diff --git a/crates/gateway/src/main.rs b/crates/gateway/src/main.rs
index a88aa38..e44a7a4 100644
--- a/crates/gateway/src/main.rs
+++ b/crates/gateway/src/main.rs
@@ -68,6 +68,27 @@ async fn main() {
     let access = access::AccessControl::new(config.auth.enabled);
     access.register_defaults().await;
 
+    // Phase 42 — file-backed truth rules. Probes the `truth/` directory
+    // at repo root (or $LAKEHOUSE_TRUTH_DIR override) and logs how many
+    // rules load. Current request paths still build their own stores
+    // via truth::default_truth_store() / truth::sql_query_guard_store();
+    // the composed-at-boot store gets plumbed through V1State in a
+    // follow-up. This boot probe catches parse errors + duplicate-ID
+    // collisions early rather than at first request.
+    {
+        let truth_dir = std::env::var("LAKEHOUSE_TRUTH_DIR")
+            .unwrap_or_else(|_| "/home/profit/lakehouse/truth".to_string());
+        if std::path::Path::new(&truth_dir).exists() {
+            let mut probe_store = truth::default_truth_store();
+            match truth::loader::load_from_dir(&mut probe_store, &truth_dir) {
+                Ok(n) => tracing::info!("truth: loaded {n} file-backed rule(s) from {truth_dir}"),
+                Err(e) => tracing::warn!("truth: failed to load rules from {truth_dir}: {e}"),
+            }
+        } else {
+            tracing::debug!("truth: no rule dir at {truth_dir}, skipping file-backed load");
+        }
+    }
+
     // Workspace manager for agent-specific overlays
     let workspace_mgr = queryd::workspace::WorkspaceManager::new(store.clone());
     if let Err(e) = workspace_mgr.rebuild().await {