Add agent library

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/agent/result.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package agent
+
+import "go.probo.inc/probo/pkg/llm"
+
+type (
+	Result struct {
+		Messages  []llm.Message
+		Usage     llm.Usage
+		Turns     int
+		LastAgent *Agent
+	}
+)
+
+func (r *Result) FinalMessage() llm.Message {
+	if len(r.Messages) == 0 {
+		return llm.Message{}
+	}
+	return r.Messages[len(r.Messages)-1]
+}