diff --git a/src/cli/ingest.ts b/src/cli/ingest.ts
index fe2fb98..1d85f0b 100644
--- a/src/cli/ingest.ts
+++ b/src/cli/ingest.ts
@@ -4,9 +4,9 @@
 import { readFileSync, writeFileSync, mkdirSync, existsSync, readdirSync, renameSync } from 'node:fs';
 import { join } from 'node:path';
 import matter from 'gray-matter';
-import chokidar from 'chokidar';
 import { callLLM, loadLLMConfig, type ChatRequest, type LLMConfigFromVault } from '../llm.js';
 import { preCheckConflict } from '../ingest.js';
+import { startInboxWatcher, type ActiveWatcher } from '../watcher.js';
 
 interface IngestOptions {
   mock?: boolean;
@@ -98,8 +98,7 @@ export async function ingestCommand(vaultPath: string, args: string[]): Promise<
 
 /**
  * Lauscht auf neue Dateien in 00_Inbox/ und ingestiert sie automatisch.
- * Nutzt chokidar (robuster als node:fs.watch auf Windows).
- * Debounce 1s, um mehrfache Events pro Datei zu vermeiden.
+ * Wrapper um startInboxWatcher mit Ctrl+C-Handling.
  */
 async function watchInbox(
   vaultPath: string,
@@ -110,40 +109,23 @@ async function watchInbox(
   dryRun: boolean,
   inboxDir: string,
 ): Promise<void> {
-  const watcher = chokidar.watch(inboxDir, {
-    ignored: /(^|[/\\])(\..*|Verarbeitet|Problemfaelle|.*\.tmp$)/,
-    persistent: true,
-    ignoreInitial: true,
-    awaitWriteFinish: { stabilityThreshold: 500, pollInterval: 100 },
-  });
-
-  let debounceTimer: NodeJS.Timeout | null = null;
-  const pending = new Set<string>();
-
-  watcher.on('add', (filePath) => {
-    if (!filePath.endsWith('.md')) return;
-    pending.add(filePath);
-    if (debounceTimer) clearTimeout(debounceTimer);
-    debounceTimer = setTimeout(async () => {
-      const toProcess = [...pending];
-      pending.clear();
-      for (const notePath of toProcess) {
-        console.log(`[watch] Neue Notiz: ${notePath}`);
-        try {
-          await processNote(vaultPath, notePath, schema, sysIndex, wikiIndex, llmConfig, dryRun);
-        } catch (err) {
-          console.error(`[watch] FEHLER: ${(err as Error).message}`);
-          moveToProblemfaelle(vaultPath, notePath, (err as Error).message);
-        }
-      }
-    }, 1000);
+  let activeWatcher: ActiveWatcher | null = null;
+  activeWatcher = await startInboxWatcher(inboxDir, {
+    processNote: async (notePath: string) => {
+      console.log(`[watch] Neue Notiz: ${notePath}`);
+      await processNote(vaultPath, notePath, schema, sysIndex, wikiIndex, llmConfig, dryRun);
+    },
+    onError: (err: Error, notePath: string) => {
+      console.error(`[watch] FEHLER: ${err.message}`);
+      moveToProblemfaelle(vaultPath, notePath, err.message);
+    },
   });
 
   // Auf Ctrl+C warten
   await new Promise<void>((resolve) => {
     process.on('SIGINT', () => {
       console.log('\n=== Watch-Mode beendet. ===');
-      watcher.close().then(() => resolve());
+      activeWatcher?.close().then(() => resolve());
     });
   });
 }
diff --git a/src/watcher.ts b/src/watcher.ts
new file mode 100644
index 0000000..f37b4e2
--- /dev/null
+++ b/src/watcher.ts
@@ -0,0 +1,60 @@
+// Watcher-Logik (testbar)
+// Bonus 21: Watcher in separate Datei, mit Dependency-Injection
+// fuer processNote (testbar ohne chokidar)
+
+import chokidar from 'chokidar';
+
+export interface WatcherDeps {
+  processNote: (notePath: string) => Promise<void>;
+  onError?: (err: Error, notePath: string) => void;
+  debounceMs?: number;
+}
+
+export interface ActiveWatcher {
+  close: () => Promise<void>;
+}
+
+/**
+ * Startet einen Watcher auf `inboxDir` und ruft `processNote` fuer jede
+ * neue .md-Datei (mit Debounce).
+ *
+ * Testbar: processNote wird als Dependency uebergeben.
+ */
+export async function startInboxWatcher(inboxDir: string, deps: WatcherDeps): Promise<ActiveWatcher> {
+  const debounceMs = deps.debounceMs ?? 1000;
+  const onError = deps.onError ?? ((err) => console.error(`[watch] FEHLER: ${err.message}`));
+
+  const watcher = chokidar.watch(inboxDir, {
+    ignored: /(^|[/\\])(\..*|Verarbeitet|Problemfaelle|.*\.tmp$)/,
+    persistent: true,
+    ignoreInitial: true,
+    awaitWriteFinish: { stabilityThreshold: 500, pollInterval: 100 },
+  });
+
+  let debounceTimer: ReturnType<typeof setTimeout> | null = null;
+  const pending = new Set<string>();
+
+  watcher.on('add', (filePath) => {
+    if (!filePath.endsWith('.md')) return;
+    pending.add(filePath);
+    if (debounceTimer) clearTimeout(debounceTimer);
+    debounceTimer = setTimeout(async () => {
+      const toProcess = [...pending];
+      pending.clear();
+      for (const notePath of toProcess) {
+        try {
+          await deps.processNote(notePath);
+        } catch (err) {
+          onError(err as Error, notePath);
+        }
+      }
+    }, debounceMs);
+  });
+
+  return {
+    close: async () => {
+      if (debounceTimer) clearTimeout(debounceTimer);
+      await watcher.close();
+    },
+  };
+}
diff --git a/tests/watcher.test.ts b/tests/watcher.test.ts
new file mode 100644
index 0000000..5f175c1
--- /dev/null
+++ b/tests/watcher.test.ts
@@ -0,0 +1,155 @@
+// Tests fuer startInboxWatcher
+// Bonus 21: Watcher-Edge-Cases
+
+import { describe, it, expect, afterEach } from 'vitest';
+import { mkdtempSync, mkdirSync, writeFileSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { startInboxWatcher, type ActiveWatcher } from '../src/watcher.js';
+
+const watchers: ActiveWatcher[] = [];
+afterEach(async () => {
+  for (const w of watchers) await w.close();
+  watchers.length = 0;
+});
+
+function setupInbox(): string {
+  const dir = mkdtempSync(join(tmpdir(), 'mindomat-watcher-test-'));
+  // Inbox-Struktur
+  for (const d of ['00_Inbox', '00_Inbox/Verarbeitet', '00_Inbox/Problemfaelle']) {
+    mkdirSync(join(dir, d), { recursive: true });
+  }
+  return dir;
+}
+
+describe('startInboxWatcher', () => {
+  it('startet und schliesst sauber', async () => {
+    const inbox = setupInbox();
+    const processed: string[] = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async (p) => { processed.push(p); },
+      debounceMs: 50,
+    });
+    watchers.push(watcher);
+    expect(watcher).toBeDefined();
+    expect(typeof watcher.close).toBe('function');
+    await watcher.close();
+  });
+
+  it('verarbeitet neue .md-Dateien', async () => {
+    const inbox = setupInbox();
+    const processed: string[] = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async (p) => { processed.push(p); },
+      debounceMs: 100,
+    });
+    watchers.push(watcher);
+
+    // Warte, bis Watcher bereit ist
+    await new Promise((r) => setTimeout(r, 500));
+
+    // Schreibe neue .md-Datei
+    const notePath = join(inbox, '00_Inbox', 'test.md');
+    writeFileSync(notePath, '# Test');
+
+    // Warte auf Debounce + Verarbeitung
+    await new Promise((r) => setTimeout(r, 1500));
+
+    expect(processed.length).toBe(1);
+    expect(processed[0]).toContain('test.md');
+  });
+
+  it('ignoriert Nicht-.md-Dateien', async () => {
+    const inbox = setupInbox();
+    const processed: string[] = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async (p) => { processed.push(p); },
+      debounceMs: 100,
+    });
+    watchers.push(watcher);
+
+    await new Promise((r) => setTimeout(r, 500));
+
+    // Schreibe .txt-Datei (sollte ignoriert werden)
+    writeFileSync(join(inbox, '00_Inbox', 'test.txt'), 'not markdown');
+    await new Promise((r) => setTimeout(r, 800));
+
+    expect(processed.length).toBe(0);
+  });
+
+  it('ignoriert Verarbeitet/-Unterordner', async () => {
+    const inbox = setupInbox();
+    const processed: string[] = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async (p) => { processed.push(p); },
+      debounceMs: 100,
+    });
+    watchers.push(watcher);
+
+    await new Promise((r) => setTimeout(r, 500));
+
+    // In Verarbeitet/ schreiben (sollte ignoriert werden)
+    writeFileSync(join(inbox, '00_Inbox', 'Verarbeitet', 'old.md'), '# alt');
+    await new Promise((r) => setTimeout(r, 800));
+
+    expect(processed.length).toBe(0);
+  });
+
+  it('Debounce: mehrere schnelle Writes -> eine Verarbeitung', async () => {
+    const inbox = setupInbox();
+    const processed: string[] = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async (p) => { processed.push(p); },
+      debounceMs: 500,
+    });
+    watchers.push(watcher);
+
+    await new Promise((r) => setTimeout(r, 500));
+
+    // 3 schnelle Writes
+    for (let i = 0; i < 3; i++) {
+      writeFileSync(join(inbox, '00_Inbox', `note-${i}.md`), `# Note ${i}`);
+      await new Promise((r) => setTimeout(r, 50));
+    }
+    // Warte auf Debounce
+    await new Promise((r) => setTimeout(r, 1500));
+
+    // Alle 3 Notizen sollten verarbeitet sein
+    expect(processed.length).toBeGreaterThanOrEqual(1);
+    expect(processed.length).toBeLessThanOrEqual(3);
+  });
+
+  it('Fehler in processNote werden via onError-Callback gemeldet', async () => {
+    const inbox = setupInbox();
+    const errors: Array<{ err: Error; path: string }> = [];
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async () => { throw new Error('Test-Fehler'); },
+      onError: (err, path) => { errors.push({ err, path }); },
+      debounceMs: 100,
+    });
+    watchers.push(watcher);
+
+    await new Promise((r) => setTimeout(r, 500));
+
+    writeFileSync(join(inbox, '00_Inbox', 'fail.md'), '# fail');
+    await new Promise((r) => setTimeout(r, 1500));
+
+    expect(errors.length).toBeGreaterThanOrEqual(1);
+    expect(errors[0].err.message).toBe('Test-Fehler');
+    expect(errors[0].path).toContain('fail.md');
+  });
+
+  it('schliesst sauber ohne haengende Prozesse', async () => {
+    const inbox = setupInbox();
+    const watcher = await startInboxWatcher(inbox, {
+      processNote: async () => {},
+      debounceMs: 50,
+    });
+
+    // Vor close: Watcher aktiv
+    expect(watcher).toBeDefined();
+
+    // Close sollte schnell gehen und keine Errors werfen
+    await expect(watcher.close()).resolves.not.toThrow();
+  });
+});