fix ag-ui error

src/Plugins/BotSharp.Plugin.AgUi/Controllers/AgUiController.cs

@@ -18,6 +18,7 @@
 using System.Text;
 using System.Text.Encodings.Web;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using System.Threading.Tasks;
 
 namespace BotSharp.Plugin.AgUi.Controllers;
@@ -37,10 +38,11 @@ public AgUiController(ILogger<AgUiController> logger, IServiceProvider services)
         _options = new JsonSerializerOptions
         {
             PropertyNameCaseInsensitive = true,
-            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
-            WriteIndented = true,
+            PropertyNamingPolicy = null, // Use [JsonPropertyName] attributes for snake_case naming (AG UI protocol requirement)
+            WriteIndented = false, // SSE format should be compact, not indented
             AllowTrailingCommas = true,
-            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
+            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
         };
     }
 
@@ -148,6 +150,11 @@ public async Task Chat([FromBody] AgUiMessageInput input)
                 conv.States.SetState("ag_ui_tools", toolsJson);
             }
 
+            // AG-UI Protocol: First event MUST be RUN_STARTED
+            var runId = input.RunId ?? Guid.NewGuid().ToString();
+            var threadId = input.ThreadId ?? conversationId;
+            await SendRunStartedEvent(outputStream, threadId, runId);
+
             // Send state snapshot if state exists
             if (input.State != null && input.State.Any())
             {
@@ -166,14 +173,38 @@ await conv.SendMessage(
             var finalState = new Dictionary<string, object>();
             foreach (var state in conv.States.GetStates())
             {
-                finalState[state.Key] = state.Value ?? string.Empty;
+                // Try to parse JSON strings back to objects/arrays for proper client-side handling
+                var value = state.Value ?? string.Empty;
+                try
+                {
+                    // If the value looks like JSON, try to deserialize it
+                    if (value is string strValue && 
+                        (strValue.StartsWith("{") || strValue.StartsWith("[")))
+                    {
+                        using var doc = JsonDocument.Parse(strValue);
+                        finalState[state.Key] = doc.RootElement.Clone();
+                    }
+                    else
+                    {
+                        finalState[state.Key] = value;
+                    }
+                }
+                catch
+                {
+                    // If parsing fails, use the value as-is
+                    finalState[state.Key] = value;
+                }
             }
             await SendStateSnapshotEvent(outputStream, finalState);
+
+            // AG-UI Protocol: Last event MUST be RUN_FINISHED
+            await SendRunFinishedEvent(outputStream, threadId, runId);
         }
         catch (Exception ex)
         {
             _logger.LogError(ex, "Error processing AG-UI chat request");
-            await SendErrorEvent(outputStream, ex.Message);
+            // AG-UI Protocol: Send RUN_ERROR on exception
+            await SendRunErrorEvent(outputStream, ex.Message, ex.GetType().Name);
         }
         finally
         {
@@ -279,9 +310,12 @@ private async Task SendToolResultEvent(Stream outputStream, string toolCallId, s
 
     private async Task SendStateSnapshotEvent(Stream outputStream, Dictionary<string, object> state)
     {
+        // Ensure state is not null and properly structured
+        var snapshot = state ?? new Dictionary<string, object>();
+
         var stateEvent = new StateSnapshotEvent
         {
-            Snapshot = state
+            Snapshot = snapshot
         };
         await SendEvent(outputStream, stateEvent);
     }
@@ -296,9 +330,42 @@ private async Task SendErrorEvent(Stream outputStream, string errorMessage)
         await SendEvent(outputStream, errorEvent);
     }
 
+    private async Task SendRunStartedEvent(Stream outputStream, string threadId, string runId)
+    {
+        var runStartedEvent = new RunStartedEvent
+        {
+            ThreadId = threadId,
+            RunId = runId
+        };
+        await SendEvent(outputStream, runStartedEvent);
+    }
+
+    private async Task SendRunFinishedEvent(Stream outputStream, string threadId, string runId)
+    {
+        var runFinishedEvent = new RunFinishedEvent
+        {
+            ThreadId = threadId,
+            RunId = runId
+        };
+        await SendEvent(outputStream, runFinishedEvent);
+    }
+
+    private async Task SendRunErrorEvent(Stream outputStream, string message, string code)
+    {
+        var runErrorEvent = new RunErrorEvent
+        {
+            Message = message,
+            Code = code
+        };
+        await SendEvent(outputStream, runErrorEvent);
+    }
+
     private async Task SendEvent(Stream outputStream, AgUiEvent eventData)
     {
         var json = JsonSerializer.Serialize(eventData, eventData.GetType(), _options);
+
+        // Log the actual JSON being sent for debugging
+        _logger.LogDebug("[AG-UI SSE] Sending event: {Json}", json);
 
         var buffer = Encoding.UTF8.GetBytes($"data: {json}\n\n");
         await outputStream.WriteAsync(buffer, 0, buffer.Length);

src/Plugins/BotSharp.Plugin.AgUi/Models/AgUiEvent.cs

@@ -25,7 +25,7 @@ public TextMessageStartEvent()
     [JsonPropertyName("role")]
     public string Role { get; set; } = "assistant";
 
-    [JsonPropertyName("message_id")]
+    [JsonPropertyName("messageId")]
     public string MessageId { get; set; } = string.Empty;
 }
 
@@ -39,7 +39,7 @@ public TextMessageContentEvent()
         Type = AgUiEventType.TextMessageContent;
     }
 
-    [JsonPropertyName("message_id")]
+    [JsonPropertyName("messageId")]
     public string MessageId { get; set; } = string.Empty;
 
     [JsonPropertyName("delta")]
@@ -56,7 +56,7 @@ public TextMessageEndEvent()
         Type = AgUiEventType.TextMessageEnd;
     }
 
-    [JsonPropertyName("message_id")]
+    [JsonPropertyName("messageId")]
     public string MessageId { get; set; } = string.Empty;
 }
 
@@ -129,7 +129,8 @@ public ToolCallResultEvent()
 }
 
 /// <summary>
-/// State snapshot event
+/// State snapshot event - provides complete state snapshot
+/// The snapshot can contain nested objects, arrays, and primitive values
 /// </summary>
 public class StateSnapshotEvent : AgUiEvent
 {
@@ -138,8 +139,13 @@ public StateSnapshotEvent()
         Type = AgUiEventType.StateSnapshot;
     }
 
+    /// <summary>
+    /// Complete state snapshot as a plain object/dictionary
+    /// Can contain nested objects, arrays, strings, numbers, booleans, and null
+    /// Must be JSON-serializable for proper client-side processing
+    /// </summary>
     [JsonPropertyName("snapshot")]
-    public Dictionary<string, object> Snapshot { get; set; } = new();
+    public object Snapshot { get; set; } = new Dictionary<string, object>();
 }
 
 /// <summary>
@@ -175,3 +181,54 @@ public ErrorEvent()
     [JsonPropertyName("message")]
     public string Message { get; set; } = string.Empty;
 }
+
+/// <summary>
+/// Run started event - MUST be the first event in AG-UI protocol
+/// </summary>
+public class RunStartedEvent : AgUiEvent
+{
+    public RunStartedEvent()
+    {
+        Type = AgUiEventType.RunStarted;
+    }
+
+    [JsonPropertyName("threadId")]
+    public string ThreadId { get; set; } = string.Empty;
+
+    [JsonPropertyName("runId")]
+    public string RunId { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// Run finished event - MUST be the last event in AG-UI protocol
+/// </summary>
+public class RunFinishedEvent : AgUiEvent
+{
+    public RunFinishedEvent()
+    {
+        Type = AgUiEventType.RunFinished;
+    }
+
+    [JsonPropertyName("threadId")]
+    public string ThreadId { get; set; } = string.Empty;
+
+    [JsonPropertyName("runId")]
+    public string RunId { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// Run error event - sent when an error occurs during the run
+/// </summary>
+public class RunErrorEvent : AgUiEvent
+{
+    public RunErrorEvent()
+    {
+        Type = AgUiEventType.RunError;
+    }
+
+    [JsonPropertyName("message")]
+    public string Message { get; set; } = string.Empty;
+
+    [JsonPropertyName("code")]
+    public string Code { get; set; } = string.Empty;
+}

src/Plugins/BotSharp.Plugin.AgUi/Models/AgUiEventType.cs

@@ -1,23 +1,39 @@
 namespace BotSharp.Plugin.AgUi.Models;
 
 /// <summary>
-/// AG-UI protocol event types
+/// AG-UI protocol event types (SCREAMING_SNAKE_CASE format as per AG UI protocol standard)
 /// </summary>
 public static class AgUiEventType
 {
-    public const string TextMessageStart = "text_message_start";
-    public const string TextMessageContent = "text_message_content";
-    public const string TextMessageEnd = "text_message_end";
+    // Text message events
+    public const string TextMessageStart = "TEXT_MESSAGE_START";
+    public const string TextMessageContent = "TEXT_MESSAGE_CONTENT";
+    public const string TextMessageEnd = "TEXT_MESSAGE_END";
+    public const string TextMessageChunk = "TEXT_MESSAGE_CHUNK";
 
-    public const string ToolCallStart = "tool_call_start";
-    public const string ToolCallArgs = "tool_call_args";
-    public const string ToolCallEnd = "tool_call_end";
+    // Tool call events
+    public const string ToolCallStart = "TOOL_CALL_START";
+    public const string ToolCallArgs = "TOOL_CALL_ARGS";
+    public const string ToolCallEnd = "TOOL_CALL_END";
+    public const string ToolCallChunk = "TOOL_CALL_CHUNK";
+    public const string ToolCallResult = "TOOL_CALL_RESULT";
 
-    public const string ToolCallResult = "tool_call_result";
+    // State management events
+    public const string StateSnapshot = "STATE_SNAPSHOT";
+    public const string StateDelta = "STATE_DELTA";
+    public const string MessagesSnapshot = "MESSAGES_SNAPSHOT";
 
-    public const string StateSnapshot = "state_snapshot";
+    // Special events
+    public const string Raw = "RAW";
+    public const string Custom = "CUSTOM";
 
-    public const string Custom = "custom";
+    // Lifecycle events
+    public const string RunStarted = "RUN_STARTED";
+    public const string RunFinished = "RUN_FINISHED";
+    public const string RunError = "RUN_ERROR";
+    public const string StepStarted = "STEP_STARTED";
+    public const string StepFinished = "STEP_FINISHED";
 
-    public const string Error = "error";
+    // Error event
+    public const string Error = "ERROR";
 }

src/Plugins/BotSharp.Plugin.AgUi/ViewModels/AgUiMessageInput.cs

@@ -15,6 +15,12 @@ public class AgUiMessageInput
     [JsonPropertyName("conversation_id")]
     public string? ConversationId { get; set; }
 
+    [JsonPropertyName("threadId")]
+    public string? ThreadId { get; set; }
+
+    [JsonPropertyName("runId")]
+    public string? RunId { get; set; }
+
     [JsonPropertyName("messages")]
     public List<AgUiMessage> Messages { get; set; } = new();