diff --git a/crates/kebab-app/tests/ingest_file.rs b/crates/kebab-app/tests/ingest_file.rs
new file mode 100644
index 0000000..b70fa4d
--- /dev/null
+++ b/crates/kebab-app/tests/ingest_file.rs
@@ -0,0 +1,89 @@
+//! Integration: kebab_app::ingest_file_with_config copies external file
+//! to _external/, ingests as single asset, idempotent on second call.
+
+use std::fs;
+
+use kebab_config::Config;
+
+#[test]
+fn ingest_file_copies_external_md_and_reports_new() {
+    let dir = tempfile::tempdir().unwrap();
+    let workspace = dir.path().join("notes");
+    let data = dir.path().join("data");
+    fs::create_dir_all(&workspace).unwrap();
+    fs::create_dir_all(&data).unwrap();
+
+    let mut cfg = Config::defaults();
+    cfg.workspace.root = workspace.to_string_lossy().into_owned();
+    cfg.storage.data_dir = data.to_string_lossy().into_owned();
+    cfg.models.embedding.provider = "none".to_string();
+    cfg.models.embedding.dimensions = 0;
+
+    // Source file outside the workspace.
+    let external_src = dir.path().join("source.md");
+    fs::write(&external_src, "# Hello\n\nbody.").unwrap();
+
+    let report = kebab_app::ingest_file_with_config(cfg.clone(), &external_src).unwrap();
+    assert_eq!(report.scanned, 1, "{report:?}");
+    assert_eq!(report.new, 1, "{report:?}");
+    assert_eq!(report.unchanged, 0, "{report:?}");
+
+    // _external/ dir created, file copied with hash prefix.
+    let ext_dir = workspace.join("_external");
+    assert!(ext_dir.is_dir());
+    let entries: Vec<_> = fs::read_dir(&ext_dir)
+        .unwrap()
+        .filter_map(|e| e.ok())
+        .collect();
+    assert_eq!(entries.len(), 1, "exactly one file in _external/");
+    let name = entries[0].file_name().to_string_lossy().into_owned();
+    assert!(name.ends_with(".md"));
+
+    // .kebabignore has _external/ line.
+    let ki = fs::read_to_string(workspace.join(".kebabignore")).unwrap();
+    assert!(ki.lines().any(|l| l.trim() == "_external/"));
+}
+
+#[test]
+fn ingest_file_idempotent_on_second_call() {
+    let dir = tempfile::tempdir().unwrap();
+    let workspace = dir.path().join("notes");
+    let data = dir.path().join("data");
+    fs::create_dir_all(&workspace).unwrap();
+    fs::create_dir_all(&data).unwrap();
+
+    let mut cfg = Config::defaults();
+    cfg.workspace.root = workspace.to_string_lossy().into_owned();
+    cfg.storage.data_dir = data.to_string_lossy().into_owned();
+    cfg.models.embedding.provider = "none".to_string();
+    cfg.models.embedding.dimensions = 0;
+
+    let src = dir.path().join("doc.md");
+    fs::write(&src, "# A\n\nbody.").unwrap();
+
+    let r1 = kebab_app::ingest_file_with_config(cfg.clone(), &src).unwrap();
+    assert_eq!(r1.new, 1);
+
+    let r2 = kebab_app::ingest_file_with_config(cfg.clone(), &src).unwrap();
+    assert_eq!(r2.new, 0, "{r2:?}");
+    assert_eq!(r2.unchanged, 1, "{r2:?}");
+}
+
+#[test]
+fn ingest_file_errors_on_missing_path() {
+    let dir = tempfile::tempdir().unwrap();
+    let workspace = dir.path().join("notes");
+    let data = dir.path().join("data");
+    fs::create_dir_all(&workspace).unwrap();
+    fs::create_dir_all(&data).unwrap();
+
+    let mut cfg = Config::defaults();
+    cfg.workspace.root = workspace.to_string_lossy().into_owned();
+    cfg.storage.data_dir = data.to_string_lossy().into_owned();
+    cfg.models.embedding.provider = "none".to_string();
+    cfg.models.embedding.dimensions = 0;
+
+    let nonexistent = dir.path().join("nope.md");
+    let err = kebab_app::ingest_file_with_config(cfg, &nonexistent).unwrap_err();
+    assert!(err.to_string().contains("does not exist"), "{err}");
+}