diff --git a/src/app.js b/src/app.js
new file mode 100644
index 0000000..ae0ba35
--- /dev/null
+++ b/src/app.js
@@ -0,0 +1,116 @@
+import path from 'node:path';
+import express from 'express';
+import multer from 'multer';
+import { rateLimit } from 'express-rate-limit';
+import { v4 as uuidv4 } from 'uuid';
+import { resolve as resolveConverter, listTargetFormats } from './converters/registry.js';
+import { registerImageConverters } from './converters/image.js';
+import { registerImageToPdfConverter } from './converters/imageToPdf.js';
+import { registerDocumentConverters } from './converters/document.js';
+import { resolveInputFormat } from './mime.js';
+import { deleteIfExists } from './storage.js';
+import { createJob, getJobById } from './jobs/jobRepository.js';
+
+let convertersRegistered = false;
+
+function registerAllConverters() {
+  if (convertersRegistered) return;
+  registerImageConverters();
+  registerImageToPdfConverter();
+  registerDocumentConverters();
+  convertersRegistered = true;
+}
+
+export function createApp(config, pool) {
+  registerAllConverters();
+
+  const app = express();
+
+  const storage = multer.diskStorage({
+    destination: (req, file, cb) => cb(null, path.join(config.storageDir, 'uploads')),
+    filename: (req, file, cb) => {
+      const ext = path.extname(file.originalname).slice(1).toLowerCase();
+      cb(null, `${uuidv4()}.${ext}`);
+    },
+  });
+
+  const upload = multer({
+    storage,
+    limits: {
+      fileSize: config.maxFileSizeMb * 1024 * 1024,
+      files: 10,
+    },
+  });
+
+  const jobsRateLimiter = rateLimit({
+    windowMs: config.rateLimitWindowMinutes * 60 * 1000,
+    limit: config.rateLimitMaxJobs,
+    standardHeaders: 'draft-8',
+    legacyHeaders: false,
+  });
+
+  app.get('/api/formats', (req, res) => {
+    const source = String(req.query.source ?? '').toLowerCase();
+    res.json({ targets: listTargetFormats(source) });
+  });
+
+  app.post('/api/jobs', jobsRateLimiter, upload.array('files', 10), async (req, res) => {
+    if (!req.files || req.files.length === 0) {
+      return res.status(400).json({ error: 'No files uploaded' });
+    }
+
+    let targetFormats;
+    try {
+      targetFormats = JSON.parse(req.body.targetFormats ?? '[]');
+    } catch {
+      return res.status(400).json({ error: 'targetFormats must be a JSON array' });
+    }
+
+    if (!Array.isArray(targetFormats) || targetFormats.length !== req.files.length) {
+      return res.status(400).json({ error: 'targetFormats must have one entry per uploaded file' });
+    }
+
+    const results = [];
+    for (let i = 0; i < req.files.length; i += 1) {
+      const file = req.files[i];
+      const targetFormat = targetFormats[i];
+      const id = path.basename(file.filename, path.extname(file.filename));
+      const sourceFormat = path.extname(file.filename).slice(1).toLowerCase();
+
+      const { mime, valid } = await resolveInputFormat(file.path, sourceFormat);
+      if (!valid) {
+        await deleteIfExists(file.path);
+        results.push({ file: file.originalname, error: 'File content does not match its extension' });
+        continue;
+      }
+
+      const registryEntry = resolveConverter(sourceFormat, targetFormat);
+      if (!registryEntry) {
+        await deleteIfExists(file.path);
+        results.push({
+          file: file.originalname,
+          error: `Unsupported conversion: ${sourceFormat} to ${targetFormat}`,
+        });
+        continue;
+      }
+
+      const expiresAt = new Date(Date.now() + config.retentionHours * 3600 * 1000);
+      await createJob(pool, {
+        id,
+        family: registryEntry.family,
+        sourceFormat,
+        targetFormat,
+        originalFilename: file.originalname,
+        inputPath: file.filename,
+        inputMimeType: mime,
+        expiresAt,
+      });
+
+      results.push({ file: file.originalname, id, status: 'pending' });
+    }
+
+    res.status(201).json({ jobs: results });
+  });
+
+  return app;
+}
diff --git a/test/api/jobs.test.js b/test/api/jobs.test.js
new file mode 100644
index 0000000..c4adad8
--- /dev/null
+++ b/test/api/jobs.test.js
@@ -0,0 +1,116 @@
+import { describe, it, expect, beforeAll, afterAll, beforeEach } from 'vitest';
+import request from 'supertest';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import os from 'node:os';
+import { createApp } from '../../src/app.js';
+import { getPool, closePool } from '../../src/db.js';
+import { loadConfig } from '../../src/config.js';
+import { getJobById } from '../../src/jobs/jobRepository.js';
+import { ensureStorageDirs } from '../../src/storage.js';
+
+let app;
+let pool;
+let config;
+
+beforeAll(async () => {
+  config = { ...loadConfig(), storageDir: await fs.mkdtemp(path.join(os.tmpdir(), 'converter-api-')) };
+  await ensureStorageDirs(config);
+  pool = getPool(config);
+  app = createApp(config, pool);
+});
+
+afterAll(async () => {
+  await closePool();
+  await fs.rm(config.storageDir, { recursive: true, force: true });
+});
+
+beforeEach(async () => {
+  await pool.query('DELETE FROM conversion_jobs');
+});
+
+describe('GET /api/formats', () => {
+  it('lists valid target formats for a known source format', async () => {
+    const response = await request(app).get('/api/formats').query({ source: 'png' });
+
+    expect(response.status).toBe(200);
+    expect(response.body.targets).toContain('webp');
+    expect(response.body.targets).toContain('pdf');
+  });
+
+  it('returns an empty list for an unknown source format', async () => {
+    const response = await request(app).get('/api/formats').query({ source: 'made-up' });
+
+    expect(response.status).toBe(200);
+    expect(response.body.targets).toEqual([]);
+  });
+});
+
+describe('POST /api/jobs', () => {
+  it('creates a pending job for a valid image upload', async () => {
+    const fixturePath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
+
+    const response = await request(app)
+      .post('/api/jobs')
+      .field('targetFormats', JSON.stringify(['webp']))
+      .attach('files', fixturePath, 'photo.png');
+
+    expect(response.status).toBe(201);
+    expect(response.body.jobs).toHaveLength(1);
+    expect(response.body.jobs[0].status).toBe('pending');
+    expect(response.body.jobs[0].file).toBe('photo.png');
+
+    const job = await getJobById(pool, response.body.jobs[0].id);
+    expect(job.status).toBe('pending');
+    expect(job.sourceFormat).toBe('png');
+    expect(job.targetFormat).toBe('webp');
+    expect(job.originalFilename).toBe('photo.png');
+    expect(job.inputMimeType).toBe('image/png');
+  });
+
+  it('rejects a file whose content does not match its extension, without failing the whole batch', async () => {
+    const fakePath = path.join(config.storageDir, 'fake.png');
+    await fs.writeFile(fakePath, 'not actually a png');
+
+    const response = await request(app)
+      .post('/api/jobs')
+      .field('targetFormats', JSON.stringify(['webp']))
+      .attach('files', fakePath, 'fake.png');
+
+    expect(response.status).toBe(201);
+    expect(response.body.jobs[0].error).toMatch(/does not match/);
+
+    await fs.unlink(fakePath);
+  });
+
+  it('rejects an unsupported source/target pair', async () => {
+    const fixturePath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
+
+    const response = await request(app)
+      .post('/api/jobs')
+      .field('targetFormats', JSON.stringify(['made-up-format']))
+      .attach('files', fixturePath, 'photo.png');
+
+    expect(response.status).toBe(201);
+    expect(response.body.jobs[0].error).toMatch(/Unsupported conversion/);
+  });
+
+  it('returns 400 when targetFormats length does not match the number of files', async () => {
+    const fixturePath = path.join(import.meta.dirname, '..', 'fixtures', 'sample.png');
+
+    const response = await request(app)
+      .post('/api/jobs')
+      .field('targetFormats', JSON.stringify([]))
+      .attach('files', fixturePath, 'photo.png');
+
+    expect(response.status).toBe(400);
+  });
+
+  it('returns 400 when no files are uploaded', async () => {
+    const response = await request(app)
+      .post('/api/jobs')
+      .field('targetFormats', JSON.stringify([]));
+
+    expect(response.status).toBe(400);
+  });
+});