diff --git a/backend/tests/api_llm_logs_test.rs b/backend/tests/api_llm_logs_test.rs
new file mode 100644
index 0000000..a98dfae
--- /dev/null
+++ b/backend/tests/api_llm_logs_test.rs
@@ -0,0 +1,141 @@
+//! Integration tests for the LLM logs endpoint (GAP-2).
+//!
+//! Tests:
+//! - GET /api/v1/llm-logs/:job_id
+//!
+//! The handler first checks that a synthesis with the given job_id exists and
+//! belongs to the authenticated user, then returns the associated log entries.
+//! A random/unknown job_id therefore returns 404 (not an empty array).
+//!
+//! Requires a running Postgres instance. Set `TEST_DATABASE_URL` to run.
+
+mod common;
+
+use axum::http::StatusCode;
+
+fn require_test_db() -> bool {
+    std::env::var("TEST_DATABASE_URL").is_ok()
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Auth (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+#[tokio::test]
+async fn get_llm_logs_without_auth_returns_401() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let fake_job_id = uuid::Uuid::new_v4();
+
+    let (status, body) = app
+        .get_with_session(
+            &format!("/api/v1/llm-logs/{}", fake_job_id),
+            "invalid-session-token",
+        )
+        .await;
+
+    assert_eq!(
+        status,
+        StatusCode::UNAUTHORIZED,
+        "GET /llm-logs/:job_id without auth should return 401"
+    );
+    assert_eq!(body["error"], "unauthorized");
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Not found (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+/// The handler first verifies the job_id maps to a synthesis owned by the
+/// authenticated user. A random UUID that has no matching synthesis in the DB
+/// returns 404. This is intentional — it prevents enumeration of job IDs.
+#[tokio::test]
+async fn get_llm_logs_returns_404_for_unknown_job() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let (_user_id, session) = app
+        .create_authenticated_user("llm-logs-404@example.com")
+        .await;
+
+    let fake_job_id = uuid::Uuid::new_v4();
+    let (status, body) = app
+        .get_with_session(&format!("/api/v1/llm-logs/{}", fake_job_id), &session)
+        .await;
+
+    assert_eq!(
+        status,
+        StatusCode::NOT_FOUND,
+        "GET /llm-logs/:job_id for an unknown job_id should return 404"
+    );
+    assert_eq!(body["error"], "not_found");
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Happy path (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+/// Verify that when a synthesis exists for the given job_id, the endpoint
+/// returns 200 with a JSON array (the log entries, which may be empty if no
+/// LLM calls were recorded for the synthesis created directly via helper).
+#[tokio::test]
+async fn get_llm_logs_returns_array_for_known_job() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let (user_id, session) = app
+        .create_authenticated_user("llm-logs-array@example.com")
+        .await;
+
+    // Insert a test synthesis with a known job_id directly into the database.
+    // The `insert_test_synthesis` helper uses a random job_id internally; we
+    // need to insert our own to control the job_id used for the log lookup.
+    let job_id = uuid::Uuid::new_v4();
+    let sections = serde_json::json!([{
+        "title": "AI News",
+        "items": [{"title": "Article 1", "url": "https://example.com/1", "summary": "Summary"}]
+    }]);
+    let synthesis_id: (uuid::Uuid,) = sqlx::query_as(
+        "INSERT INTO syntheses (user_id, week, sections, status, job_id)
+         VALUES ($1, $2, $3, 'completed', $4)
+         RETURNING id",
+    )
+    .bind(user_id)
+    .bind("2026-W13")
+    .bind(&sections)
+    .bind(job_id)
+    .fetch_one(&app.pool)
+    .await
+    .expect("Failed to insert test synthesis");
+    let _ = synthesis_id; // verify it was inserted; we only need the job_id for the request
+
+    let (status, body) = app
+        .get_with_session(&format!("/api/v1/llm-logs/{}", job_id), &session)
+        .await;
+
+    assert_eq!(
+        status,
+        StatusCode::OK,
+        "GET /llm-logs/:job_id for a known synthesis should return 200"
+    );
+    assert!(
+        body.as_array().is_some(),
+        "Response should be a JSON array, got: {}", body
+    );
+    // No LLM calls were made for this synthesis (inserted directly), so the
+    // array is empty — but the important thing is it's a valid array.
+    assert!(
+        body.as_array().unwrap().is_empty(),
+        "Log array should be empty for a synthesis with no recorded LLM calls"
+    );
+}
diff --git a/backend/tests/api_stop_generation_test.rs b/backend/tests/api_stop_generation_test.rs
new file mode 100644
index 0000000..b1e88c0
--- /dev/null
+++ b/backend/tests/api_stop_generation_test.rs
@@ -0,0 +1,292 @@
+//! Integration tests for the stop generation endpoint (GAP-1).
+//!
+//! Tests:
+//! - POST /api/v1/syntheses/generate/:job_id/stop — stop a running job
+//!
+//! Covers authentication, ownership isolation, non-existent jobs,
+//! and stopping an active job.
+//!
+//! Requires a running Postgres instance. Set `TEST_DATABASE_URL` to run.
+
+mod common;
+
+use axum::http::StatusCode;
+
+fn require_test_db() -> bool {
+    std::env::var("TEST_DATABASE_URL").is_ok()
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Auth (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+#[tokio::test]
+async fn stop_without_auth_returns_401() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let fake_job_id = uuid::Uuid::new_v4();
+
+    let (status, body) = app
+        .post_with_session(
+            &format!("/api/v1/syntheses/generate/{}/stop", fake_job_id),
+            &serde_json::json!({}),
+            "invalid-session-token",
+        )
+        .await;
+
+    assert_eq!(
+        status,
+        StatusCode::UNAUTHORIZED,
+        "POST /syntheses/generate/:id/stop without auth should return 401"
+    );
+    assert_eq!(body["error"], "unauthorized");
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Not found (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+#[tokio::test]
+async fn stop_nonexistent_job_returns_404() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let (_user_id, session) = app
+        .create_authenticated_user("stop-404@example.com")
+        .await;
+
+    let fake_job_id = uuid::Uuid::new_v4();
+    let (status, body) = app
+        .post_with_session(
+            &format!("/api/v1/syntheses/generate/{}/stop", fake_job_id),
+            &serde_json::json!({}),
+            &session,
+        )
+        .await;
+
+    assert_eq!(
+        status,
+        StatusCode::NOT_FOUND,
+        "Stopping a non-existent job should return 404"
+    );
+    assert_eq!(body["error"], "not_found");
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Stop active job (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+/// Verify that stopping an active generation job returns 200.
+///
+/// The generation will fail at the LLM call (fake API key), but the job_id
+/// is registered in the job store immediately on trigger, so the stop
+/// endpoint should find it and return 200.
+#[tokio::test]
+async fn stop_active_job_returns_200() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+    let (_user_id, session) = app
+        .create_authenticated_user("stop-active@example.com")
+        .await;
+
+    // Configure provider settings
+    let settings = serde_json::json!({
+        "max_articles_per_source": 3,
+        "max_links_per_source": 8,
+        "use_brave_search": false,
+        "article_history_days": 90,
+        "batch_size": 5,
+        "source_extraction_window": 3,
+        "search_agent_behavior": "",
+        "ai_provider": "openai",
+        "ai_model": "",
+        "ai_model_websearch": "",
+        "rate_limit_max_requests": null,
+        "rate_limit_time_window_seconds": null
+    });
+    let (settings_status, _) = app
+        .put_with_session("/api/v1/settings", &settings, &session)
+        .await;
+    assert_eq!(settings_status, StatusCode::OK, "Settings save should succeed");
+
+    // Create a theme
+    let theme_body = serde_json::json!({
+        "name": "Stop Test Theme",
+        "theme": "Intelligence Artificielle",
+        "categories": ["AI News"],
+        "max_items_per_category": 4,
+        "max_age_days": 7,
+        "summary_length": 3
+    });
+    let (theme_status, theme_resp) = app
+        .post_with_session("/api/v1/themes", &theme_body, &session)
+        .await;
+    assert_eq!(theme_status.as_u16(), 201, "Theme creation should succeed");
+    let theme_id = theme_resp["id"].as_str().expect("Theme should have an id");
+
+    // Store a fake API key so the pipeline can start
+    let key_body = serde_json::json!({
+        "provider_name": "openai",
+        "api_key": "sk-fake-test-key-for-stop-test"
+    });
+    let (key_status, _) = app
+        .post_with_session("/api/v1/user/api-keys", &key_body, &session)
+        .await;
+    assert_eq!(key_status, StatusCode::OK, "API key store should succeed");
+
+    // Add a source so the pipeline has something to process
+    let source_body = serde_json::json!({
+        "title": "Stop Test Source",
+        "url": "https://example.com/blog",
+        "theme_id": theme_id
+    });
+    let (source_status, _) = app
+        .post_with_session("/api/v1/sources", &source_body, &session)
+        .await;
+    assert_eq!(source_status, StatusCode::CREATED, "Source creation should succeed");
+
+    // Trigger generation — returns 202 immediately, job runs async
+    let gen_body = serde_json::json!({ "theme_id": theme_id });
+    let (gen_status, gen_resp) = app
+        .post_with_session("/api/v1/syntheses/generate", &gen_body, &session)
+        .await;
+    assert_eq!(
+        gen_status,
+        StatusCode::ACCEPTED,
+        "Generation trigger should return 202"
+    );
+    let job_id = gen_resp["job_id"].as_str().expect("should have job_id");
+
+    // Immediately stop the job — it's registered in the job store at trigger time,
+    // so this should succeed even if generation hasn't finished yet.
+    let (stop_status, _) = app
+        .post_with_session(
+            &format!("/api/v1/syntheses/generate/{}/stop", job_id),
+            &serde_json::json!({}),
+            &session,
+        )
+        .await;
+
+    assert_eq!(
+        stop_status,
+        StatusCode::OK,
+        "Stopping an active job should return 200"
+    );
+}
+
+// ═══════════════════════════════════════════════════════════════════════════
+// Ownership isolation (1 test)
+// ═══════════════════════════════════════════════════════════════════════════
+
+/// Verify that User B cannot stop User A's generation job.
+///
+/// The stop endpoint uses `cancel_job(job_id, user_id)` which checks ownership,
+/// so it returns 404 if the job exists but belongs to a different user.
+#[tokio::test]
+async fn stop_other_users_job_returns_404() {
+    if !require_test_db() {
+        eprintln!("SKIPPED: TEST_DATABASE_URL not set");
+        return;
+    }
+
+    let app = common::TestApp::new().await;
+
+    // User A: create user + settings + theme + api key, then trigger generation
+    let (_user_a_id, session_a) = app
+        .create_authenticated_user("stop-owner-a@example.com")
+        .await;
+    let (_user_b_id, session_b) = app
+        .create_authenticated_user("stop-owner-b@example.com")
+        .await;
+
+    // Configure User A's settings
+    let settings = serde_json::json!({
+        "max_articles_per_source": 3,
+        "max_links_per_source": 8,
+        "use_brave_search": false,
+        "article_history_days": 90,
+        "batch_size": 5,
+        "source_extraction_window": 3,
+        "search_agent_behavior": "",
+        "ai_provider": "openai",
+        "ai_model": "",
+        "ai_model_websearch": "",
+        "rate_limit_max_requests": null,
+        "rate_limit_time_window_seconds": null
+    });
+    let (settings_status, _) = app
+        .put_with_session("/api/v1/settings", &settings, &session_a)
+        .await;
+    assert_eq!(settings_status, StatusCode::OK, "User A settings save should succeed");
+
+    // Create theme for User A
+    let theme_body = serde_json::json!({
+        "name": "Owner A Theme",
+        "theme": "Intelligence Artificielle",
+        "categories": ["AI News"],
+        "max_items_per_category": 4,
+        "max_age_days": 7,
+        "summary_length": 3
+    });
+    let (theme_status, theme_resp) = app
+        .post_with_session("/api/v1/themes", &theme_body, &session_a)
+        .await;
+    assert_eq!(theme_status.as_u16(), 201, "User A theme creation should succeed");
+    let theme_id_a = theme_resp["id"].as_str().expect("Theme should have an id");
+
+    // Store fake API key for User A
+    let key_body = serde_json::json!({
+        "provider_name": "openai",
+        "api_key": "sk-fake-test-key-for-ownership-test"
+    });
+    let (key_status, _) = app
+        .post_with_session("/api/v1/user/api-keys", &key_body, &session_a)
+        .await;
+    assert_eq!(key_status, StatusCode::OK, "User A API key store should succeed");
+
+    // Add source for User A
+    let source_body = serde_json::json!({
+        "title": "Owner A Source",
+        "url": "https://example-a.com/blog",
+        "theme_id": theme_id_a
+    });
+    let (source_status, _) = app
+        .post_with_session("/api/v1/sources", &source_body, &session_a)
+        .await;
+    assert_eq!(source_status, StatusCode::CREATED, "User A source creation should succeed");
+
+    // User A triggers generation
+    let gen_body = serde_json::json!({ "theme_id": theme_id_a });
+    let (gen_status, gen_resp) = app
+        .post_with_session("/api/v1/syntheses/generate", &gen_body, &session_a)
+        .await;
+    assert_eq!(gen_status, StatusCode::ACCEPTED, "User A generation trigger should return 202");
+    let job_id_a = gen_resp["job_id"].as_str().expect("should have job_id");
+
+    // User B tries to stop User A's job — should return 404 (ownership check)
+    let (stop_status, stop_body) = app
+        .post_with_session(
+            &format!("/api/v1/syntheses/generate/{}/stop", job_id_a),
+            &serde_json::json!({}),
+            &session_b,
+        )
+        .await;
+
+    assert_eq!(
+        stop_status,
+        StatusCode::NOT_FOUND,
+        "User B should not be able to stop User A's job (expected 404)"
+    );
+    assert_eq!(stop_body["error"], "not_found");
+}
diff --git a/backend/tests/pipeline_test.rs b/backend/tests/pipeline_test.rs
index 7b68f8f..6301b88 100644
--- a/backend/tests/pipeline_test.rs
+++ b/backend/tests/pipeline_test.rs
@@ -500,3 +500,212 @@ async fn article_history_dedup_prevents_repeat_articles() {
         "Second run should have history-deduped articles (got 0)"
     );
 }
+
+// ── GAP-08: Preferred source ordering ─────────────────────────────────
+//
+// The pipeline places preferred sources before non-preferred ones in the
+// processing order (`ordered_sources = [preferred, non_preferred].concat()`).
+// Within each wave, articles from preferred source URLs are also placed first
+// before being shuffled independently within their group (preferred_urls and
+// other_urls are each shuffled separately).
+//
+// Deterministic ordering at the individual article level cannot be guaranteed
+// because articles within the preferred group are randomly shuffled.
+//
+// What we can verify deterministically:
+// - With a preferred source and a non-preferred source, both contribute
+//   articles to the synthesis (i.e., preferred ordering does not prevent
+//   non-preferred sources from being processed).
+// - The article_history table records entries from both sources.
+//
+// A test that tries to assert "article from preferred source appears before
+// article from non-preferred source in the synthesis" would be flaky due to
+// the intentional shuffle within each group.
+
+#[tokio::test]
+async fn preferred_sources_processed_first() {
+    let app = common::TestApp::new().await;
+
+    // Set up two source pages on the mock server:
+    // /blog-a (preferred) with /article-pref
+    // /blog-b (non-preferred) with /article-norm
+    let server = wiremock::MockServer::start().await;
+    let base = server.uri();
+
+    // Preferred source page
+    Mock::given(method("GET"))
+        .and(path("/blog-a"))
+        .respond_with(ResponseTemplate::new(200).set_body_string(format!(
+            r#"<html><body><a href="{base}/article-pref">Preferred Article</a></body></html>"#
+        )))
+        .mount(&server)
+        .await;
+
+    // Non-preferred source page
+    Mock::given(method("GET"))
+        .and(path("/blog-b"))
+        .respond_with(ResponseTemplate::new(200).set_body_string(format!(
+            r#"<html><body><a href="{base}/article-norm">Normal Article</a></body></html>"#
+        )))
+        .mount(&server)
+        .await;
+
+    // Article pages
+    Mock::given(method("GET"))
+        .and(path("/article-pref"))
+        .respond_with(ResponseTemplate::new(200).set_body_string(
+            r#"<html><head><title>Preferred Article</title></head>
+            <body><p>This is a preferred article about artificial intelligence research.</p></body></html>"#
+                .to_string(),
+        ))
+        .mount(&server)
+        .await;
+
+    Mock::given(method("GET"))
+        .and(path("/article-norm"))
+        .respond_with(ResponseTemplate::new(200).set_body_string(
+            r#"<html><head><title>Normal Article</title></head>
+            <body><p>This is a normal article about machine learning and AI systems.</p></body></html>"#
+                .to_string(),
+        ))
+        .mount(&server)
+        .await;
+
+    let email = format!("preferred-order-{}@test.com", uuid::Uuid::new_v4());
+    let (user_id, session) = app.create_authenticated_user(&email).await;
+
+    // Create theme
+    let theme_body = serde_json::json!({
+        "name": "Preferred Test Theme",
+        "theme": "Intelligence Artificielle",
+        "categories": ["AI News"],
+        "max_items_per_category": 10,
+        "max_age_days": 365,
+        "summary_length": 1
+    });
+    let (theme_status, theme_resp) = app
+        .post_with_session("/api/v1/themes", &theme_body, &session)
+        .await;
+    assert_eq!(theme_status.as_u16(), 201, "Theme creation should succeed");
+    let theme_id: uuid::Uuid = theme_resp["id"].as_str().unwrap().parse().unwrap();
+
+    // Settings: batch_size=1, source_extraction_window=10 so both sources
+    // are processed in a single wave, article_history_days=0 to disable dedup
+    let settings = serde_json::json!({
+        "max_articles_per_source": 10,
+        "max_links_per_source": 8,
+        "use_brave_search": false,
+        "article_history_days": 0,
+        "batch_size": 1,
+        "source_extraction_window": 10,
+        "search_agent_behavior": "",
+        "ai_provider": "",
+        "ai_model": "",
+        "ai_model_websearch": "",
+        "rate_limit_max_requests": null,
+        "rate_limit_time_window_seconds": null
+    });
+    let (settings_status, _) = app
+        .put_with_session("/api/v1/settings", &settings, &session)
+        .await;
+    assert_eq!(settings_status.as_u16(), 200, "Settings save should succeed");
+
+    // Create source A (will be marked preferred)
+    let source_a_body = serde_json::json!({
+        "title": "Source A (preferred)",
+        "url": format!("{}/blog-a", base),
+        "theme_id": theme_id.to_string()
+    });
+    let (status_a, resp_a) = app
+        .post_with_session("/api/v1/sources", &source_a_body, &session)
+        .await;
+    assert!(status_a.is_success(), "Source A creation should succeed");
+    let source_a_id = resp_a["id"].as_str().expect("Source A should have an id");
+
+    // Create source B (non-preferred)
+    let source_b_body = serde_json::json!({
+        "title": "Source B (normal)",
+        "url": format!("{}/blog-b", base),
+        "theme_id": theme_id.to_string()
+    });
+    let (status_b, _) = app
+        .post_with_session("/api/v1/sources", &source_b_body, &session)
+        .await;
+    assert!(status_b.is_success(), "Source B creation should succeed");
+
+    // Mark source A as preferred
+    let pref_body = serde_json::json!({ "source_ids": [source_a_id] });
+    let (pref_status, _) = app
+        .put_with_session("/api/v1/sources/preferred", &pref_body, &session)
+        .await;
+    assert_eq!(pref_status.as_u16(), 200, "Setting preferred sources should succeed");
+
+    // Run the pipeline
+    let mock_provider = MockLlmProvider::new()
+        .with_default_category("AI News")
+        .into_arc();
+
+    let job_id = uuid::Uuid::new_v4();
+    let (tx, _rx) = make_progress_channel();
+
+    let state = ai_synth_backend::app_state::AppState::new(
+        app.config.clone(),
+        app.pool.clone(),
+        reqwest::Client::new(),
+    );
+
+    let result = synthesis::run_generation_inner(
+        job_id,
+        &state,
+        user_id,
+        theme_id,
+        &tx,
+        Some(mock_provider),
+        &AtomicBool::new(false),
+    )
+    .await;
+
+    assert!(result.is_ok(), "Generation should succeed: {:?}", result.err());
+
+    // Verify both sources contributed articles to article_history.
+    // This confirms the preferred-first ordering does not prevent non-preferred
+    // sources from being processed. Asserting the exact order within the
+    // synthesis is not done here because articles within each group are
+    // randomly shuffled by the pipeline.
+    let used_count: (i64,) = sqlx::query_as(
+        "SELECT COUNT(*) FROM article_history WHERE user_id = $1 AND job_id = $2 AND status = 'used'",
+    )
+    .bind(user_id)
+    .bind(job_id)
+    .fetch_one(&app.pool)
+    .await
+    .unwrap();
+
+    assert!(
+        used_count.0 >= 2,
+        "Both preferred and non-preferred source articles should appear in history (got {})",
+        used_count.0
+    );
+
+    // Verify the synthesis has articles from both sources
+    let synthesis_id = result.unwrap();
+    let row: (serde_json::Value,) =
+        sqlx::query_as("SELECT sections FROM syntheses WHERE id = $1")
+            .bind(synthesis_id)
+            .fetch_one(&app.pool)
+            .await
+            .unwrap();
+
+    let sections: Vec<serde_json::Value> = serde_json::from_value(row.0).unwrap();
+    let total_items: usize = sections
+        .iter()
+        .filter_map(|s| s["items"].as_array())
+        .map(|items| items.len())
+        .sum();
+
+    assert!(
+        total_items >= 2,
+        "Synthesis should contain articles from both sources (got {})",
+        total_items
+    );
+}