diff --git a/src/main/services/CaptureService.ts b/src/main/services/CaptureService.ts
new file mode 100644
index 0000000..dc78465
--- /dev/null
+++ b/src/main/services/CaptureService.ts
@@ -0,0 +1,51 @@
+import type { NoteRepository } from '../repository/NoteRepository.js';
+import type { MediaStore } from './MediaStore.js';
+
+export interface CaptureDeps {
+  enqueue: (noteId: string) => Promise<void>;
+  celebrate: (noteId: string) => void;
+}
+
+export interface SubmitInput {
+  text: string;
+  images: ArrayBuffer[];
+}
+
+export class CaptureService {
+  constructor(
+    private repo: NoteRepository,
+    private store: MediaStore,
+    private deps: CaptureDeps
+  ) {}
+
+  async submit(input: SubmitInput): Promise<{ noteId: string }> {
+    const trimmed = input.text.trim();
+    if (trimmed.length === 0 && input.images.length === 0) {
+      throw new Error('empty submission');
+    }
+    const { id } = this.repo.create({ rawText: input.text });
+    if (input.images.length > 0) {
+      const rows = [];
+      for (const img of input.images) {
+        const buf = Buffer.from(img);
+        const saved = await this.store.saveImage(id, buf, 'image/png');
+        rows.push({
+          noteId: id,
+          kind: 'image' as const,
+          relPath: saved.relPath,
+          mime: saved.mime,
+          bytes: saved.bytes
+        });
+      }
+      this.repo.insertMedia(rows);
+    }
+    await this.deps.enqueue(id);
+    this.deps.celebrate(id);
+    return { noteId: id };
+  }
+
+  async deleteNote(noteId: string): Promise<void> {
+    this.repo.delete(noteId);
+    await this.store.deleteNoteDirectory(noteId);
+  }
+}
diff --git a/tests/unit/CaptureService.test.ts b/tests/unit/CaptureService.test.ts
new file mode 100644
index 0000000..52fd902
--- /dev/null
+++ b/tests/unit/CaptureService.test.ts
@@ -0,0 +1,60 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { mkdtempSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import Database from 'better-sqlite3';
+import { runMigrations } from '@main/db/migrations/index.js';
+import { NoteRepository } from '@main/repository/NoteRepository.js';
+import { MediaStore } from '@main/services/MediaStore.js';
+import { CaptureService } from '@main/services/CaptureService.js';
+
+describe('CaptureService', () => {
+  let db: Database.Database;
+  let repo: NoteRepository;
+  let store: MediaStore;
+  let tmp: string;
+  let enqueued: string[];
+  let celebrated: string[];
+  let svc: CaptureService;
+
+  beforeEach(() => {
+    db = new Database(':memory:');
+    runMigrations(db);
+    repo = new NoteRepository(db);
+    tmp = mkdtempSync(join(tmpdir(), 'inkling-capture-'));
+    store = new MediaStore(tmp);
+    enqueued = [];
+    celebrated = [];
+    svc = new CaptureService(repo, store, {
+      enqueue: async (id) => { enqueued.push(id); },
+      celebrate: (id) => { celebrated.push(id); }
+    });
+  });
+
+  it('persists text-only and triggers enqueue + celebrate', async () => {
+    const { noteId } = await svc.submit({ text: '안녕', images: [] });
+    expect(repo.findById(noteId)?.rawText).toBe('안녕');
+    expect(enqueued).toEqual([noteId]);
+    expect(celebrated).toEqual([noteId]);
+  });
+
+  it('saves images under media/{noteId}/', async () => {
+    const img = new Uint8Array([137, 80, 78, 71, 13, 10, 26, 10]).buffer;
+    const { noteId } = await svc.submit({ text: 'x', images: [img] });
+    const note = repo.findById(noteId)!;
+    expect(note.media).toHaveLength(1);
+    expect(note.media[0]!.relPath.startsWith(`media/${noteId}/`)).toBe(true);
+  });
+
+  it('rejects empty submit', async () => {
+    await expect(svc.submit({ text: '   ', images: [] })).rejects.toThrow(/empty/i);
+    expect(celebrated).toHaveLength(0);
+  });
+
+  it('deleteNote removes db row + media dir', async () => {
+    const img = new Uint8Array([0, 1, 2, 3]).buffer;
+    const { noteId } = await svc.submit({ text: 't', images: [img] });
+    await svc.deleteNote(noteId);
+    expect(repo.findById(noteId)).toBeNull();
+  });
+});