1 files changed, 37 insertions, 0 deletions
diff --git a/src/Agent.App/Logging/JsonLinesRuntimeObserver.cs b/src/Agent.App/Logging/JsonLinesRuntimeObserver.cs
new file mode 100644
index 0000000..b7cbd26
--- /dev/null
+++ b/src/Agent.App/Logging/JsonLinesRuntimeObserver.cs
@@ -0,0 +1,37 @@
+using System.Text.Json;
+using Agent.Core.Ollama;
+using Agent.Core.Runtime;
+using Agent.Core.Tools;
+
+namespace Agent.App.Logging;
+
+public sealed class JsonLinesRuntimeObserver(string logDirectory) : IAgentRuntimeObserver
+{
+    private readonly object _sync = new();
+    private readonly string _path = Path.Combine(logDirectory, "llm.jsonl");
+
+    public void LlmRequest(Guid taskId, int iteration, IReadOnlyList<OllamaMessage> messages) => Write(new
+    {
+        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.request", iteration,
+        messages = messages.Select(static message => new { message.Role, message.Content, image_count = message.Images?.Count ?? 0, message.ToolName })
+    });
+
+    public void LlmResponse(Guid taskId, int iteration, OllamaResult result) => Write(new
+    {
+        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.response", iteration,
+        result.Content, input_tokens = result.InputTokens, output_tokens = result.OutputTokens,
+        tool_calls = result.ToolCalls?.Select(static call => call.Function.Name).ToArray() ?? []
+    });
+
+    public void ToolResult(Guid taskId, string toolName, ToolExecutionResult result) => Write(new
+    {
+        timestamp = DateTimeOffset.UtcNow, task_id = taskId, event_name = "llm.tool_result", tool_name = toolName,
+        result.Success, result.ExternalEffect, result.Output, result.FailureFingerprint
+    });
+
+    private void Write(object value)
+    {
+        string line = JsonSerializer.Serialize(value);
+        lock (_sync) File.AppendAllText(_path, line + Environment.NewLine);
+    }
+}