract class AbstractProvider implements IProvider {
   readonly capabilities: ProviderCapabilities;
   abstract readonly mcp: IProviderMcpRuntime;
   abstract readonly skills: IProviderSkillsRuntime;
+  abstract readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime;
 
   protected readonly sessions = new Map<string, MutableProviderSession>();
 

server/src/modules/ai-runtime/providers/claude/claude-session-synchronizer.runtime.ts

@@ -8,8 +8,8 @@ import {
   findFilesRecursivelyCreatedAfter,
   normalizeSessionName,
   readFileTimestamps,
-} from '@/modules/ai-runtime/session-indexers/session-indexer.utils.js';
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
+} from '@/modules/ai-runtime/providers/shared/session-synchronizer/session-synchronizer.utils.js';
+import type { IProviderSessionSynchronizerRuntime } from '@/modules/ai-runtime/types/index.js';
 
 type ParsedSession = {
   sessionId: string;
@@ -20,19 +20,19 @@ type ParsedSession = {
 /**
  * Session indexer for Claude transcript artifacts.
  */
-export class ClaudeSessionIndexer implements ISessionIndexer {
-  readonly provider = 'claude' as const;
+export class ClaudeSessionSynchronizerRuntime implements IProviderSessionSynchronizerRuntime {
+  private readonly provider = 'claude' as const;
   private readonly claudeHome = path.join(os.homedir(), '.claude');
 
   /**
    * Scans ~/.claude projects and upserts discovered sessions into DB.
    */
-  async synchronize(lastScanAt: Date | null): Promise<number> {
+  async synchronize(since?: Date): Promise<number> {
     const nameMap = await buildLookupMap(path.join(this.claudeHome, 'history.jsonl'), 'sessionId', 'display');
     const files = await findFilesRecursivelyCreatedAfter(
       path.join(this.claudeHome, 'projects'),
       '.jsonl',
-      lastScanAt,
+      since ?? null,
     );
 
     let processed = 0;

server/src/modules/ai-runtime/providers/claude/claude.provider.ts

@@ -10,6 +10,7 @@ import { readFile } from 'node:fs/promises';
 import { BaseSdkProvider } from '@/modules/ai-runtime/providers/base/base-sdk.provider.js';
 import type {
   IProviderMcpRuntime,
+  IProviderSessionSynchronizerRuntime,
   IProviderSkillsRuntime,
   ProviderModel,
   ProviderSessionEvent,
@@ -18,6 +19,7 @@ import type {
 } from '@/modules/ai-runtime/types/index.js';
 import { ClaudeMcpRuntime } from '@/modules/ai-runtime/providers/claude/claude-mcp.runtime.js';
 import { ClaudeSkillsRuntime } from '@/modules/ai-runtime/providers/claude/claude-skills.runtime.js';
+import { ClaudeSessionSynchronizerRuntime } from '@/modules/ai-runtime/providers/claude/claude-session-synchronizer.runtime.js';
 
 type ClaudeExecutionInput = StartSessionInput & {
   sessionId: string;
@@ -75,6 +77,7 @@ const readString = (value: unknown): string | undefined => {
 export class ClaudeProvider extends BaseSdkProvider {
   readonly mcp: IProviderMcpRuntime = new ClaudeMcpRuntime();
   readonly skills: IProviderSkillsRuntime = new ClaudeSkillsRuntime();
+  readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime = new ClaudeSessionSynchronizerRuntime();
 
   constructor() {
     super('claude', {

server/src/modules/ai-runtime/providers/codex/codex-session-synchronizer.runtime.ts

@@ -8,8 +8,8 @@ import {
   findFilesRecursivelyCreatedAfter,
   normalizeSessionName,
   readFileTimestamps,
-} from '@/modules/ai-runtime/session-indexers/session-indexer.utils.js';
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
+} from '@/modules/ai-runtime/providers/shared/session-synchronizer/session-synchronizer.utils.js';
+import type { IProviderSessionSynchronizerRuntime } from '@/modules/ai-runtime/types/index.js';
 
 type ParsedSession = {
   sessionId: string;
@@ -20,19 +20,19 @@ type ParsedSession = {
 /**
  * Session indexer for Codex transcript artifacts.
  */
-export class CodexSessionIndexer implements ISessionIndexer {
-  readonly provider = 'codex' as const;
+export class CodexSessionSynchronizerRuntime implements IProviderSessionSynchronizerRuntime {
+  private readonly provider = 'codex' as const;
   private readonly codexHome = path.join(os.homedir(), '.codex');
 
   /**
    * Scans ~/.codex sessions and upserts discovered sessions into DB.
    */
-  async synchronize(lastScanAt: Date | null): Promise<number> {
+  async synchronize(since?: Date): Promise<number> {
     const nameMap = await buildLookupMap(path.join(this.codexHome, 'session_index.jsonl'), 'id', 'thread_name');
     const files = await findFilesRecursivelyCreatedAfter(
       path.join(this.codexHome, 'sessions'),
       '.jsonl',
-      lastScanAt,
+      since ?? null,
     );
 
     let processed = 0;

server/src/modules/ai-runtime/providers/codex/codex.provider.ts

@@ -5,6 +5,7 @@ import { readFile } from 'node:fs/promises';
 import { BaseSdkProvider } from '@/modules/ai-runtime/providers/base/base-sdk.provider.js';
 import type {
   IProviderMcpRuntime,
+  IProviderSessionSynchronizerRuntime,
   IProviderSkillsRuntime,
   ProviderModel,
   ProviderSessionEvent,
@@ -12,6 +13,7 @@ import type {
 } from '@/modules/ai-runtime/types/index.js';
 import { CodexMcpRuntime } from '@/modules/ai-runtime/providers/codex/codex-mcp.runtime.js';
 import { CodexSkillsRuntime } from '@/modules/ai-runtime/providers/codex/codex-skills.runtime.js';
+import { CodexSessionSynchronizerRuntime } from '@/modules/ai-runtime/providers/codex/codex-session-synchronizer.runtime.js';
 import { AppError } from '@/shared/utils/app-error.js';
 
 type CodexExecutionInput = StartSessionInput & {
@@ -67,6 +69,7 @@ type CodexSdkModule = {
 export class CodexProvider extends BaseSdkProvider {
   readonly mcp: IProviderMcpRuntime = new CodexMcpRuntime();
   readonly skills: IProviderSkillsRuntime = new CodexSkillsRuntime();
+  readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime = new CodexSessionSynchronizerRuntime();
 
   private codexClientPromise: Promise<CodexSdkClient> | null = null;
 

server/src/modules/ai-runtime/providers/cursor/cursor-session-synchronizer.runtime.ts

@@ -11,8 +11,8 @@ import {
   listDirectoryEntriesSafe,
   normalizeSessionName,
   readFileTimestamps,
-} from '@/modules/ai-runtime/session-indexers/session-indexer.utils.js';
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
+} from '@/modules/ai-runtime/providers/shared/session-synchronizer/session-synchronizer.utils.js';
+import type { IProviderSessionSynchronizerRuntime } from '@/modules/ai-runtime/types/index.js';
 
 type ParsedSession = {
   sessionId: string;
@@ -23,14 +23,14 @@ type ParsedSession = {
 /**
  * Session indexer for Cursor transcript artifacts.
  */
-export class CursorSessionIndexer implements ISessionIndexer {
-  readonly provider = 'cursor' as const;
+export class CursorSessionSynchronizerRuntime implements IProviderSessionSynchronizerRuntime {
+  private readonly provider = 'cursor' as const;
   private readonly cursorHome = path.join(os.homedir(), '.cursor');
 
   /**
    * Scans Cursor chats and upserts discovered sessions into DB.
    */
-  async synchronize(lastScanAt: Date | null): Promise<number> {
+  async synchronize(since?: Date): Promise<number> {
     const projectsDir = path.join(this.cursorHome, 'projects');
     const projectEntries = await listDirectoryEntriesSafe(projectsDir);
     const seenWorkspacePaths = new Set<string>();
@@ -50,7 +50,7 @@ export class CursorSessionIndexer implements ISessionIndexer {
       seenWorkspacePaths.add(workspacePath);
       const workspaceHash = this.md5(workspacePath);
       const chatsDir = path.join(this.cursorHome, 'chats', workspaceHash);
-      const files = await findFilesRecursivelyCreatedAfter(chatsDir, '.jsonl', lastScanAt);
+      const files = await findFilesRecursivelyCreatedAfter(chatsDir, '.jsonl', since ?? null);
 
       for (const filePath of files) {
         const parsed = await this.processSessionFile(filePath);

server/src/modules/ai-runtime/providers/cursor/cursor.provider.ts

@@ -1,12 +1,14 @@
 import { BaseCliProvider } from '@/modules/ai-runtime/providers/base/base-cli.provider.js';
 import type {
   IProviderMcpRuntime,
+  IProviderSessionSynchronizerRuntime,
   IProviderSkillsRuntime,
   ProviderModel,
   StartSessionInput,
 } from '@/modules/ai-runtime/types/index.js';
 import { CursorMcpRuntime } from '@/modules/ai-runtime/providers/cursor/cursor-mcp.runtime.js';
 import { CursorSkillsRuntime } from '@/modules/ai-runtime/providers/cursor/cursor-skills.runtime.js';
+import { CursorSessionSynchronizerRuntime } from '@/modules/ai-runtime/providers/cursor/cursor-session-synchronizer.runtime.js';
 
 type CursorExecutionInput = StartSessionInput & {
   sessionId: string;
@@ -23,6 +25,7 @@ const ANSI_REGEX =
 export class CursorProvider extends BaseCliProvider {
   readonly mcp: IProviderMcpRuntime = new CursorMcpRuntime();
   readonly skills: IProviderSkillsRuntime = new CursorSkillsRuntime();
+  readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime = new CursorSessionSynchronizerRuntime();
 
   constructor() {
     super('cursor', {

server/src/modules/ai-runtime/providers/gemini/gemini-session-synchronizer.runtime.ts

@@ -7,8 +7,8 @@ import {
   findFilesRecursivelyCreatedAfter,
   normalizeSessionName,
   readFileTimestamps,
-} from '@/modules/ai-runtime/session-indexers/session-indexer.utils.js';
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
+} from '@/modules/ai-runtime/providers/shared/session-synchronizer/session-synchronizer.utils.js';
+import type { IProviderSessionSynchronizerRuntime } from '@/modules/ai-runtime/types/index.js';
 
 type ParsedSession = {
   sessionId: string;
@@ -19,23 +19,23 @@ type ParsedSession = {
 /**
  * Session indexer for Gemini transcript artifacts.
  */
-export class GeminiSessionIndexer implements ISessionIndexer {
-  readonly provider = 'gemini' as const;
+export class GeminiSessionSynchronizerRuntime implements IProviderSessionSynchronizerRuntime {
+  private readonly provider = 'gemini' as const;
   private readonly geminiHome = path.join(os.homedir(), '.gemini');
 
   /**
    * Scans Gemini session JSON files and upserts discovered sessions into DB.
    */
-  async synchronize(lastScanAt: Date | null): Promise<number> {
+  async synchronize(since?: Date): Promise<number> {
     const legacySessionFiles = await findFilesRecursivelyCreatedAfter(
       path.join(this.geminiHome, 'sessions'),
       '.json',
-      lastScanAt,
+      since ?? null,
     );
     const tempFiles = await findFilesRecursivelyCreatedAfter(
       path.join(this.geminiHome, 'tmp'),
       '.json',
-      lastScanAt,
+      since ?? null,
     );
     const files = [...legacySessionFiles, ...tempFiles];
 

server/src/modules/ai-runtime/providers/gemini/gemini.provider.ts

@@ -1,12 +1,14 @@
 import { BaseCliProvider } from '@/modules/ai-runtime/providers/base/base-cli.provider.js';
 import type {
   IProviderMcpRuntime,
+  IProviderSessionSynchronizerRuntime,
   IProviderSkillsRuntime,
   ProviderModel,
   StartSessionInput,
 } from '@/modules/ai-runtime/types/index.js';
 import { GeminiMcpRuntime } from '@/modules/ai-runtime/providers/gemini/gemini-mcp.runtime.js';
 import { GeminiSkillsRuntime } from '@/modules/ai-runtime/providers/gemini/gemini-skills.runtime.js';
+import { GeminiSessionSynchronizerRuntime } from '@/modules/ai-runtime/providers/gemini/gemini-session-synchronizer.runtime.js';
 
 type GeminiExecutionInput = StartSessionInput & {
   sessionId: string;
@@ -31,6 +33,7 @@ const GEMINI_MODELS: ProviderModel[] = [
 export class GeminiProvider extends BaseCliProvider {
   readonly mcp: IProviderMcpRuntime = new GeminiMcpRuntime();
   readonly skills: IProviderSkillsRuntime = new GeminiSkillsRuntime();
+  readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime = new GeminiSessionSynchronizerRuntime();
 
   constructor() {
     super('gemini', {

server/src/modules/ai-runtime/services/sessions.service.ts

@@ -5,7 +5,7 @@ import { scanStateDb } from '@/shared/database/repositories/scan-state.db.js';
 import { sessionsDb } from '@/shared/database/repositories/sessions.db.js';
 import type { LLMProvider } from '@/shared/types/app.js';
 import { AppError } from '@/shared/utils/app-error.js';
-import { sessionIndexers } from '@/modules/ai-runtime/session-indexers/index.js';
+import { llmProviderRegistry } from '@/modules/ai-runtime/ai-runtime.registry.js';
 import { llmMessagesUnifier, type UnifiedChatMessage } from '@/modules/ai-runtime/services/messages-unifier.service.js';
 
 type SyncResult = {
@@ -119,12 +119,11 @@ export const llmSessionsService = {
     };
     const failures: string[] = [];
 
-    const results = await Promise.allSettled(
-      sessionIndexers.map(async (indexer) => ({
-        provider: indexer.provider,
-        processed: await indexer.synchronize(lastScanAt),
-      })),
-    );
+    // Provider-specific session indexers used by the sync orchestrator.
+    const results = await Promise.allSettled(llmProviderRegistry.listProviders().map(async (provider) => ({
+      provider: provider.id,
+      processed: await provider.sessionSynchronizer.synchronize(lastScanAt ?? undefined),
+    })));
 
     for (const result of results) {
       if (result.status === 'fulfilled') {
@@ -151,19 +150,15 @@ export const llmSessionsService = {
     provider: LLMProvider,
     filePath: string,
   ): Promise<{ provider: LLMProvider; indexed: boolean }> {
-    const indexer = sessionIndexers.find((entry) => entry.provider === provider);
-    if (!indexer) {
+    const resolvedProvider = llmProviderRegistry.listProviders().find((entry) => entry.id === provider);
+    if (!resolvedProvider) {
       throw new AppError(`No session indexer registered for provider "${provider}".`, {
         code: 'SESSION_INDEXER_NOT_FOUND',
         statusCode: 500,
       });
     }
 
-    if (!indexer.synchronizeFile) {
-      return { provider, indexed: false };
-    }
-
-    const indexed = await indexer.synchronizeFile(filePath);
+    const indexed = await resolvedProvider.sessionSynchronizer.synchronizeFile(filePath);
     return { provider, indexed };
   },
 

server/src/modules/ai-runtime/session-indexers/index.ts

@@ -1,15 +0,0 @@
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
-import { ClaudeSessionIndexer } from '@/modules/ai-runtime/session-indexers/claude.session-indexer.js';
-import { CodexSessionIndexer } from '@/modules/ai-runtime/session-indexers/codex.session-indexer.js';
-import { CursorSessionIndexer } from '@/modules/ai-runtime/session-indexers/cursor.session-indexer.js';
-import { GeminiSessionIndexer } from '@/modules/ai-runtime/session-indexers/gemini.session-indexer.js';
-
-/**
- * Provider-specific session indexers used by the sync orchestrator.
- */
-export const sessionIndexers: ISessionIndexer[] = [
-  new ClaudeSessionIndexer(),
-  new CodexSessionIndexer(),
-  new CursorSessionIndexer(),
-  new GeminiSessionIndexer(),
-];

server/src/modules/ai-runtime/tests/sessions.test.ts

@@ -7,10 +7,9 @@ import test from 'node:test';
 import { AppError } from '@/shared/utils/app-error.js';
 import { scanStateDb } from '@/shared/database/repositories/scan-state.db.js';
 import { sessionsDb } from '@/shared/database/repositories/sessions.db.js';
+import { llmProviderRegistry } from '@/modules/ai-runtime/ai-runtime.registry.js';
 import { llmSessionsService } from '@/modules/ai-runtime/services/sessions.service.js';
-import { sessionIndexers } from '@/modules/ai-runtime/session-indexers/index.js';
 import { conversationSearchService } from '@/modules/conversations/conversation-search.service.js';
-import type { ISessionIndexer } from '@/modules/ai-runtime/session-indexers/session-indexer.interface.js';
 
 const patchMethod = <T extends object, K extends keyof T>(target: T, key: K, replacement: T[K]) => {
   const original = target[key];
@@ -20,14 +19,6 @@ const patchMethod = <T extends object, K extends keyof T>(target: T, key: K, rep
   };
 };
 
-const patchIndexers = (nextIndexers: ISessionIndexer[]) => {
-  const originalIndexers = [...sessionIndexers];
-  sessionIndexers.splice(0, sessionIndexers.length, ...nextIndexers);
-  return () => {
-    sessionIndexers.splice(0, sessionIndexers.length, ...originalIndexers);
-  };
-};
-
 // This test covers multi-provider synchronization orchestration and failure aggregation.
 test('llmSessionsService.synchronizeSessions aggregates processed counts and failures', { concurrency: false }, async () => {
   let updateLastScannedAtCalls = 0;
@@ -35,20 +26,24 @@ test('llmSessionsService.synchronizeSessions aggregates processed counts and fai
   const restoreUpdateScanDate = patchMethod(scanStateDb, 'updateLastScannedAt', () => {
     updateLastScannedAtCalls += 1;
   });
-  const restoreIndexers = patchIndexers([
+  const restoreProviders = patchMethod(llmProviderRegistry, 'listProviders', () => ([
     {
-      provider: 'claude',
-      async synchronize() {
-        return 3;
+      id: 'claude',
+      sessionSynchronizer: {
+        async synchronize() {
+          return 3;
+        },
       },
     },
     {
-      provider: 'codex',
-      async synchronize() {
-        throw new Error('codex index failed');
+      id: 'codex',
+      sessionSynchronizer: {
+        async synchronize() {
+          throw new Error('codex index failed');
+        },
       },
     },
-  ]);
+  ] as any));
 
   try {
     const result = await llmSessionsService.synchronizeSessions();
@@ -60,7 +55,7 @@ test('llmSessionsService.synchronizeSessions aggregates processed counts and fai
     assert.equal(result.failures[0], 'codex index failed');
     assert.equal(updateLastScannedAtCalls, 1);
   } finally {
-    restoreIndexers();
+    restoreProviders();
     restoreUpdateScanDate();
     restoreScanDate();
   }
@@ -70,19 +65,21 @@ test('llmSessionsService.synchronizeSessions aggregates processed counts and fai
 test('llmSessionsService.synchronizeProviderFile delegates to provider indexer file sync', { concurrency: false }, async () => {
   let synchronizeCalls = 0;
   let synchronizeFilePath: string | null = null;
-  const restoreIndexers = patchIndexers([
+  const restoreProviders = patchMethod(llmProviderRegistry, 'listProviders', () => ([
     {
-      provider: 'claude',
-      async synchronize() {
-        synchronizeCalls += 1;
-        return 0;
-      },
-      async synchronizeFile(filePath: string) {
-        synchronizeFilePath = filePath;
-        return true;
+      id: 'claude',
+      sessionSynchronizer: {
+        async synchronize() {
+          synchronizeCalls += 1;
+          return 0;
+        },
+        async synchronizeFile(filePath: string) {
+          synchronizeFilePath = filePath;
+          return true;
+        },
       },
     },
-  ]);
+  ] as any));
 
   try {
     const result = await llmSessionsService.synchronizeProviderFile('claude', '/tmp/claude-session.jsonl');
@@ -91,7 +88,7 @@ test('llmSessionsService.synchronizeProviderFile delegates to provider indexer f
     assert.equal(synchronizeFilePath, '/tmp/claude-session.jsonl');
     assert.equal(synchronizeCalls, 0);
   } finally {
-    restoreIndexers();
+    restoreProviders();
   }
 });
 

server/src/modules/ai-runtime/types/index.ts

@@ -1,3 +1,4 @@
 export * from '@/modules/ai-runtime/types/provider.types.js';
 export * from '@/modules/ai-runtime/types/mcp.types.js';
 export * from '@/modules/ai-runtime/types/skills.types.js';
+export * from '@/modules/ai-runtime/types/session-synchronizer.types.js';

server/src/modules/ai-runtime/types/provider.types.ts

@@ -1,6 +1,7 @@
 import type { LLMProvider } from '@/shared/types/app.js';
 import type { IProviderMcpRuntime } from '@/modules/ai-runtime/types/mcp.types.js';
 import type { IProviderSkillsRuntime } from '@/modules/ai-runtime/types/skills.types.js';
+import type { IProviderSessionSynchronizerRuntime } from '@/modules/ai-runtime/types/session-synchronizer.types.js';
 
 export type ProviderExecutionFamily = 'sdk' | 'cli';
 
@@ -78,6 +79,7 @@ export interface IProvider {
   readonly capabilities: ProviderCapabilities;
   readonly mcp: IProviderMcpRuntime;
   readonly skills: IProviderSkillsRuntime;
+  readonly sessionSynchronizer: IProviderSessionSynchronizerRuntime;
 
   listModels(): Promise<ProviderModel[]>;
 

server/src/modules/ai-runtime/types/session-synchronizer.types.ts

@@ -1,18 +1,14 @@
-import type { LLMProvider } from '@/shared/types/app.js';
-
 /**
  * Contract for provider-specific session indexing logic.
  */
-export interface ISessionIndexer {
-  readonly provider: LLMProvider;
-
+export interface IProviderSessionSynchronizerRuntime {
   /**
    * Scans provider session artifacts and upserts discovered sessions into DB.
    */
-  synchronize(lastScanAt: Date | null): Promise<number>;
+  synchronize(since?: Date): Promise<number>;
 
   /**
    * Parses and upserts one provider artifact file without running a full directory scan.
    */
-  synchronizeFile?(filePath: string): Promise<boolean>;
+  synchronizeFile(filePath: string): Promise<boolean>;
 }