diff --git a/.gitignore b/.gitignore
index 96ffabb..c29b40b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ coverage/
 *.log
 .env*
 !.env.example
+!.env.test.example
 backend/target/
 frontend/node_modules/
 frontend/dist/
diff --git a/e2e/.env.test.example b/e2e/.env.test.example
new file mode 100644
index 0000000..d231ada
--- /dev/null
+++ b/e2e/.env.test.example
@@ -0,0 +1,3 @@
+# Copy this file to .env.test and fill in your real API key.
+# This file is gitignored and MUST NOT be committed.
+OPENAI_TEST_API_KEY=sk-your-key-here
diff --git a/e2e/.gitignore b/e2e/.gitignore
index 90d2772..7d28663 100644
--- a/e2e/.gitignore
+++ b/e2e/.gitignore
@@ -3,3 +3,4 @@ dist/
 test-results/
 playwright-report/
 blob-report/
+.env.test
diff --git a/e2e/package-lock.json b/e2e/package-lock.json
index d830792..d7afc49 100644
--- a/e2e/package-lock.json
+++ b/e2e/package-lock.json
@@ -8,6 +8,7 @@
       "devDependencies": {
         "@playwright/test": "^1.50.0",
         "@types/pg": "^8.11.0",
+        "dotenv": "^17.3.1",
         "pg": "^8.13.0",
         "tsx": "^4.21.0"
       }
@@ -492,6 +493,19 @@
         "pg-types": "^2.2.0"
       }
     },
+    "node_modules/dotenv": {
+      "version": "17.3.1",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-17.3.1.tgz",
+      "integrity": "sha512-IO8C/dzEb6O3F9/twg6ZLXz164a2fhTnEWb95H23Dm4OuN+92NmEAlTrupP9VW6Jm3sO26tQlqyvyi4CsnY9GA==",
+      "dev": true,
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://dotenvx.com"
+      }
+    },
     "node_modules/esbuild": {
       "version": "0.27.4",
       "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.27.4.tgz",
diff --git a/e2e/package.json b/e2e/package.json
index bc537d0..bd1ea82 100644
--- a/e2e/package.json
+++ b/e2e/package.json
@@ -9,8 +9,9 @@
   },
   "devDependencies": {
     "@playwright/test": "^1.50.0",
+    "@types/pg": "^8.11.0",
+    "dotenv": "^17.3.1",
     "pg": "^8.13.0",
-    "tsx": "^4.21.0",
-    "@types/pg": "^8.11.0"
+    "tsx": "^4.21.0"
   }
 }
diff --git a/e2e/tests/generation-live.spec.ts b/e2e/tests/generation-live.spec.ts
new file mode 100644
index 0000000..ba14102
--- /dev/null
+++ b/e2e/tests/generation-live.spec.ts
@@ -0,0 +1,192 @@
+/**
+ * E2E UAT: Synthesis generation with a real OpenAI API key.
+ *
+ * Exercises the full pipeline: settings, API key encryption, model resolution,
+ * LLM call (search + rewrite), response parsing, and synthesis storage.
+ *
+ * Gated by OPENAI_TEST_API_KEY in e2e/.env.test — skips if not set.
+ * Uses gpt-4o-mini to keep cost under $0.01 per run.
+ */
+
+import { test, expect } from '@playwright/test';
+import * as dotenv from 'dotenv';
+import * as path from 'path';
+import { loginAsUser } from '../helpers/auth';
+
+// Load .env.test from the e2e directory
+dotenv.config({ path: path.resolve(__dirname, '..', '.env.test') });
+
+const OPENAI_KEY = process.env.OPENAI_TEST_API_KEY;
+
+/** Helper to make an authenticated API call from the browser context. */
+async function apiCall(
+  page: any,
+  method: string,
+  url: string,
+  body?: object,
+): Promise<{ status: number; data: any }> {
+  return page.evaluate(
+    async ({
+      method,
+      url,
+      body,
+    }: {
+      method: string;
+      url: string;
+      body?: object;
+    }) => {
+      const options: RequestInit = {
+        method,
+        headers: {
+          'Content-Type': 'application/json',
+          'X-Requested-With': 'XMLHttpRequest',
+        },
+        credentials: 'same-origin',
+      };
+      if (body) {
+        options.body = JSON.stringify(body);
+      }
+      const resp = await fetch(url, options);
+      const data = await resp.json().catch(() => null);
+      return { status: resp.status, data };
+    },
+    { method, url, body },
+  );
+}
+
+/** Wait for SSE generation to complete, return the synthesis_id. */
+async function waitForGenerationComplete(
+  page: any,
+  jobId: string,
+  timeoutMs = 120_000,
+): Promise<string> {
+  return page.evaluate(
+    async ({ jobId, timeoutMs }: { jobId: string; timeoutMs: number }) => {
+      return new Promise<string>((resolve, reject) => {
+        const timer = setTimeout(
+          () => reject(new Error('Generation timed out')),
+          timeoutMs,
+        );
+        const es = new EventSource(
+          `/api/v1/syntheses/generate/${jobId}/progress`,
+        );
+        es.addEventListener('complete', (event: MessageEvent) => {
+          clearTimeout(timer);
+          es.close();
+          const parsed = JSON.parse(event.data);
+          resolve(parsed.synthesis_id);
+        });
+        es.addEventListener('error', (event: MessageEvent) => {
+          clearTimeout(timer);
+          es.close();
+          try {
+            const parsed = JSON.parse(event.data);
+            reject(new Error(`Generation failed: ${parsed.message}`));
+          } catch {
+            reject(new Error('Generation failed with unknown error'));
+          }
+        });
+        es.onerror = () => {
+          clearTimeout(timer);
+          es.close();
+          reject(new Error('SSE connection error'));
+        };
+      });
+    },
+    { jobId, timeoutMs },
+  );
+}
+
+test.describe('Live generation with OpenAI', () => {
+  test.skip(!OPENAI_KEY, 'OPENAI_TEST_API_KEY not set in e2e/.env.test');
+
+  test('full generation pipeline produces valid synthesis', async ({
+    page,
+  }) => {
+    test.setTimeout(180_000);
+
+    // Navigate to app first (required for cookie domain), then login
+    // OpenAI provider is already enabled from the migration seed data
+    await page.goto('/');
+    await loginAsUser(page);
+
+    // Step 2: Configure settings
+    const settingsResp = await apiCall(page, 'PUT', '/api/v1/settings', {
+      theme: 'AI Weekly',
+      max_age_days: 7,
+      categories: ['AI News'],
+      max_items_per_category: 5,
+      search_agent_behavior: '',
+      ai_provider: 'openai',
+      ai_model: 'gpt-4o-mini',
+      ai_model_writing: 'gpt-4o-mini',
+    });
+    expect(settingsResp.status).toBe(200);
+
+    // Step 3: Store the real OpenAI API key
+    const keyResp = await apiCall(page, 'POST', '/api/v1/user/api-keys', {
+      provider_name: 'openai',
+      api_key: OPENAI_KEY,
+    });
+    expect(keyResp.status).toBe(200);
+
+    // Step 4: Add a source
+    const sourceResp = await apiCall(page, 'POST', '/api/v1/sources', {
+      title: 'OpenAI Blog',
+      url: 'https://openai.com/blog',
+    });
+    expect(sourceResp.status).toBe(200);
+
+    // Step 5: Trigger generation
+    const genResp = await apiCall(
+      page,
+      'POST',
+      '/api/v1/syntheses/generate',
+    );
+    expect(genResp.status).toBe(202);
+    const jobId = genResp.data.job_id;
+    expect(jobId).toBeTruthy();
+
+    // Step 6: Wait for SSE completion
+    const synthesisId = await waitForGenerationComplete(page, jobId);
+    expect(synthesisId).toBeTruthy();
+
+    // Step 7: Fetch the full synthesis
+    const synthResp = await apiCall(
+      page,
+      'GET',
+      `/api/v1/syntheses/${synthesisId}`,
+    );
+    expect(synthResp.status).toBe(200);
+    const synthesis = synthResp.data;
+
+    // Step 8: Validate structure
+    expect(synthesis.status).toBe('completed');
+    expect(synthesis.sections).toBeDefined();
+    expect(synthesis.sections.length).toBeGreaterThanOrEqual(1);
+
+    for (const section of synthesis.sections) {
+      // Section has a title (category name)
+      expect(section.title).toBeTruthy();
+      expect(typeof section.title).toBe('string');
+
+      // Section has items
+      expect(section.items).toBeDefined();
+      expect(section.items.length).toBeGreaterThanOrEqual(1);
+
+      for (const item of section.items) {
+        // Each item has a non-empty title
+        expect(item.title).toBeTruthy();
+        expect(typeof item.title).toBe('string');
+
+        // Each item URL starts with http
+        expect(item.url).toBeTruthy();
+        expect(item.url.startsWith('http')).toBe(true);
+
+        // Each item summary is non-trivial (> 50 chars)
+        expect(item.summary).toBeTruthy();
+        expect(item.summary.length).toBeGreaterThan(50);
+      }
+    }
+  });
+});