diff --git a/apps/server/db/repositories/drizzle/log-chunk.test.ts b/apps/server/db/repositories/drizzle/log-chunk.test.ts
new file mode 100644
index 0000000..0c48d6a
--- /dev/null
+++ b/apps/server/db/repositories/drizzle/log-chunk.test.ts
@@ -0,0 +1,129 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { DrizzleLogChunkRepository } from './log-chunk.js';
+import { createTestDatabase } from './test-helpers.js';
+import type { DrizzleDatabase } from '../../index.js';
+
+describe('DrizzleLogChunkRepository', () => {
+  let db: DrizzleDatabase;
+  let repo: DrizzleLogChunkRepository;
+  const testAgentId = 'agent-test-001';
+
+  beforeEach(() => {
+    db = createTestDatabase();
+    repo = new DrizzleLogChunkRepository(db);
+  });
+
+  it('AskUserQuestion chunk — questionsCount upserted correctly', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'tool_use', name: 'AskUserQuestion', input: { questions: [{}, {}] } }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([{
+      agentId: testAgentId,
+      questionsCount: 2,
+      subagentsCount: 0,
+      compactionsCount: 0,
+    }]);
+  });
+
+  it('Agent tool chunk — subagentsCount incremented', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'tool_use', name: 'Agent' }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([{
+      agentId: testAgentId,
+      questionsCount: 0,
+      subagentsCount: 1,
+      compactionsCount: 0,
+    }]);
+  });
+
+  it('Compaction event — compactionsCount incremented', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'system', subtype: 'init', source: 'compact' }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([{
+      agentId: testAgentId,
+      questionsCount: 0,
+      subagentsCount: 0,
+      compactionsCount: 1,
+    }]);
+  });
+
+  it('Irrelevant chunk type — no metrics row created', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'text', text: 'hello' }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([]);
+  });
+
+  it('Malformed JSON chunk — chunk persisted, metrics row absent', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: 'not-valid-json',
+    });
+    const chunks = await repo.findByAgentId(testAgentId);
+    expect(chunks).toHaveLength(1);
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([]);
+  });
+
+  it('Multiple inserts, same agent — counts accumulate additively', async () => {
+    // 3 Agent tool chunks
+    for (let i = 0; i < 3; i++) {
+      await repo.insertChunk({
+        agentId: testAgentId,
+        agentName: 'test-agent',
+        sessionNumber: 1,
+        content: JSON.stringify({ type: 'tool_use', name: 'Agent' }),
+      });
+    }
+    // 1 AskUserQuestion with 2 questions
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'tool_use', name: 'AskUserQuestion', input: { questions: [{}, {}] } }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([{
+      agentId: testAgentId,
+      questionsCount: 2,
+      subagentsCount: 3,
+      compactionsCount: 0,
+    }]);
+  });
+
+  it('findMetricsByAgentIds with empty array — returns []', async () => {
+    const metrics = await repo.findMetricsByAgentIds([]);
+    expect(metrics).toEqual([]);
+  });
+
+  it('findMetricsByAgentIds with agentId that has no metrics row — returns []', async () => {
+    await repo.insertChunk({
+      agentId: testAgentId,
+      agentName: 'test-agent',
+      sessionNumber: 1,
+      content: JSON.stringify({ type: 'text', text: 'hello' }),
+    });
+    const metrics = await repo.findMetricsByAgentIds([testAgentId]);
+    expect(metrics).toEqual([]);
+  });
+});
diff --git a/apps/server/db/repositories/drizzle/log-chunk.ts b/apps/server/db/repositories/drizzle/log-chunk.ts
index 9d4632b..5d30c0b 100644
--- a/apps/server/db/repositories/drizzle/log-chunk.ts
+++ b/apps/server/db/repositories/drizzle/log-chunk.ts
@@ -4,10 +4,10 @@
  * Implements LogChunkRepository interface using Drizzle ORM.
  */
 
-import { eq, asc, max, inArray } from 'drizzle-orm';
+import { eq, asc, max, inArray, sql } from 'drizzle-orm';
 import { nanoid } from 'nanoid';
 import type { DrizzleDatabase } from '../../index.js';
-import { agentLogChunks } from '../../schema.js';
+import { agentLogChunks, agentMetrics } from '../../schema.js';
 import type { LogChunkRepository } from '../log-chunk-repository.js';
 
 export class DrizzleLogChunkRepository implements LogChunkRepository {
@@ -19,13 +19,58 @@ export class DrizzleLogChunkRepository implements LogChunkRepository {
     sessionNumber: number;
     content: string;
   }): Promise<void> {
-    await this.db.insert(agentLogChunks).values({
-      id: nanoid(),
-      agentId: data.agentId,
-      agentName: data.agentName,
-      sessionNumber: data.sessionNumber,
-      content: data.content,
-      createdAt: new Date(),
+    // better-sqlite3 is synchronous — transaction callback must be sync, use .run() not await
+    this.db.transaction((tx) => {
+      // 1. Always insert the chunk row first
+      tx.insert(agentLogChunks).values({
+        id: nanoid(),
+        agentId: data.agentId,
+        agentName: data.agentName,
+        sessionNumber: data.sessionNumber,
+        content: data.content,
+        createdAt: new Date(),
+      }).run();
+
+      // 2. Parse content and determine metric increments
+      //    Wrap only the parse + upsert block — chunk insert is not rolled back on parse failure
+      try {
+        const parsed = JSON.parse(data.content);
+        let deltaQuestions = 0;
+        let deltaSubagents = 0;
+        let deltaCompactions = 0;
+
+        if (parsed.type === 'tool_use' && parsed.name === 'AskUserQuestion') {
+          deltaQuestions = parsed.input?.questions?.length ?? 0;
+        } else if (parsed.type === 'tool_use' && parsed.name === 'Agent') {
+          deltaSubagents = 1;
+        } else if (parsed.type === 'system' && parsed.subtype === 'init' && parsed.source === 'compact') {
+          deltaCompactions = 1;
+        }
+
+        // 3. Only upsert if there is something to increment
+        if (deltaQuestions > 0 || deltaSubagents > 0 || deltaCompactions > 0) {
+          tx.insert(agentMetrics)
+            .values({
+              agentId: data.agentId,
+              questionsCount: deltaQuestions,
+              subagentsCount: deltaSubagents,
+              compactionsCount: deltaCompactions,
+              updatedAt: new Date(),
+            })
+            .onConflictDoUpdate({
+              target: agentMetrics.agentId,
+              set: {
+                questionsCount: sql`${agentMetrics.questionsCount} + ${deltaQuestions}`,
+                subagentsCount: sql`${agentMetrics.subagentsCount} + ${deltaSubagents}`,
+                compactionsCount: sql`${agentMetrics.compactionsCount} + ${deltaCompactions}`,
+                updatedAt: new Date(),
+              },
+            })
+            .run();
+        }
+      } catch {
+        // Malformed JSON — skip metric upsert, chunk insert already committed within transaction
+      }
     });
   }
 
@@ -69,4 +114,22 @@ export class DrizzleLogChunkRepository implements LogChunkRepository {
 
     return result[0]?.maxSession ?? 0;
   }
+
+  async findMetricsByAgentIds(agentIds: string[]): Promise<{
+    agentId: string;
+    questionsCount: number;
+    subagentsCount: number;
+    compactionsCount: number;
+  }[]> {
+    if (agentIds.length === 0) return [];
+    return this.db
+      .select({
+        agentId: agentMetrics.agentId,
+        questionsCount: agentMetrics.questionsCount,
+        subagentsCount: agentMetrics.subagentsCount,
+        compactionsCount: agentMetrics.compactionsCount,
+      })
+      .from(agentMetrics)
+      .where(inArray(agentMetrics.agentId, agentIds));
+  }
 }
diff --git a/apps/server/db/repositories/log-chunk-repository.ts b/apps/server/db/repositories/log-chunk-repository.ts
index 0283a0b..1e1f8a2 100644
--- a/apps/server/db/repositories/log-chunk-repository.ts
+++ b/apps/server/db/repositories/log-chunk-repository.ts
@@ -27,4 +27,16 @@ export interface LogChunkRepository {
   deleteByAgentId(agentId: string): Promise<void>;
 
   getSessionCount(agentId: string): Promise<number>;
+
+  /**
+   * Batch-fetch pre-computed metrics for multiple agent IDs.
+   * Returns one row per agent that has metrics. Agents with no
+   * matching row in agent_metrics are omitted (not returned as zeros).
+   */
+  findMetricsByAgentIds(agentIds: string[]): Promise<{
+    agentId: string;
+    questionsCount: number;
+    subagentsCount: number;
+    compactionsCount: number;
+  }[]>;
 }