fix: fallback tool calls from thinking on empty output

2026-05-04 08:25:26 +08:00 · 2026-04-26 17:45:12 +08:00
parent e2dfe15f48
commit a505f2cb96
11 changed files with 162 additions and 17 deletions
--- a/docs/prompt-compatibility.md
+++ b/docs/prompt-compatibility.md
@@ -97,7 +97,8 @@ DS2API 当前的核心思路，不是把客户端传来的 `messages`、`tools`
 - `ref_file_ids` 只承载文件引用，不承载普通文本消息。
 - `tools` 不会作为“原生工具 schema”直接下发给下游，而是被改写进 `prompt`。
 - OpenAI Chat / Responses 原生走统一 OpenAI 标准化与 DeepSeek payload 组装；Claude / Gemini 会尽量复用 OpenAI prompt/tool 语义，其中 Gemini 直接复用 `promptcompat.BuildOpenAIPromptForAdapter`，Claude 消息接口在可代理场景会转换为 OpenAI chat 形态再执行。
- 客户端传入的 thinking / reasoning 开关会被归一到下游 `thinking_enabled`。Claude surface 没有 `thinking` 字段时按 Anthropic 语义视为关闭；Gemini `generationConfig.thinkingConfig.thinkingBudget` 会翻译成同一套 thinking 开关；关闭时即使上游返回 `response/thinking_content`，兼容层也不会把它当作可见正文输出。
+- 客户端传入的 thinking / reasoning 开关会被归一到下游 `thinking_enabled`。Gemini `generationConfig.thinkingConfig.thinkingBudget` 会翻译成同一套 thinking 开关；关闭时即使上游返回 `response/thinking_content`，兼容层也不会把它当作可见正文输出。Claude surface 在流式请求且未显式声明 `thinking` 时，仍按 Anthropic 语义默认关闭；但在非流式代理场景，兼容层会内部开启一次下游 thinking，用于捕获“正文为空、工具调用落在 thinking 里”的情况，随后在回包前剥离用户不可见的 thinking block。
+- 对 OpenAI Chat / Responses 的非流式收尾，如果最终可见正文为空，兼容层会优先尝试把思维链中的独立 `<tool_calls>...</tool_calls>` 结构当作真实工具调用解析出来。流式链路也会在收尾阶段做同样的 fallback 检测，但不会因为思维链内容去中途拦截或改写流式输出；thinking / reasoning 增量仍按原样先发，只有在结束收尾时才可能补发最终工具调用结果。只有正文为空且思维链里也没有可执行工具调用时，才继续按空回复错误处理。

 ## 5. prompt 是怎么拼出来的

@@ -147,8 +148,8 @@ DS2API 当前的核心思路，不是把客户端传来的 `messages`、`tools`
 3. 再附上统一的 XML tool call 格式约束。
 4. 把这整段内容并入 system prompt。

-工具调用正例仍只示范 canonical XML：`<tool_calls>` → `<invoke name="...">` → `<parameter name="...">`。
-提示词会额外强调：如果要调用工具，工具块的首个非空白字符必须就是 `<tool_calls>`，不能只输出 `</tool_calls>` 而漏掉 opening tag。
+工具调用正例现在优先示范官方 DSML 风格：`<|DSML|tool_calls>` → `<|DSML|invoke name="...">` → `<|DSML|parameter name="..." string="true|false">`。
+兼容层仍接受旧式纯 `<tool_calls>` wrapper，但提示词会优先要求模型输出官方 DSML 标签，并强调不能只输出 closing wrapper 而漏掉 opening tag。
 正例中的工具名只会来自当前请求实际声明的工具；如果当前请求没有足够的已知工具形态，就省略对应的单工具、多工具或嵌套示例，避免把不可用工具名写进 prompt。
 对执行类工具，脚本内容必须进入执行参数本身：`Bash` / `execute_command` 使用 `command`，`exec_command` 使用 `cmd`；不要把脚本示范成 `path` / `content` 文件写入参数。

--- a/internal/format/openai/render_chat.go
+++ b/internal/format/openai/render_chat.go
@@ -7,7 +7,7 @@ import (
 )

 func BuildChatCompletion(completionID, model, finalPrompt, finalThinking, finalText string, toolNames []string) map[string]any {
-	detected := toolcall.ParseStandaloneToolCallsDetailed(finalText, toolNames)
+	detected := toolcall.ParseAssistantToolCallsDetailed(finalText, finalThinking, toolNames)
 	finishReason := "stop"
 	messageObj := map[string]any{"role": "assistant", "content": finalText}
 	if strings.TrimSpace(finalThinking) != "" {
--- a/internal/format/openai/render_responses.go
+++ b/internal/format/openai/render_responses.go
@@ -12,7 +12,7 @@ import (
 func BuildResponseObject(responseID, model, finalPrompt, finalThinking, finalText string, toolNames []string) map[string]any {
 	// Strict mode: only standalone, structured tool-call payloads are treated
 	// as executable tool calls.
-	detected := toolcall.ParseStandaloneToolCallsDetailed(finalText, toolNames)
+	detected := toolcall.ParseAssistantToolCallsDetailed(finalText, finalThinking, toolNames)
 	exposedOutputText := finalText
 	output := make([]any, 0, 2)
 	if len(detected.Calls) > 0 {
--- a/internal/format/openai/render_test.go
+++ b/internal/format/openai/render_test.go
@@ -67,22 +67,22 @@ func TestBuildResponseObjectReasoningOnlyFallsBackToOutputText(t *testing.T) {
 	}
 }

-func TestBuildResponseObjectIgnoresToolCallFromThinkingChannel(t *testing.T) {
+func TestBuildResponseObjectPromotesToolCallFromThinkingWhenTextEmpty(t *testing.T) {
 	obj := BuildResponseObject(
 		"resp_test",
 		"gpt-4o",
 		"prompt",
-		`{"tool_calls":[{"name":"search","input":{"q":"from-thinking"}}]}`,
+		`<tool_calls><invoke name="search"><parameter name="q">from-thinking</parameter></invoke></tool_calls>`,
 		"",
 		[]string{"search"},
 	)

 	output, _ := obj["output"].([]any)
 	if len(output) != 1 {
-		t.Fatalf("expected one message output item, got %#v", obj["output"])
+		t.Fatalf("expected one output item, got %#v", obj["output"])
 	}
 	first, _ := output[0].(map[string]any)
-	if first["type"] != "message" {
-		t.Fatalf("expected output message, got %#v", first["type"])
+	if first["type"] != "function_call" {
+		t.Fatalf("expected function_call output, got %#v", first["type"])
 	}
 }
--- a/internal/httpapi/openai/chat/chat_stream_runtime.go
+++ b/internal/httpapi/openai/chat/chat_stream_runtime.go
@@ -133,7 +133,7 @@ func (s *chatStreamRuntime) finalize(finishReason string) {
 	finalText := cleanVisibleOutput(s.text.String(), s.stripReferenceMarkers)
 	s.finalThinking = finalThinking
 	s.finalText = finalText
-	detected := toolcall.ParseStandaloneToolCallsDetailed(finalText, s.toolNames)
+	detected := toolcall.ParseAssistantToolCallsDetailed(finalText, finalThinking, s.toolNames)
 	if len(detected.Calls) > 0 && !s.toolCallsDoneEmitted {
 		finishReason = "tool_calls"
 		delta := map[string]any{
--- a/internal/httpapi/openai/chat/handler_chat.go
+++ b/internal/httpapi/openai/chat/handler_chat.go
@@ -15,6 +15,7 @@ import (
 	"ds2api/internal/promptcompat"
 	"ds2api/internal/sse"
 	streamengine "ds2api/internal/stream"
+	"ds2api/internal/toolcall"
 )

 func (h *Handler) ChatCompletions(w http.ResponseWriter, r *http.Request) {
@@ -162,7 +163,8 @@ func (h *Handler) handleNonStream(w http.ResponseWriter, resp *http.Response, co
 	if searchEnabled {
 		finalText = replaceCitationMarkersWithLinks(finalText, result.CitationLinks)
 	}
-	if shouldWriteUpstreamEmptyOutputError(finalText) {
+	detected := toolcall.ParseAssistantToolCallsDetailed(finalText, finalThinking, toolNames)
+	if shouldWriteUpstreamEmptyOutputError(finalText) && len(detected.Calls) == 0 {
 		status, message, code := upstreamEmptyOutputDetail(result.ContentFilter, finalText, finalThinking)
 		if historySession != nil {
 			historySession.error(status, message, code, finalThinking, finalText)
--- a/internal/httpapi/openai/chat/handler_toolcall_test.go
+++ b/internal/httpapi/openai/chat/handler_toolcall_test.go
@@ -142,6 +142,37 @@ func TestHandleNonStreamReturns429WhenUpstreamHasOnlyThinking(t *testing.T) {
 	}
 }

+func TestHandleNonStreamPromotesThinkingToolCallsWhenTextEmpty(t *testing.T) {
+	h := &Handler{}
+	resp := makeSSEHTTPResponse(
+		`data: {"p":"response/thinking_content","v":"<tool_calls><invoke name=\"search\"><parameter name=\"q\">from-thinking</parameter></invoke></tool_calls>"}`,
+		`data: [DONE]`,
+	)
+	rec := httptest.NewRecorder()
+
+	h.handleNonStream(rec, resp, "cid-thinking-tool", "deepseek-v4-pro", "prompt", true, false, []string{"search"}, nil)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200 for thinking tool calls, got %d body=%s", rec.Code, rec.Body.String())
+	}
+	out := decodeJSONBody(t, rec.Body.String())
+	choices, _ := out["choices"].([]any)
+	if len(choices) == 0 {
+		t.Fatalf("expected choices, got %#v", out)
+	}
+	choice, _ := choices[0].(map[string]any)
+	if got := asString(choice["finish_reason"]); got != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls, got %#v", choice["finish_reason"])
+	}
+	message, _ := choice["message"].(map[string]any)
+	toolCalls, _ := message["tool_calls"].([]any)
+	if len(toolCalls) != 1 {
+		t.Fatalf("expected one tool call, got %#v", message["tool_calls"])
+	}
+	if content, exists := message["content"]; !exists || content != nil {
+		t.Fatalf("expected content nil when tool call promoted, got %#v", message["content"])
+	}
+}
+
 func TestHandleStreamToolsPlainTextStreamsBeforeFinish(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
@@ -214,6 +245,43 @@ func TestHandleStreamIncompleteCapturedToolJSONFlushesAsTextOnFinalize(t *testin
 	}
 }

+func TestHandleStreamPromotesThinkingToolCallsOnFinalizeWithoutMidstreamIntercept(t *testing.T) {
+	h := &Handler{}
+	resp := makeSSEHTTPResponse(
+		`data: {"p":"response/thinking_content","v":"<tool_calls><invoke name=\"search\"><parameter name=\"q\">from-thinking</parameter></invoke></tool_calls>"}`,
+		`data: [DONE]`,
+	)
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
+
+	h.handleStream(rec, req, resp, "cid-thinking-stream", "deepseek-v4-pro", "prompt", true, false, []string{"search"}, nil)
+
+	frames, done := parseSSEDataFrames(t, rec.Body.String())
+	if !done {
+		t.Fatalf("expected [DONE], body=%s", rec.Body.String())
+	}
+	if !streamHasToolCallsDelta(frames) {
+		t.Fatalf("expected tool_calls delta from finalize fallback, body=%s", rec.Body.String())
+	}
+	reasoningSeen := false
+	for _, frame := range frames {
+		choices, _ := frame["choices"].([]any)
+		for _, item := range choices {
+			choice, _ := item.(map[string]any)
+			delta, _ := choice["delta"].(map[string]any)
+			if asString(delta["reasoning_content"]) != "" {
+				reasoningSeen = true
+			}
+		}
+	}
+	if !reasoningSeen {
+		t.Fatalf("expected reasoning_content to stream before finalize fallback, body=%s", rec.Body.String())
+	}
+	if streamFinishReason(frames) != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls, body=%s", rec.Body.String())
+	}
+}
+
 func TestHandleStreamEmitsDistinctToolCallIDsAcrossSeparateToolBlocks(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
--- a/internal/httpapi/openai/responses/responses_handler.go
+++ b/internal/httpapi/openai/responses/responses_handler.go
@@ -135,10 +135,10 @@ func (h *Handler) handleResponsesNonStream(w http.ResponseWriter, resp *http.Res
 	if searchEnabled {
 		sanitizedText = replaceCitationMarkersWithLinks(sanitizedText, result.CitationLinks)
 	}
-	if writeUpstreamEmptyOutputError(w, sanitizedText, sanitizedThinking, result.ContentFilter) {
+	textParsed := toolcall.ParseAssistantToolCallsDetailed(sanitizedText, sanitizedThinking, toolNames)
+	if len(textParsed.Calls) == 0 && writeUpstreamEmptyOutputError(w, sanitizedText, sanitizedThinking, result.ContentFilter) {
 		return
 	}
-	textParsed := toolcall.ParseStandaloneToolCallsDetailed(sanitizedText, toolNames)
 	logResponsesToolPolicyRejection(traceID, toolChoice, textParsed, "text")

 	callCount := len(textParsed.Calls)
--- a/internal/httpapi/openai/responses/responses_stream_runtime_core.go
+++ b/internal/httpapi/openai/responses/responses_stream_runtime_core.go
@@ -133,7 +133,7 @@ func (s *responsesStreamRuntime) finalize() {
 		s.processToolStreamEvents(toolstream.Flush(&s.sieve, s.toolNames), true, true)
 	}

-	textParsed := toolcall.ParseStandaloneToolCallsDetailed(finalText, s.toolNames)
+	textParsed := toolcall.ParseAssistantToolCallsDetailed(finalText, finalThinking, s.toolNames)
 	detected := textParsed.Calls
 	s.logToolPolicyRejections(textParsed)

--- a/internal/httpapi/openai/responses/responses_stream_test.go
+++ b/internal/httpapi/openai/responses/responses_stream_test.go
@@ -232,6 +232,39 @@ func TestHandleResponsesStreamFailsWhenUpstreamHasOnlyThinking(t *testing.T) {
 	}
 }

+func TestHandleResponsesStreamPromotesThinkingToolCallsOnFinalizeWithoutMidstreamIntercept(t *testing.T) {
+	h := &Handler{}
+	req := httptest.NewRequest(http.MethodPost, "/v1/responses", nil)
+	rec := httptest.NewRecorder()
+
+	sseLine := func(path, value string) string {
+		b, _ := json.Marshal(map[string]any{
+			"p": path,
+			"v": value,
+		})
+		return "data: " + string(b) + "\n"
+	}
+
+	streamBody := sseLine("response/thinking_content", `<tool_calls><invoke name="read_file"><parameter name="path">README.MD</parameter></invoke></tool_calls>`) + "data: [DONE]\n"
+	resp := &http.Response{
+		StatusCode: http.StatusOK,
+		Body:       io.NopCloser(strings.NewReader(streamBody)),
+	}
+
+	h.handleResponsesStream(rec, req, resp, "owner-a", "resp_test", "deepseek-v4-pro", "prompt", true, false, []string{"read_file"}, promptcompat.DefaultToolChoicePolicy(), "")
+
+	body := rec.Body.String()
+	if !strings.Contains(body, "event: response.reasoning.delta") {
+		t.Fatalf("expected reasoning delta in stream body, got %s", body)
+	}
+	if !strings.Contains(body, "event: response.function_call_arguments.done") {
+		t.Fatalf("expected finalize fallback function call event, got %s", body)
+	}
+	if strings.Contains(body, "event: response.failed") {
+		t.Fatalf("did not expect response.failed, body=%s", body)
+	}
+}
+
 func TestHandleResponsesNonStreamRequiredToolChoiceViolation(t *testing.T) {
 	h := &Handler{}
 	rec := httptest.NewRecorder()
@@ -258,7 +291,7 @@ func TestHandleResponsesNonStreamRequiredToolChoiceViolation(t *testing.T) {
 	}
 }

-func TestHandleResponsesNonStreamRequiredToolChoiceIgnoresThinkingToolPayload(t *testing.T) {
+func TestHandleResponsesNonStreamRequiredToolChoiceIgnoresThinkingToolPayloadWhenTextExists(t *testing.T) {
 	h := &Handler{}
 	rec := httptest.NewRecorder()
 	resp := &http.Response{
@@ -351,6 +384,32 @@ func TestHandleResponsesNonStreamReturns429WhenUpstreamHasOnlyThinking(t *testin
 	}
 }

+func TestHandleResponsesNonStreamPromotesThinkingToolCallsWhenTextEmpty(t *testing.T) {
+	h := &Handler{}
+	rec := httptest.NewRecorder()
+	resp := &http.Response{
+		StatusCode: http.StatusOK,
+		Body: io.NopCloser(strings.NewReader(
+			`data: {"p":"response/thinking_content","v":"<tool_calls><invoke name=\"read_file\"><parameter name=\"path\">README.MD</parameter></invoke></tool_calls>"}` + "\n" +
+				`data: [DONE]` + "\n",
+		)),
+	}
+
+	h.handleResponsesNonStream(rec, resp, "owner-a", "resp_test", "deepseek-v4-pro", "prompt", true, false, []string{"read_file"}, promptcompat.DefaultToolChoicePolicy(), "")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200 for thinking tool calls, got %d body=%s", rec.Code, rec.Body.String())
+	}
+	out := decodeJSONBody(t, rec.Body.String())
+	output, _ := out["output"].([]any)
+	if len(output) != 1 {
+		t.Fatalf("expected one output item, got %#v", out["output"])
+	}
+	first, _ := output[0].(map[string]any)
+	if got := asString(first["type"]); got != "function_call" {
+		t.Fatalf("expected function_call output, got %#v", first["type"])
+	}
+}
+
 func extractSSEEventPayload(body, targetEvent string) (map[string]any, bool) {
 	scanner := bufio.NewScanner(strings.NewReader(body))
 	matched := false
--- a/internal/toolcall/toolcalls_parse.go
+++ b/internal/toolcall/toolcalls_parse.go
@@ -32,6 +32,21 @@ func ParseStandaloneToolCallsDetailed(text string, availableToolNames []string)
 	return parseToolCallsDetailedXMLOnly(text)
 }

+func ParseAssistantToolCallsDetailed(text, thinking string, availableToolNames []string) ToolCallParseResult {
+	textParsed := ParseStandaloneToolCallsDetailed(text, availableToolNames)
+	if len(textParsed.Calls) > 0 {
+		return textParsed
+	}
+	if strings.TrimSpace(text) != "" {
+		return textParsed
+	}
+	thinkingParsed := ParseStandaloneToolCallsDetailed(thinking, availableToolNames)
+	if len(thinkingParsed.Calls) > 0 {
+		return thinkingParsed
+	}
+	return textParsed
+}
+
 func parseToolCallsDetailedXMLOnly(text string) ToolCallParseResult {
 	result := ToolCallParseResult{}
 	trimmed := strings.TrimSpace(text)
@@ -74,7 +89,7 @@ func filterToolCallsDetailed(parsed []ParsedToolCall) ([]ParsedToolCall, []strin

 func looksLikeToolCallSyntax(text string) bool {
 	lower := strings.ToLower(text)
-	return strings.Contains(lower, "<tool_calls")
+	return strings.Contains(lower, "<|dsml|tool_calls") || strings.Contains(lower, "<tool_calls")
 }

 func stripFencedCodeBlocks(text string) string {