1 files changed, 42 insertions, 0 deletions
diff --git a/src/zenserver/sessions/logtemplate.h b/src/zenserver/sessions/logtemplate.h
new file mode 100644
index 000000000..e8b07e63d
--- /dev/null
+++ b/src/zenserver/sessions/logtemplate.h
@@ -0,0 +1,42 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/compactbinary.h>
+#include <zencore/string.h>
+
+#include <string_view>
+
+namespace zen {
+
+/// Render a UE structured-log template (as produced by UE_LOGFMT) against a
+/// fields bag, writing the result into a caller-provided builder. Grammar:
+///
+///   format      := (text | escape | placeholder)*
+///   escape      := '{{' | '}}'                      (non-localized, default)
+///                | '`{' | '`}' | '``'               (localized, $locformat)
+///   placeholder := '{' field_path '}'
+///   field_path  := name ('.' name | '[' digits ']')*
+///   name        := [A-Za-z0-9] [A-Za-z0-9_]*        (leading '_' reserved)
+///
+/// There are NO inline format specs — `{Name:spec}` is not part of the
+/// grammar. Formatting control lives on the value side via nested
+/// objects carrying `$text` / `$format` / `$locformat` (see the value-
+/// rendering rules in logtemplate.cpp).
+///
+/// Missing paths render as empty (UE asserts these at emit time, so in
+/// practice they don't occur; the empty-render is defensive). Unknown
+/// primitive CbField types render as empty.
+///
+/// Typical use: pass an `ExtendableStringBuilder<256>` so typical messages
+/// render on the stack with no heap allocation. The builder is appended to,
+/// not cleared, so callers can compose multiple writes if they want.
+///
+/// @param Template   The format string.
+/// @param Fields     The top-level fields bag referenced by placeholders.
+/// @param Out        Builder to append the rendered text to.
+/// @param Localized  True for $locformat templates (backtick escapes);
+///                   false (default) for the top-level `format` field.
+void RenderLogTemplate(std::string_view Template, CbObjectView Fields, StringBuilderBase& Out, bool Localized = false);
+
+}  // namespace zen