diff --git a/internal/handlers/stack.go b/internal/handlers/stack.go
index d2bc2c65..297cbfd0 100644
--- a/internal/handlers/stack.go
+++ b/internal/handlers/stack.go
@@ -1265,30 +1265,38 @@ func (h *StackHandler) UpdateEnv(c *fiber.Ctx) error {
 		"keys_deleted": deletes,
 		"total_after":  len(merged),
 	})
-	go func(teamID uuid.UUID, stackID uuid.UUID, slug string, meta []byte) {
+	// safego.Go (not a bare `go func`) so a panic in the audit insert is
+	// recovered instead of crashing the worker goroutine / process — matches
+	// the runStackDeploy/runStackRedeploy launches in this file.
+	safego.Go("stack.env.audit", func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 		defer cancel()
 		if aErr := models.InsertAuditEvent(ctx, h.db, models.AuditEvent{
-			TeamID:       teamID,
+			TeamID:       team.ID,
 			Actor:        auditActorSystem,
 			Kind:         "stack.env.updated",
 			ResourceType: "stack",
-			ResourceID:   uuid.NullUUID{UUID: stackID, Valid: true},
+			ResourceID:   uuid.NullUUID{UUID: stack.ID, Valid: true},
 			Summary:      "updated env vars on stack <code>" + slug + "</code>",
-			Metadata:     meta,
+			Metadata:     auditMeta,
 		}); aErr != nil {
 			slog.Warn("stack.env.audit_failed",
-				"error", aErr, "team_id", teamID, "stack_id", stackID, "slug", slug)
+				"error", aErr, "team_id", team.ID, "stack_id", stack.ID, "slug", slug)
 		}
-	}(team.ID, stack.ID, slug, auditMeta)
+	})
 
 	slog.Info("stack.env.updated",
 		"slug", slug, "team_id", team.ID, "stack_id", stack.ID,
 		"keys_set", len(body.Env)-deletes, "keys_deleted", deletes, "total_after", len(merged))
 
 	return c.JSON(fiber.Map{
-		"ok":      true,
-		"env":     merged,
+		"ok": true,
+		// Redact outbound env vars — mirrors DeployHandler.UpdateEnv and
+		// GET /deploy/:id. The stored value (persisted above) is the
+		// unredacted merged map; only the response JSON is masked so
+		// secrets carried over from earlier PATCHes never echo in cleartext
+		// into proxy logs / agent transcripts.
+		"env":     redactEnvVars(merged),
 		"message": "Env vars persisted. Call POST /stacks/" + slug + "/redeploy to apply.",
 	})
 }
diff --git a/internal/handlers/stack_env_persist_test.go b/internal/handlers/stack_env_persist_test.go
index fdb95d5d..003c25ce 100644
--- a/internal/handlers/stack_env_persist_test.go
+++ b/internal/handlers/stack_env_persist_test.go
@@ -119,10 +119,14 @@ func TestStack_PatchEnv_PersistsAndReturns(t *testing.T) {
 		}
 		require.NoError(t, json.NewDecoder(resp.Body).Decode(&body))
 		assert.True(t, body.OK)
+		// The RESPONSE redacts secret-bearing values (bug bash #1): DATABASE_URL
+		// (key contains "URL") is masked to "***", while a non-secret key like
+		// NODE_ENV passes through. The STORED value stays unredacted — asserted
+		// against the DB below. This mirrors DeployHandler.UpdateEnv.
 		assert.Equal(t, map[string]string{
-			"DATABASE_URL": "postgres://example",
+			"DATABASE_URL": "***",
 			"NODE_ENV":     "production",
-		}, body.Env, "response carries the merged env")
+		}, body.Env, "response masks secret values but keeps non-secret keys")
 
 		// DB round-trip — pre-fix this would still be `{}` because the
 		// handler dropped the payload. With migration 062 + UpdateStackEnvVars