fix(providers): extract tool calls from text-based format

src/Netclaw.Daemon.Tests/Configuration/OpenAiCompatibleChatClientTests.cs

@@ -202,6 +202,43 @@ await client.GetResponseAsync(
         Assert.Contains("\"role\":\"tool\"", body, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public async Task ExtractsToolCalls_FromTextBasedFormat_WhenModelSkipsStructuredFormat()
+    {
+        var textWithToolCall = """
+            Let me save that for you.
+            <tool_call>
+            <function=store_memory>
+            <parameter=Content>Important note</parameter>
+            <parameter=Domain>project:test</parameter>
+            </function>
+            </tool_call>
+            """;
+
+        var responseJson = $"{{\"id\":\"1\",\"model\":\"test\",\"choices\":[{{\"finish_reason\":\"stop\",\"message\":{{\"role\":\"assistant\",\"content\":{System.Text.Json.JsonSerializer.Serialize(textWithToolCall)}}}}}]}}";
+
+        using var handler = new RecordingHandler(_ => new HttpResponseMessage(HttpStatusCode.OK)
+        {
+            Content = new StringContent(responseJson, Encoding.UTF8, "application/json")
+        });
+        using var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost:8000") };
+        var endpoint = OpenAiCompatibleEndpoint.FromBaseUrl("http://localhost:8000");
+        var client = new OpenAiCompatibleChatClient(httpClient, endpoint, "test-model");
+
+        var response = await client.GetResponseAsync([new ChatMessage(ChatRole.User, "save this")]);
+
+        var toolCall = Assert.Single(response.Messages[^1].Contents.OfType<FunctionCallContent>());
+        Assert.Equal("store_memory", toolCall.Name);
+        Assert.Equal("Important note", toolCall.Arguments!["Content"]?.ToString());
+        Assert.Equal("project:test", toolCall.Arguments!["Domain"]?.ToString());
+        Assert.Equal(ChatFinishReason.ToolCalls, response.FinishReason);
+
+        var remainingText = response.Messages[^1].Contents.OfType<TextContent>().FirstOrDefault();
+        Assert.NotNull(remainingText);
+        Assert.Contains("Let me save that", remainingText.Text);
+        Assert.DoesNotContain("<tool_call>", remainingText.Text);
+    }
+
     private sealed class RecordingHandler : HttpMessageHandler
     {
         private readonly Func<HttpRequestMessage, HttpResponseMessage> _handler;

src/Netclaw.OpenAICompatible/OpenAiCompatibleChatClient.cs

@@ -54,23 +54,53 @@ public async IAsyncEnumerable<ChatResponseUpdate> GetStreamingResponseAsync(
         await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
         using var reader = new StreamReader(stream, Encoding.UTF8);
         var pendingToolCalls = new Dictionary<int, PendingToolCall>();
+        var accumulatedText = new StringBuilder();
+        var hadStructuredToolCalls = false;
+        ChatResponseUpdate? finalUpdate = null;
 
         while (!cancellationToken.IsCancellationRequested)
         {
             var line = await reader.ReadLineAsync(cancellationToken);
             if (line is null)
-                yield break;
+                break;
 
             if (string.IsNullOrWhiteSpace(line) || !line.StartsWith("data:", StringComparison.Ordinal))
                 continue;
 
             var ssePayload = line[5..].Trim();
             if (ssePayload == "[DONE]")
-                yield break;
+                break;
 
             using var document = JsonDocument.Parse(ssePayload);
             foreach (var update in ParseStreamingUpdates(document.RootElement, pendingToolCalls))
+            {
+                foreach (var tc in update.Contents.OfType<TextContent>())
+                    accumulatedText.Append(tc.Text);
+
+                if (update.Contents.OfType<FunctionCallContent>().Any())
+                    hadStructuredToolCalls = true;
+
+                if (update.FinishReason is not null)
+                    finalUpdate = update;
+
                 yield return update;
+            }
+        }
+
+        // Fallback: if the model stopped without structured tool calls but the text
+        // contains XML-like tool call blocks, emit a synthetic tool call update.
+        if (!hadStructuredToolCalls
+            && finalUpdate?.FinishReason != ChatFinishReason.ToolCalls
+            && accumulatedText.Length > 0)
+        {
+            var textToolCalls = TextToolCallParser.ExtractFromText(accumulatedText.ToString());
+            if (textToolCalls.Count > 0)
+            {
+                yield return new ChatResponseUpdate(ChatRole.Assistant, textToolCalls.Cast<AIContent>().ToList())
+                {
+                    FinishReason = ChatFinishReason.ToolCalls
+                };
+            }
         }
     }
 
@@ -251,6 +281,7 @@ private static ChatResponse ParseChatResponse(JsonElement root)
         var choice = root.GetProperty("choices")[0];
         var message = choice.GetProperty("message");
         var contents = new List<AIContent>();
+        var finishReason = ParseFinishReason(choice);
 
         if (message.TryGetProperty("reasoning_content", out var reasoning)
             && reasoning.ValueKind == JsonValueKind.String)
@@ -264,11 +295,27 @@ private static ChatResponse ParseChatResponse(JsonElement root)
             contents.Add(new TextContent(content.GetString()!));
         }
 
+        // Fallback: extract tool calls from text when model uses XML-like format
+        if (finishReason != ChatFinishReason.ToolCalls)
+        {
+            var textContent = content.ValueKind == JsonValueKind.String ? content.GetString() : null;
+            var textToolCalls = TextToolCallParser.ExtractFromText(textContent);
+            if (textToolCalls.Count > 0)
+            {
+                contents.RemoveAll(c => c is TextContent);
+                var cleaned = TextToolCallParser.StripToolCallText(textContent!);
+                if (!string.IsNullOrWhiteSpace(cleaned))
+                    contents.Add(new TextContent(cleaned));
+                contents.AddRange(textToolCalls);
+                finishReason = ChatFinishReason.ToolCalls;
+            }
+        }
+
         return new ChatResponse(new ChatMessage(ChatRole.Assistant, contents))
         {
             ModelId = root.TryGetProperty("model", out var model) ? model.GetString() : null,
             ResponseId = root.TryGetProperty("id", out var id) ? id.GetString() : null,
-            FinishReason = ParseFinishReason(choice)
+            FinishReason = finishReason
         };
     }
 

src/Netclaw.OpenAICompatible/TextToolCallParser.cs

@@ -0,0 +1,69 @@
+using System.Text.RegularExpressions;
+using Microsoft.Extensions.AI;
+
+namespace Netclaw.OpenAICompatible;
+
+/// <summary>
+/// Extracts structured tool calls from LLM text responses when the model emits
+/// tool calls as text (e.g. Qwen3.5's XML-like format) instead of using the
+/// OpenAI-structured tool_calls response field.
+/// </summary>
+internal static partial class TextToolCallParser
+{
+    /// <summary>
+    /// Attempts to extract tool calls from a text string.
+    /// Returns an empty list if no text-based tool calls are found.
+    /// </summary>
+    public static List<FunctionCallContent> ExtractFromText(string? text)
+    {
+        if (string.IsNullOrWhiteSpace(text))
+            return [];
+
+        var results = new List<FunctionCallContent>();
+
+        foreach (Match block in ToolCallBlockRegex().Matches(text))
+        {
+            var functionMatch = FunctionNameRegex().Match(block.Value);
+            if (!functionMatch.Success)
+                continue;
+
+            var functionName = functionMatch.Groups[1].Value;
+            var arguments = new Dictionary<string, object?>();
+
+            foreach (Match param in ParameterRegex().Matches(block.Value))
+            {
+                arguments[param.Groups[1].Value] = param.Groups[2].Value.Trim();
+            }
+
+            results.Add(new FunctionCallContent(
+                Guid.NewGuid().ToString("N"),
+                functionName,
+                arguments));
+        }
+
+        return results;
+    }
+
+    /// <summary>
+    /// Removes text-based tool call blocks from the text, returning
+    /// the remaining content (if any).
+    /// </summary>
+    public static string StripToolCallText(string text)
+    {
+        return ToolCallBlockRegex().Replace(text, "").Trim();
+    }
+
+    // Matches the entire <tool_call>...</tool_call> block
+    [GeneratedRegex(@"<tool_call>\s*<function=([^>]+)>\s*(.*?)\s*</function>\s*</tool_call>",
+        RegexOptions.Singleline | RegexOptions.Compiled)]
+    private static partial Regex ToolCallBlockRegex();
+
+    // Extracts the function name from <function=NAME>
+    [GeneratedRegex(@"<function=([^>]+)>", RegexOptions.Compiled)]
+    private static partial Regex FunctionNameRegex();
+
+    // Extracts parameter name and value from <parameter=KEY>VALUE</parameter>
+    [GeneratedRegex(@"<parameter=([^>]+)>(.*?)</parameter>",
+        RegexOptions.Singleline | RegexOptions.Compiled)]
+    private static partial Regex ParameterRegex();
+}