diff --git a/api/scripts/sessions-indexer.ts b/api/scripts/sessions-indexer.ts
new file mode 100644
index 0000000..83cfc70
--- /dev/null
+++ b/api/scripts/sessions-indexer.ts
@@ -0,0 +1,50 @@
+#!/usr/bin/env tsx
+/**
+ * CLI do indexer de sessões Claude Code (Observabilidade/Espelho).
+ *
+ * Modos:
+ *   --full   Full scan de ~/.claude/projects -> SQLite em ~/.claude-work/sessions.db
+ *   --watch  Modo incremental (stub; implementação Task 8)
+ *
+ * Env:
+ *   OBSERVABILIDADE_DB  Override ao caminho da BD SQLite
+ */
+import { indexAll, DEFAULT_DB_PATH } from '../services/sessions/indexer.js'
+import { startWatcher } from '../services/sessions/watcher.js'
+
+async function main(): Promise<void> {
+  const args = process.argv.slice(2)
+  const mode = args.find((a) => a === '--full' || a === '--watch')
+  if (!mode) {
+    console.error('Uso: sessions-indexer.ts [--full|--watch]')
+    process.exit(1)
+  }
+
+  const dbPath = process.env.OBSERVABILIDADE_DB ?? DEFAULT_DB_PATH
+  console.log(`[indexer] modo=${mode} db=${dbPath}`)
+
+  if (mode === '--watch') {
+    startWatcher()
+    return
+  }
+
+  const start = Date.now()
+  let lastLogged = 0
+  const { indexed, failed } = await indexAll({
+    dbPath,
+    onProgress: (done, total) => {
+      if (done - lastLogged >= 50 || done === total) {
+        console.log(`[indexer] ${done}/${total}`)
+        lastLogged = done
+      }
+    },
+  })
+  const durationMs = Date.now() - start
+  const durationSec = (durationMs / 1000).toFixed(1)
+  console.log(`[indexer] concluído em ${durationSec}s · indexed=${indexed} failed=${failed}`)
+}
+
+main().catch((err) => {
+  console.error('[indexer] falha fatal:', err)
+  process.exit(2)
+})
diff --git a/api/services/sessions/indexer.ts b/api/services/sessions/indexer.ts
new file mode 100644
index 0000000..a2735bf
--- /dev/null
+++ b/api/services/sessions/indexer.ts
@@ -0,0 +1,98 @@
+import { readdirSync, statSync } from 'fs'
+import { homedir } from 'os'
+import { join } from 'path'
+import { parseSessionFile } from './parser.js'
+import { openSessionsDb, type SessionsDb } from './db.js'
+import type { SessionMeta } from '../../types/session.js'
+
+export const PROJECTS_ROOT = join(homedir(), '.claude', 'projects')
+export const DEFAULT_DB_PATH = join(homedir(), '.claude-work', 'sessions.db')
+
+/**
+ * Percorre a raiz de projectos Claude (profundidade 2) e devolve todos os .jsonl.
+ * Estrutura: ~/.claude/projects/<project-slug>/<session-uuid>.jsonl
+ */
+export function findAllJsonl(root: string = PROJECTS_ROOT): string[] {
+  const result: string[] = []
+  let entries: string[]
+  try {
+    entries = readdirSync(root)
+  } catch {
+    return result
+  }
+  for (const entry of entries) {
+    const projectDir = join(root, entry)
+    let st
+    try {
+      st = statSync(projectDir)
+    } catch {
+      continue
+    }
+    if (!st.isDirectory()) continue
+    let files: string[]
+    try {
+      files = readdirSync(projectDir)
+    } catch {
+      continue
+    }
+    for (const f of files) {
+      if (f.endsWith('.jsonl')) result.push(join(projectDir, f))
+    }
+  }
+  return result
+}
+
+/**
+ * Indexa um único ficheiro (parse + upsert). Uso individual — útil para o watcher (Task 8).
+ */
+export async function indexFile(db: SessionsDb, path: string): Promise<void> {
+  const { meta } = await parseSessionFile(path)
+  db.upsertSession(meta)
+}
+
+export interface IndexAllOptions {
+  dbPath?: string
+  onProgress?: (done: number, total: number) => void
+}
+
+/**
+ * Full scan: percorre todos os JSONL e faz upsert em lote (batch 50 via transacção).
+ */
+export async function indexAll(
+  options: IndexAllOptions = {},
+): Promise<{ indexed: number; failed: number }> {
+  const db = openSessionsDb(options.dbPath ?? DEFAULT_DB_PATH)
+  const files = findAllJsonl()
+  const BATCH = 50
+  let indexed = 0
+  let failed = 0
+  let batch: SessionMeta[] = []
+
+  try {
+    for (let i = 0; i < files.length; i++) {
+      try {
+        const { meta } = await parseSessionFile(files[i])
+        batch.push(meta)
+        if (batch.length >= BATCH) {
+          db.upsertMany(batch)
+          indexed += batch.length
+          batch = []
+        }
+      } catch (err) {
+        failed++
+        console.error(`[indexer] erro em ${files[i]}:`, err)
+      }
+      if (options.onProgress) {
+        options.onProgress(indexed + failed + batch.length, files.length)
+      }
+    }
+    if (batch.length > 0) {
+      db.upsertMany(batch)
+      indexed += batch.length
+    }
+  } finally {
+    db.close()
+  }
+
+  return { indexed, failed }
+}
diff --git a/api/services/sessions/watcher.ts b/api/services/sessions/watcher.ts
new file mode 100644
index 0000000..bdaf013
--- /dev/null
+++ b/api/services/sessions/watcher.ts
@@ -0,0 +1,7 @@
+/**
+ * Watcher incremental via chokidar — stub.
+ * Implementação completa na Task 8 (Pipeline: incremental watch + resiliência).
+ */
+export function startWatcher(): never {
+  throw new Error('watcher não implementado — ver Task 8')
+}