1 files changed, 34 insertions, 11 deletions

diff --git a/libpanto/src/conversation.zig b/libpanto/src/conversation.zig
index a436378..1942a0c 100644
--- a/libpanto/src/conversation.zig
+++ b/libpanto/src/conversation.zig
@@ -265,10 +265,24 @@ pub const Conversation = struct {
         });
     }
 
-    pub fn addUserMessage(self: *Conversation, text: []const u8) !void {
-        const tb = try textualBlockFromSlice(self.allocator, text);
+    /// Append a `user`-role message from a slice of content blocks.
+    /// Symmetric with `addAssistantMessage`: ownership of the blocks (and
+    /// every byte they reference) transfers to the conversation; the caller
+    /// must not deinit them after this call. This is the general user-side
+    /// builder — a user turn may carry plain text, multiple text blocks
+    /// (e.g. messages queued while the agent was mid-turn), one or more
+    /// `.ToolResult` blocks, or any mix. For the common single-text case,
+    /// build a one-element `.{ .Text = ... }` slice (see the `addUserText`
+    /// test helpers across the codebase).
+    ///
+    /// Blocks must use this conversation's allocator for any owned bytes,
+    /// since the conversation will free them with that allocator.
+    pub fn addUserMessage(self: *Conversation, blocks: []const ContentBlock) !void {
         var content: std.ArrayList(ContentBlock) = .empty;
-        try content.append(self.allocator, .{ .Text = tb });
+        try content.ensureTotalCapacity(self.allocator, blocks.len);
+        for (blocks) |block| {
+            content.appendAssumeCapacity(block);
+        }
         try self.messages.append(self.allocator, .{
             .role = .user,
             .content = content,
@@ -401,6 +415,15 @@ pub fn activeMessageWindow(messages: []const Message) []const Message {
     return messages;
 }
 
+/// Test helper: append a single-text user message. `addUserMessage` takes
+/// a block slice; this wraps the plain-text case the tests below use.
+fn addUserText(conv: *Conversation, text: []const u8) !void {
+    const tb = try textualBlockFromSlice(conv.allocator, text);
+    var block: ContentBlock = .{ .Text = tb };
+    errdefer block.deinit(conv.allocator);
+    try conv.addUserMessage(&.{block});
+}
+
 test "Conversation - add messages and verify content" {
     const allocator = std.testing.allocator;
 
@@ -408,7 +431,7 @@ test "Conversation - add messages and verify content" {
     defer conv.deinit();
 
     try conv.addSystemMessage("You are a helpful assistant.");
-    try conv.addUserMessage("Hello!");
+    try addUserText(&conv, "Hello!");
     try conv.addAssistantMessage(&.{
         .{ .Text = try textualBlockFromSlice(allocator, "Hi there!") },
     }, null);
@@ -448,7 +471,7 @@ test "Conversation - deinit frees without leaks" {
 
     var conv = Conversation.init(allocator);
     try conv.addSystemMessage("system");
-    try conv.addUserMessage("user message");
+    try addUserText(&conv, "user message");
     try conv.addAssistantMessage(&.{
         .{ .Text = try textualBlockFromSlice(allocator, "response") },
     }, null);
@@ -494,7 +517,7 @@ test "effectiveSystemBlocks - append accumulates in order" {
 
     try conv.addSystemMessage("a");
     try conv.addSystemMessage("b");
-    try conv.addUserMessage("hi");
+    try addUserText(&conv, "hi");
     try conv.addSystemMessage("c");
 
     var blocks = try effectiveSystemBlocks(allocator, conv.messages.items);
@@ -548,7 +571,7 @@ test "addCompactionSummary - sits alone in a user message" {
     var conv = Conversation.init(allocator);
     defer conv.deinit();
 
-    try conv.addUserMessage("hi");
+    try addUserText(&conv, "hi");
     try conv.addCompactionSummary("summary of earlier history");
 
     const m = conv.messages.items[1];
@@ -567,7 +590,7 @@ test "latestCompactionIndex - null when never compacted" {
     defer conv.deinit();
 
     try conv.addSystemMessage("sys");
-    try conv.addUserMessage("hi");
+    try addUserText(&conv, "hi");
     try conv.addAssistantMessage(&.{
         .{ .Text = try textualBlockFromSlice(allocator, "hello") },
     }, null);
@@ -582,11 +605,11 @@ test "latestCompactionIndex - returns the latest summary anchor" {
     defer conv.deinit();
 
     try conv.addSystemMessage("sys");
-    try conv.addUserMessage("old");
+    try addUserText(&conv, "old");
     try conv.addCompactionSummary("S1");
-    try conv.addUserMessage("mid");
+    try addUserText(&conv, "mid");
     try conv.addCompactionSummary("S2"); // index 4
-    try conv.addUserMessage("recent");
+    try addUserText(&conv, "recent");
 
     try std.testing.expectEqual(@as(?usize, 4), latestCompactionIndex(conv.messages.items));
 }