1 files changed, 17 insertions, 1 deletions
diff --git a/libpanto/src/turn_persist.zig b/libpanto/src/turn_persist.zig
index 1dacfec..6d260c8 100644
--- a/libpanto/src/turn_persist.zig
+++ b/libpanto/src/turn_persist.zig
@@ -46,12 +46,28 @@ pub fn persistTurn(
     identity: WireIdentity,
     tools: []const ToolDecl,
 ) !void {
+    return persistRange(alloc, session, conv, start_index, conv.messages.items.len, identity, tools);
+}
+
+/// Persist conversation messages in `[start_index, end_index)`. Like
+/// `persistTurn` but with an explicit upper bound, so an incremental flush can
+/// exclude a trailing not-yet-coherent message (a dangling tool call awaiting
+/// its results) while still committing everything before it.
+pub fn persistRange(
+    alloc: Allocator,
+    session: *Session,
+    conv: *conversation.Conversation,
+    start_index: usize,
+    end_index: usize,
+    identity: WireIdentity,
+    tools: []const ToolDecl,
+) !void {
     var batch: std.ArrayList(PersistentMessage) = .empty;
     defer batch.deinit(alloc);
 
     const all_messages = conv.messages.items;
     var i = start_index;
-    while (i < all_messages.len) : (i += 1) {
+    while (i < end_index) : (i += 1) {
         const msg = &all_messages[i];
         if (msg.role == .assistant and hasToolUseWithoutFollowingResults(conv, i)) {
             continue;