feat(analytics): add top tools and topics to session analytics

src/session/index.ts

@@ -1,5 +1,11 @@
 export { SessionStore, parseDuration } from './store.js';
-export type { SessionAnalyticsSnapshot, SessionDailyAnalyticsRow, SessionTopAnalyticsRow } from './store.js';
+export type {
+  SessionAnalyticsSnapshot,
+  SessionDailyAnalyticsRow,
+  SessionTopAnalyticsRow,
+  SessionTopToolAnalyticsRow,
+  SessionTopTopicAnalyticsRow,
+} from './store.js';
 export { SessionManager, ManagedSession, type Session } from './manager.js';
 export { SessionIndexer, tokenize } from './indexer.js';
 export type { HistoryMetadata, HistoryIndexerConfig } from './indexer.js';

src/session/store.test.ts

@@ -79,10 +79,13 @@ describe('SessionStore', () => {
     const nowSec = Math.floor(nowMs / 1000);
     const yesterdaySec = nowSec - 86_400;
 
-    store.addMessage('session-a', { role: 'user', content: 'A1', timestamp: nowMs });
-    store.addMessage('session-a', { role: 'assistant', content: 'A2', timestamp: nowMs + 1000 });
-    store.addMessage('session-b', { role: 'user', content: 'B1', timestamp: nowMs });
-    store.addMessage('session-c', { role: 'user', content: 'C1', timestamp: yesterdaySec * 1000 });
+    store.addMessage('session-a', { role: 'user', content: 'A1', timestamp: nowMs }, { keywords: ['kubernetes'], topics: ['kubernetes'] });
+    store.addMessage('session-a', { role: 'assistant', content: 'A2', timestamp: nowMs + 1000 }, { keywords: ['deploy'], topics: ['deploy'] });
+    store.addMessage('session-b', { role: 'user', content: 'B1', timestamp: nowMs }, { keywords: ['kubernetes'], topics: ['kubernetes'] });
+    store.addMessage('session-c', { role: 'user', content: 'C1', timestamp: yesterdaySec * 1000 }, { keywords: ['incident'], topics: ['incident'] });
+    store.recordToolExecution('session-a', 'web.search', true, nowSec);
+    store.recordToolExecution('session-a', 'web.search', true, nowSec);
+    store.recordToolExecution('session-b', 'file.read', true, nowSec);
 
     const snapshot = store.getSessionAnalytics({
       sinceTimestamp: yesterdaySec,
@@ -94,6 +97,14 @@ describe('SessionStore', () => {
     expect(snapshot.averageMessagesPerSession).toBeCloseTo(1.33, 2);
     expect(snapshot.topSessions).toHaveLength(2);
     expect(snapshot.topSessions[0]?.sessionId).toBe('session-a');
+    expect(snapshot.topTools).toEqual([
+      { toolName: 'web.search', executions: 2 },
+      { toolName: 'file.read', executions: 1 },
+    ]);
+    expect(snapshot.topTopics).toEqual([
+      { topic: 'kubernetes', occurrences: 2 },
+      { topic: 'deploy', occurrences: 1 },
+    ]);
     expect(snapshot.daily.length).toBeGreaterThan(0);
   });
 

src/session/store.ts

@@ -24,9 +24,21 @@ export interface SessionTopAnalyticsRow {
   lastActivity: number;
 }
 
+export interface SessionTopToolAnalyticsRow {
+  toolName: string;
+  executions: number;
+}
+
+export interface SessionTopTopicAnalyticsRow {
+  topic: string;
+  occurrences: number;
+}
+
 export interface SessionAnalyticsSnapshot {
   daily: SessionDailyAnalyticsRow[];
   topSessions: SessionTopAnalyticsRow[];
+  topTools: SessionTopToolAnalyticsRow[];
+  topTopics: SessionTopTopicAnalyticsRow[];
   averageMessagesPerSession: number;
   totalSessions: number;
   totalMessages: number;
@@ -64,6 +76,15 @@ export class SessionStore {
         PRIMARY KEY (session_id, key)
       );
       CREATE INDEX IF NOT EXISTS idx_session_config_session ON session_config(session_id);
+      CREATE TABLE IF NOT EXISTS tool_executions (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        session_id TEXT NOT NULL,
+        tool_name TEXT NOT NULL,
+        created_at INTEGER NOT NULL DEFAULT (unixepoch()),
+        success INTEGER NOT NULL
+      );
+      CREATE INDEX IF NOT EXISTS idx_tool_executions_session ON tool_executions(session_id);
+      CREATE INDEX IF NOT EXISTS idx_tool_executions_created_at ON tool_executions(created_at);
     `);
 
     const messageColumns = this.db.prepare('PRAGMA table_info(messages)').all() as Array<{ name: string }>;
@@ -117,6 +138,7 @@ export class SessionStore {
     const transaction = this.db.transaction(() => {
       this.db.prepare('DELETE FROM messages WHERE session_id = ?').run(sessionId);
       this.db.prepare('DELETE FROM session_config WHERE session_id = ?').run(sessionId);
+      this.db.prepare('DELETE FROM tool_executions WHERE session_id = ?').run(sessionId);
     });
     transaction();
   }
@@ -139,10 +161,12 @@ export class SessionStore {
 
     const deleteMessages = this.db.prepare('DELETE FROM messages WHERE session_id = ?');
     const deleteConfig = this.db.prepare('DELETE FROM session_config WHERE session_id = ?');
+    const deleteToolExecutions = this.db.prepare('DELETE FROM tool_executions WHERE session_id = ?');
     const transaction = this.db.transaction(() => {
       for (const { session_id } of stale) {
         deleteMessages.run(session_id);
         deleteConfig.run(session_id);
+        deleteToolExecutions.run(session_id);
       }
     });
     transaction();
@@ -288,6 +312,12 @@ export class SessionStore {
     this.db.prepare('UPDATE messages SET metadata = ? WHERE id = ?').run(JSON.stringify(metadata), messageId);
   }
 
+  recordToolExecution(sessionId: string, toolName: string, success: boolean, createdAtSeconds?: number): void {
+    this.db.prepare(
+      'INSERT INTO tool_executions (session_id, tool_name, created_at, success) VALUES (?, ?, ?, ?)',
+    ).run(sessionId, toolName, createdAtSeconds ?? Math.floor(Date.now() / 1000), success ? 1 : 0);
+  }
+
   getSessionAnalytics(opts: { sinceTimestamp: number; topLimit?: number }): SessionAnalyticsSnapshot {
     const since = opts.sinceTimestamp;
     const topLimit = opts.topLimit ?? 10;
@@ -315,6 +345,17 @@ export class SessionStore {
       LIMIT ?
     `).all(since, topLimit) as Array<{ session_id: string; messages: number; last_activity: number }>;
 
+    const topToolsRows = this.db.prepare(`
+      SELECT
+        tool_name,
+        COUNT(*) AS executions
+      FROM tool_executions
+      WHERE created_at >= ?
+      GROUP BY tool_name
+      ORDER BY executions DESC, tool_name ASC
+      LIMIT ?
+    `).all(since, topLimit) as Array<{ tool_name: string; executions: number }>;
+
     const totalMessagesRow = this.db.prepare(`
       SELECT COUNT(*) AS total_messages
       FROM messages
@@ -333,6 +374,19 @@ export class SessionStore {
       ? Math.round((totalMessages / totalSessions) * 100) / 100
       : 0;
 
+    const topicCounts = new Map<string, number>();
+    const rowsForTopics = this.getAllMessagesWithMetadata().filter((row) => row.createdAt >= since);
+    for (const row of rowsForTopics) {
+      const topics = row.metadata?.topics ?? row.metadata?.keywords ?? [];
+      for (const topic of topics) {
+        topicCounts.set(topic, (topicCounts.get(topic) ?? 0) + 1);
+      }
+    }
+    const topTopics = Array.from(topicCounts.entries())
+      .sort((a, b) => b[1] - a[1] || a[0].localeCompare(b[0]))
+      .slice(0, topLimit)
+      .map(([topic, occurrences]) => ({ topic, occurrences }));
+
     return {
       daily: dailyRows.map((row) => ({
         day: row.day,
@@ -344,6 +398,11 @@ export class SessionStore {
         messages: row.messages,
         lastActivity: row.last_activity,
       })),
+      topTools: topToolsRows.map((row) => ({
+        toolName: row.tool_name,
+        executions: row.executions,
+      })),
+      topTopics,
       averageMessagesPerSession,
       totalSessions,
       totalMessages,