1

internal/toolstream/tool_sieve_xml.go

@@ -10,7 +10,7 @@ import (
 
 //nolint:unused // kept as explicit tag inventory for future XML sieve refinements.
 var xmlToolCallClosingTags = []string{"</tool_calls>"}
-var xmlToolCallOpeningTags = []string{"<tool_calls"}
+var xmlToolCallOpeningTags = []string{"<tool_calls", "<invoke"}
 
 // xmlToolCallTagPairs maps each opening tag to its expected closing tag.
 // Order matters: longer/wrapper tags must be checked first.
@@ -24,7 +24,7 @@ var xmlToolCallTagPairs = []struct{ open, close string }{
 var xmlToolCallBlockPattern = regexp.MustCompile(`(?is)(<tool_calls\b[^>]*>\s*(?:.*?)\s*</tool_calls>)`)
 
 // xmlToolTagsToDetect is the set of XML tag prefixes used by findToolSegmentStart.
-var xmlToolTagsToDetect = []string{"<tool_calls>", "<tool_calls\n", "<tool_calls "}
+var xmlToolTagsToDetect = []string{"<tool_calls>", "<tool_calls\n", "<tool_calls ", "<invoke ", "<invoke\n", "<invoke\t", "<invoke\r"}
 
 // consumeXMLToolCapture tries to extract complete XML tool call blocks from captured text.
 func consumeXMLToolCapture(captured string, toolNames []string) (prefix string, calls []toolcall.ParsedToolCall, suffix string, ready bool) {
@@ -55,6 +55,22 @@ func consumeXMLToolCapture(captured string, toolNames []string) (prefix string,
 		// If this block failed to become a tool call, pass it through as text.
 		return prefixPart + xmlBlock, nil, suffixPart, true
 	}
+	if !strings.Contains(lower, "<tool_calls") {
+		invokeIdx := strings.Index(lower, "<invoke")
+		closeIdx := strings.LastIndex(lower, "</tool_calls>")
+		if invokeIdx >= 0 && closeIdx > invokeIdx {
+			closeEnd := closeIdx + len("</tool_calls>")
+			xmlBlock := "<tool_calls>" + captured[invokeIdx:closeIdx] + "</tool_calls>"
+			prefixPart := captured[:invokeIdx]
+			suffixPart := captured[closeEnd:]
+			parsed := toolcall.ParseToolCalls(xmlBlock, toolNames)
+			if len(parsed) > 0 {
+				prefixPart, suffixPart = trimWrappingJSONFence(prefixPart, suffixPart)
+				return prefixPart, parsed, suffixPart, true
+			}
+			return prefixPart + captured[invokeIdx:closeEnd], nil, suffixPart, true
+		}
+	}
 	return "", nil, "", false
 }
 

internal/toolstream/tool_sieve_xml_test.go

@@ -288,6 +288,7 @@ func TestFindToolSegmentStartDetectsXMLToolCalls(t *testing.T) {
 		want  int
 	}{
 		{"tool_calls_tag", "some text <tool_calls>\n", 10},
+		{"invoke_tag_missing_wrapper", "some text <invoke name=\"read_file\">\n", 10},
 		{"bare_tool_call_text", "prefix <tool_call>\n", -1},
 		{"xml_inside_code_fence", "```xml\n<tool_calls><invoke name=\"read_file\"></invoke></tool_calls>\n```", -1},
 		{"no_xml", "just plain text", -1},
@@ -310,6 +311,7 @@ func TestFindPartialXMLToolTagStart(t *testing.T) {
 		want  int
 	}{
 		{"partial_tool_calls", "Hello <tool_ca", 6},
+		{"partial_invoke", "Hello <inv", 6},
 		{"bare_tool_call_not_held", "Hello <tool_name", -1},
 		{"partial_lt_only", "Text <", 5},
 		{"complete_tag", "Text <tool_calls>done", -1},
@@ -505,3 +507,32 @@ func TestProcessToolSievePassesThroughBareToolCallAsText(t *testing.T) {
 		t.Fatalf("expected bare invoke to pass through unchanged, got %q", textContent.String())
 	}
 }
+
+func TestProcessToolSieveRepairsMissingOpeningWrapperWithoutLeakingInvokeText(t *testing.T) {
+	var state State
+	chunks := []string{
+		"<invoke name=\"read_file\">\n",
+		"  <parameter name=\"path\">README.md</parameter>\n",
+		"</invoke>\n",
+		"</tool_calls>",
+	}
+	var events []Event
+	for _, c := range chunks {
+		events = append(events, ProcessChunk(&state, c, []string{"read_file"})...)
+	}
+	events = append(events, Flush(&state, []string{"read_file"})...)
+
+	var textContent strings.Builder
+	toolCalls := 0
+	for _, evt := range events {
+		textContent.WriteString(evt.Content)
+		toolCalls += len(evt.ToolCalls)
+	}
+
+	if toolCalls != 1 {
+		t.Fatalf("expected repaired missing-wrapper stream to emit one tool call, got %d events=%#v", toolCalls, events)
+	}
+	if strings.Contains(textContent.String(), "<invoke") || strings.Contains(textContent.String(), "</tool_calls>") {
+		t.Fatalf("expected repaired missing-wrapper stream not to leak xml text, got %q", textContent.String())
+	}
+}