diff --git a/rag/04-idioms.md b/rag/04-idioms.md
index 1f6e0ec..8ce59d8 100644
--- a/rag/04-idioms.md
+++ b/rag/04-idioms.md
@@ -180,6 +180,14 @@ Web and worker are **separate binaries** built from explicit file lists.
 - `--module <name>` sets the temp module path (must sit under the app's module so RTL
   packages can import the app's internal packages).
 
+### Safety net: endpoint smoke test
+
+Dynamic typing has no compile-time guarantee, so a smoke test is the practical safety net
+(buy it back at runtime, like Python+pytest). solmade ships `smoke_test.sh`: it mints a
+temp superadmin session in PG, curls each endpoint, and asserts HTTP status + the JSON
+`ok`/shape contract (`./smoke_test.sh` fast; `--full` adds the queue→worker→LLM E2E),
+exiting non-zero on any failure. Run it after any refactor.
+
 Deploy (launchd): `launchctl kickstart -k gui/$(id -u)/kr.solmade.web` (and
 `...worker1/2/3`). The worker build (`build_worker.sh`) links `cmd_prg/job_worker.prg`
 plus the shared `app/lib/*.prg` (so `LLM_CHAT` and prompts are available to it too).