Default to aggressive tool-call interception in mixed/fenced text

internal/adapter/claude/handler_stream_test.go

@@ -358,7 +358,7 @@ func TestHandleClaudeStreamRealtimeToolSafetyAcrossStructuredFormats(t *testing.
 	}
 }
 
-func TestHandleClaudeStreamRealtimeDoesNotStopOnUnclosedFencedToolExample(t *testing.T) {
+func TestHandleClaudeStreamRealtimePromotesUnclosedFencedToolExample(t *testing.T) {
 	h := &Handler{}
 	resp := makeClaudeSSEHTTPResponse(
 		"data: {\"p\":\"response/content\",\"v\":\"Here is an example:\\n```json\\n{\\\"tool_calls\\\":[{\\\"name\\\":\\\"Bash\\\",\\\"input\\\":{\\\"command\\\":\\\"pwd\\\"}}]}\"}",
@@ -371,22 +371,27 @@ func TestHandleClaudeStreamRealtimeDoesNotStopOnUnclosedFencedToolExample(t *tes
 	h.handleClaudeStreamRealtime(rec, req, resp, "claude-sonnet-4-5", []any{map[string]any{"role": "user", "content": "show example only"}}, false, false, []string{"Bash"})
 
 	frames := parseClaudeFrames(t, rec.Body.String())
+	foundToolUse := false
 	for _, f := range findClaudeFrames(frames, "content_block_start") {
 		contentBlock, _ := f.Payload["content_block"].(map[string]any)
 		if contentBlock["type"] == "tool_use" {
-			t.Fatalf("unexpected tool_use for fenced example, body=%s", rec.Body.String())
-		}
-	}
-
-	foundEndTurn := false
-	for _, f := range findClaudeFrames(frames, "message_delta") {
-		delta, _ := f.Payload["delta"].(map[string]any)
-		if delta["stop_reason"] == "end_turn" {
-			foundEndTurn = true
+			foundToolUse = true
 			break
 		}
 	}
-	if !foundEndTurn {
-		t.Fatalf("expected stop_reason=end_turn, body=%s", rec.Body.String())
+	if !foundToolUse {
+		t.Fatalf("expected tool_use for fenced example, body=%s", rec.Body.String())
+	}
+
+	foundToolStop := false
+	for _, f := range findClaudeFrames(frames, "message_delta") {
+		delta, _ := f.Payload["delta"].(map[string]any)
+		if delta["stop_reason"] == "tool_use" {
+			foundToolStop = true
+			break
+		}
+	}
+	if !foundToolStop {
+		t.Fatalf("expected stop_reason=tool_use, body=%s", rec.Body.String())
 	}
 }

internal/adapter/openai/handler_toolcall_test.go

@@ -243,7 +243,7 @@ func TestHandleNonStreamEmbeddedToolCallExamplePromotesToolCall(t *testing.T) {
 	}
 }
 
-func TestHandleNonStreamFencedToolCallExampleNotIntercepted(t *testing.T) {
+func TestHandleNonStreamFencedToolCallExamplePromotesToolCall(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
 		"data: {\"p\":\"response/content\",\"v\":\"```json\\n{\\\"tool_calls\\\":[{\\\"name\\\":\\\"search\\\",\\\"input\\\":{\\\"q\\\":\\\"go\\\"}}]}\\n```\"}",
@@ -259,16 +259,17 @@ func TestHandleNonStreamFencedToolCallExampleNotIntercepted(t *testing.T) {
 	out := decodeJSONBody(t, rec.Body.String())
 	choices, _ := out["choices"].([]any)
 	choice, _ := choices[0].(map[string]any)
-	if choice["finish_reason"] != "stop" {
-		t.Fatalf("expected finish_reason=stop, got %#v", choice["finish_reason"])
+	if choice["finish_reason"] != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls, got %#v", choice["finish_reason"])
 	}
 	msg, _ := choice["message"].(map[string]any)
-	if _, ok := msg["tool_calls"]; ok {
-		t.Fatalf("did not expect tool_calls field for fenced example: %#v", msg["tool_calls"])
+	toolCalls, _ := msg["tool_calls"].([]any)
+	if len(toolCalls) != 1 {
+		t.Fatalf("expected one tool_call field for fenced example: %#v", msg["tool_calls"])
 	}
 	content, _ := msg["content"].(string)
-	if !strings.Contains(content, "```json") || !strings.Contains(content, `"tool_calls"`) {
-		t.Fatalf("expected fenced tool example to pass through as text, got %q", content)
+	if strings.Contains(content, `"tool_calls"`) {
+		t.Fatalf("expected raw tool_calls json stripped from content, got %q", content)
 	}
 }
 
@@ -616,7 +617,7 @@ func TestHandleStreamToolCallWithSameChunkTrailingTextRemainsText(t *testing.T)
 	}
 }
 
-func TestHandleStreamFencedToolCallSnippetRemainsText(t *testing.T) {
+func TestHandleStreamFencedToolCallSnippetPromotesToolCall(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
 		fmt.Sprintf(`data: {"p":"response/content","v":%q}`, "下面是调用示例：\n```json\n"),
@@ -632,8 +633,8 @@ func TestHandleStreamFencedToolCallSnippetRemainsText(t *testing.T) {
 	if !done {
 		t.Fatalf("expected [DONE], body=%s", rec.Body.String())
 	}
-	if streamHasToolCallsDelta(frames) {
-		t.Fatalf("did not expect tool_calls delta for fenced snippet, body=%s", rec.Body.String())
+	if !streamHasToolCallsDelta(frames) {
+		t.Fatalf("expected tool_calls delta for fenced snippet, body=%s", rec.Body.String())
 	}
 	content := strings.Builder{}
 	for _, frame := range frames {
@@ -647,11 +648,11 @@ func TestHandleStreamFencedToolCallSnippetRemainsText(t *testing.T) {
 		}
 	}
 	got := content.String()
-	if !strings.Contains(got, "```json") || !strings.Contains(strings.ToLower(got), "tool_calls") {
-		t.Fatalf("expected fenced tool snippet in content, got=%q", got)
+	if strings.Contains(strings.ToLower(got), "tool_calls") {
+		t.Fatalf("expected raw fenced tool_calls snippet stripped from content, got=%q", got)
 	}
-	if streamFinishReason(frames) != "stop" {
-		t.Fatalf("expected finish_reason=stop, body=%s", rec.Body.String())
+	if streamFinishReason(frames) != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls, body=%s", rec.Body.String())
 	}
 }
 

internal/adapter/openai/tool_sieve_core.go

@@ -168,36 +168,21 @@ func findToolSegmentStart(s string) int {
 	}
 	lower := strings.ToLower(s)
 	keywords := []string{"tool_calls", "function.name:", "[tool_call_history]"}
-	offset := 0
-	for {
-		bestKeyIdx := -1
-		matchedKeyword := ""
-
-		for _, kw := range keywords {
-			idx := strings.Index(lower[offset:], kw)
-			if idx >= 0 {
-				absIdx := offset + idx
-				if bestKeyIdx < 0 || absIdx < bestKeyIdx {
-					bestKeyIdx = absIdx
-					matchedKeyword = kw
-				}
-			}
+	bestKeyIdx := -1
+	for _, kw := range keywords {
+		idx := strings.Index(lower, kw)
+		if idx >= 0 && (bestKeyIdx < 0 || idx < bestKeyIdx) {
+			bestKeyIdx = idx
 		}
-
-		if bestKeyIdx < 0 {
-			return -1
-		}
-
-		keyIdx := bestKeyIdx
-		start := strings.LastIndex(s[:keyIdx], "{")
-		if start < 0 {
-			start = keyIdx
-		}
-		if !insideCodeFence(s[:start]) {
-			return start
-		}
-		offset = keyIdx + len(matchedKeyword)
 	}
+	if bestKeyIdx < 0 {
+		return -1
+	}
+	start := strings.LastIndex(s[:bestKeyIdx], "{")
+	if start < 0 {
+		start = bestKeyIdx
+	}
+	return start
 }
 
 func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix string, calls []util.ParsedToolCall, suffix string, ready bool) {
@@ -229,9 +214,6 @@ func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix
 	}
 	prefixPart := captured[:start]
 	suffixPart := captured[end:]
-	if insideCodeFence(state.recentTextTail + prefixPart) {
-		return captured, nil, "", true
-	}
 	parsed := util.ParseStandaloneToolCallsDetailed(obj, toolNames)
 	if len(parsed.Calls) == 0 {
 		if parsed.SawToolCallSyntax && parsed.RejectedByPolicy {

internal/adapter/openai/tool_sieve_incremental.go

@@ -19,9 +19,6 @@ func buildIncrementalToolDeltas(state *toolStreamSieveState) []toolCallDelta {
 	if start < 0 {
 		return nil
 	}
-	if insideCodeFence(state.recentTextTail + captured[:start]) {
-		return nil
-	}
 	certainSingle, hasMultiple := classifyToolCallsIncrementalSafety(captured, keyIdx)
 	if hasMultiple {
 		state.disableDeltas = true

internal/format/openai/render_test.go

@@ -69,7 +69,7 @@ func TestBuildResponseObjectPromotesMixedProseToolPayloadToFunctionCall(t *testi
 	}
 }
 
-func TestBuildResponseObjectFencedToolPayloadRemainsText(t *testing.T) {
+func TestBuildResponseObjectPromotesFencedToolPayloadToFunctionCall(t *testing.T) {
 	obj := BuildResponseObject(
 		"resp_test",
 		"gpt-4o",
@@ -80,16 +80,16 @@ func TestBuildResponseObjectFencedToolPayloadRemainsText(t *testing.T) {
 	)
 
 	outputText, _ := obj["output_text"].(string)
-	if outputText == "" {
-		t.Fatalf("expected output_text preserved for fenced example")
+	if outputText != "" {
+		t.Fatalf("expected output_text hidden for fenced tool payload, got %q", outputText)
 	}
 	output, _ := obj["output"].([]any)
 	if len(output) != 1 {
-		t.Fatalf("expected one message output item, got %#v", obj["output"])
+		t.Fatalf("expected one function_call output item, got %#v", obj["output"])
 	}
 	first, _ := output[0].(map[string]any)
-	if first["type"] != "message" {
-		t.Fatalf("expected message output type, got %#v", first["type"])
+	if first["type"] != "function_call" {
+		t.Fatalf("expected function_call output type, got %#v", first["type"])
 	}
 }
 

internal/util/toolcalls_parse.go

@@ -26,10 +26,6 @@ func ParseToolCallsDetailed(text string, availableToolNames []string) ToolCallPa
 	if strings.TrimSpace(text) == "" {
 		return result
 	}
-	text = stripFencedCodeBlocks(text)
-	if strings.TrimSpace(text) == "" {
-		return result
-	}
 	result.SawToolCallSyntax = looksLikeToolCallSyntax(text)
 
 	candidates := buildToolCallCandidates(text)
@@ -75,7 +71,7 @@ func ParseStandaloneToolCalls(text string, availableToolNames []string) []Parsed
 
 func ParseStandaloneToolCallsDetailed(text string, availableToolNames []string) ToolCallParseResult {
 	result := ToolCallParseResult{}
-	trimmed := strings.TrimSpace(stripFencedCodeBlocks(text))
+	trimmed := strings.TrimSpace(text)
 	if trimmed == "" {
 		return result
 	}

internal/util/toolcalls_test.go

@@ -22,8 +22,8 @@ func TestParseToolCalls(t *testing.T) {
 func TestParseToolCallsFromFencedJSON(t *testing.T) {
 	text := "I will call tools now\n```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"news\"}}]}\n```"
 	calls := ParseToolCalls(text, []string{"search"})
-	if len(calls) != 0 {
-		t.Fatalf("expected fenced tool_call example to be ignored, got %#v", calls)
+	if len(calls) != 1 {
+		t.Fatalf("expected fenced tool_call payload to be parsed, got %#v", calls)
 	}
 }
 
@@ -112,10 +112,10 @@ func TestParseStandaloneToolCallsSupportsMixedProsePayload(t *testing.T) {
 	}
 }
 
-func TestParseStandaloneToolCallsIgnoresFencedCodeBlock(t *testing.T) {
+func TestParseStandaloneToolCallsParsesFencedCodeBlock(t *testing.T) {
 	fenced := "```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"go\"}}]}\n```"
-	if calls := ParseStandaloneToolCalls(fenced, []string{"search"}); len(calls) != 0 {
-		t.Fatalf("expected fenced tool_call example to be ignored, got %#v", calls)
+	if calls := ParseStandaloneToolCalls(fenced, []string{"search"}); len(calls) != 1 {
+		t.Fatalf("expected fenced tool_call payload to be parsed, got %#v", calls)
 	}
 }
 

internal/util/util_edge_test.go

@@ -409,8 +409,8 @@ func TestParseToolCallsWithFunctionWrapper(t *testing.T) {
 func TestParseStandaloneToolCallsFencedCodeBlock(t *testing.T) {
 	fenced := "Here's an example:\n```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"go\"}}]}\n```\nDon't execute this."
 	calls := ParseStandaloneToolCalls(fenced, []string{"search"})
-	if len(calls) != 0 {
-		t.Fatalf("expected fenced code block ignored, got %d calls", len(calls))
+	if len(calls) != 1 {
+		t.Fatalf("expected fenced code block to be parsed, got %d calls", len(calls))
 	}
 }
 

tests/compat/expected/toolcalls_fenced_json.json

@@ -1,6 +1,13 @@
 {
-  "calls": [],
-  "sawToolCallSyntax": false,
+  "calls": [
+    {
+      "name": "read_file",
+      "input": {
+        "path": "README.MD"
+      }
+    }
+  ],
+  "sawToolCallSyntax": true,
   "rejectedByPolicy": false,
   "rejectedToolNames": []
-}
+}

tests/compat/expected/toolcalls_standalone_fenced_example.json

@@ -1,6 +1,13 @@
 {
-  "calls": [],
-  "sawToolCallSyntax": false,
+  "calls": [
+    {
+      "name": "read_file",
+      "input": {
+        "path": "README.MD"
+      }
+    }
+  ],
+  "sawToolCallSyntax": true,
   "rejectedByPolicy": false,
   "rejectedToolNames": []
-}
+}