1 files changed, 48 insertions, 0 deletions
diff --git a/src/compaction.zig b/src/compaction.zig
new file mode 100644
index 0000000..a1f6e89
--- /dev/null
+++ b/src/compaction.zig
@@ -0,0 +1,48 @@
+//! The builtin `/compact` slash command.
+//!
+//! Folds the conversation's older turns into a summary (via
+//! `Agent.compact`), persists the result to the session log, and reports
+//! the outcome to the user. Registered into the CLI's command registry by
+//! `register`.
+
+const std = @import("std");
+const panto = @import("panto");
+const command = @import("command.zig");
+const session_persist = @import("session_persist.zig");
+
+/// Install the `/compact` command into `registry`.
+pub fn register(registry: *command.Registry) !void {
+    try registry.register(.{
+        .name = "compact",
+        .description = "Summarize older turns to free up context. Optional args become extra compaction instructions.",
+        .run = run,
+    });
+}
+
+/// `/compact [extra instructions]` — compact the conversation now.
+fn run(args: []const u8, ctx: *command.Context) anyerror!void {
+    const extra: ?[]const u8 = if (args.len > 0) args else null;
+
+    const res = ctx.agent.compact(ctx.conv, ctx.compaction_prompt, extra) catch |err| {
+        try ctx.stdout.print("\n[compaction failed: {s}]\n> ", .{@errorName(err)});
+        try ctx.stdout_file.flush();
+        return;
+    };
+
+    if (res.compacted) {
+        try session_persist.persistCompaction(
+            ctx.allocator,
+            ctx.session_mgr,
+            ctx.conv,
+            ctx.provider_name,
+            ctx.model_name,
+        );
+        try ctx.stdout.print(
+            "\n[compacted: summarized {d} message(s), kept {d} recent turn(s)]\n> ",
+            .{ res.summarized_messages, res.kept_turns },
+        );
+    } else {
+        try ctx.stdout.writeAll("\n[nothing to compact: conversation already fits]\n> ");
+    }
+    try ctx.stdout_file.flush();
+}