revert: replace fullwidth pipe ｜ with halfwidth | in DSML tool markup

PR #460 introduced fullwidth pipe characters (｜) in DSML tool call formatting
to improve parsing robustness, but models exposed to these fullwidth pipes in
system prompts exhibit significantly higher rates of tool output hallucinations.
Reverting to halfwidth pipes (|) drastically reduces tokenizer/perplexity-driven
hallucinations while retaining the existing confusable-hardening in the parser.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/httpapi/claude/current_input_file_test.go

@@ -93,7 +93,11 @@ func (d *claudeCurrentInputDS) GetPow(context.Context, *auth.RequestAuth, int) (
 
 func (d *claudeCurrentInputDS) UploadFile(_ context.Context, _ *auth.RequestAuth, req dsclient.UploadFileRequest, _ int) (*dsclient.UploadFileResult, error) {
 	d.uploads = append(d.uploads, req)
-	return &dsclient.UploadFileResult{ID: "file-claude-history"}, nil
+	id := "file-claude-history"
+	if len(d.uploads) > 1 {
+		id = "file-claude-tools"
+	}
+	return &dsclient.UploadFileResult{ID: id}, nil
 }
 
 func (d *claudeCurrentInputDS) CallCompletion(_ context.Context, _ *auth.RequestAuth, payload map[string]any, _ string, _ int) (*http.Response, error) {
@@ -156,3 +160,47 @@ func TestClaudeDirectAppliesCurrentInputFile(t *testing.T) {
 		t.Fatalf("expected persisted message to match upstream continuation prompt, got %#v", full.Messages)
 	}
 }
+
+func TestClaudeCurrentInputFileUploadsToolsSeparately(t *testing.T) {
+	ds := &claudeCurrentInputDS{}
+	h := &Handler{
+		Store: mockClaudeConfig{aliases: map[string]string{"claude-sonnet-4-6": "deepseek-v4-flash"}},
+		Auth:  claudeCurrentInputAuth{},
+		DS:    ds,
+	}
+	reqBody := `{"model":"claude-sonnet-4-6","messages":[{"role":"user","content":"hello from claude"}],"tools":[{"name":"search","description":"Search docs","input_schema":{"type":"object"}}],"max_tokens":1024}`
+	req := httptest.NewRequest(http.MethodPost, "/v1/messages", strings.NewReader(reqBody))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+
+	h.Messages(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+	}
+	if len(ds.uploads) != 2 {
+		t.Fatalf("expected history and tools uploads, got %d", len(ds.uploads))
+	}
+	if ds.uploads[0].Filename != "DS2API_HISTORY.txt" || ds.uploads[1].Filename != "DS2API_TOOLS.txt" {
+		t.Fatalf("unexpected upload filenames: %#v", ds.uploads)
+	}
+	historyText := string(ds.uploads[0].Data)
+	if strings.Contains(historyText, "You have access to these tools") || strings.Contains(historyText, "Description: Search docs") {
+		t.Fatalf("history transcript should not embed tool descriptions, got %q", historyText)
+	}
+	toolsText := string(ds.uploads[1].Data)
+	if !strings.Contains(toolsText, "# DS2API_TOOLS.txt") || !strings.Contains(toolsText, "Tool: search") || !strings.Contains(toolsText, "Description: Search docs") {
+		t.Fatalf("expected tools transcript to include tool schema, got %q", toolsText)
+	}
+	refIDs, _ := ds.payload["ref_file_ids"].([]any)
+	if len(refIDs) < 2 || refIDs[0] != "file-claude-history" || refIDs[1] != "file-claude-tools" {
+		t.Fatalf("expected history and tools ref ids first, got %#v", ds.payload["ref_file_ids"])
+	}
+	prompt, _ := ds.payload["prompt"].(string)
+	if !strings.Contains(prompt, "DS2API_TOOLS.txt") || !strings.Contains(prompt, "TOOL CALL FORMAT") {
+		t.Fatalf("expected live prompt to reference tools file and retain format instructions, got %q", prompt)
+	}
+	if strings.Contains(prompt, "Description: Search docs") {
+		t.Fatalf("live prompt should not inline tool descriptions, got %q", prompt)
+	}
+}

internal/httpapi/claude/handler_util_test.go

@@ -93,10 +93,10 @@ func TestNormalizeClaudeMessagesToolUseToAssistantToolCalls(t *testing.T) {
 		t.Fatalf("expected call id preserved, got %#v", call)
 	}
 	content, _ := m["content"].(string)
-	if !containsStr(content, "<｜DSML｜tool_calls>") || !containsStr(content, `<｜DSML｜invoke name="search_web">`) {
+	if !containsStr(content, "<|DSML|tool_calls>") || !containsStr(content, `<|DSML|invoke name="search_web">`) {
 		t.Fatalf("expected assistant content to include DSML tool call history, got %q", content)
 	}
-	if !containsStr(content, `<｜DSML｜parameter name="query"><![CDATA[latest]]></｜DSML｜parameter>`) {
+	if !containsStr(content, `<|DSML|parameter name="query"><![CDATA[latest]]></|DSML|parameter>`) {
 		t.Fatalf("expected assistant content to include serialized parameters, got %q", content)
 	}
 }
@@ -133,7 +133,7 @@ func TestNormalizeClaudeMessagesPreservesThinkingOnToolUseHistory(t *testing.T)
 	if !containsStr(prompt, "[reasoning_content]\nneed live search before answering\n[/reasoning_content]") {
 		t.Fatalf("expected thinking in prompt history, got %q", prompt)
 	}
-	if !containsStr(prompt, `<｜DSML｜invoke name="search_web">`) {
+	if !containsStr(prompt, `<|DSML|invoke name="search_web">`) {
 		t.Fatalf("expected tool call in prompt history, got %q", prompt)
 	}
 }
@@ -329,7 +329,7 @@ func TestBuildClaudeToolPromptSingleTool(t *testing.T) {
 	if !containsStr(prompt, "Search the web") {
 		t.Fatalf("expected description in prompt")
 	}
-	if !containsStr(prompt, "<｜DSML｜tool_calls>") {
+	if !containsStr(prompt, "<|DSML|tool_calls>") {
 		t.Fatalf("expected DSML tool_calls format in prompt")
 	}
 	if !containsStr(prompt, "TOOL CALL FORMAT") {

internal/httpapi/claude/standard_request.go

@@ -52,7 +52,7 @@ func normalizeClaudeRequest(store ConfigReader, req map[string]any) (claudeNorma
 			RequestedModel:  strings.TrimSpace(model),
 			ResolvedModel:   dsModel,
 			ResponseModel:   strings.TrimSpace(model),
-			Messages:        payload["messages"].([]any),
+			Messages:        normalizedMessages,
 			PromptTokenText: finalPrompt,
 			ToolsRaw:        toolsRequested,
 			FinalPrompt:     finalPrompt,

internal/httpapi/gemini/convert_messages_test.go

@@ -89,7 +89,7 @@ func TestGeminiMessagesFromRequestPreservesThoughtOnFunctionCallHistory(t *testi
 	if !strings.Contains(prompt, "[reasoning_content]\nneed current state before answering\n[/reasoning_content]") {
 		t.Fatalf("expected thought in prompt history, got %q", prompt)
 	}
-	if !strings.Contains(prompt, `<｜DSML｜invoke name="search_web">`) {
+	if !strings.Contains(prompt, `<|DSML|invoke name="search_web">`) {
 		t.Fatalf("expected tool call in prompt history, got %q", prompt)
 	}
 }

internal/httpapi/gemini/handler_test.go

@@ -67,7 +67,11 @@ func (m *testGeminiDS) GetPow(_ context.Context, _ *auth.RequestAuth, _ int) (st
 //nolint:unused // reserved test double for native Gemini DS-call path coverage.
 func (m *testGeminiDS) UploadFile(_ context.Context, _ *auth.RequestAuth, req dsclient.UploadFileRequest, _ int) (*dsclient.UploadFileResult, error) {
 	m.uploadCalls = append(m.uploadCalls, req)
-	return &dsclient.UploadFileResult{ID: "file-gemini-history"}, nil
+	id := "file-gemini-history"
+	if len(m.uploadCalls) > 1 {
+		id = "file-gemini-tools"
+	}
+	return &dsclient.UploadFileResult{ID: id}, nil
 }
 
 //nolint:unused // reserved test double for native Gemini DS-call path coverage.

internal/httpapi/openai/chat/test_helpers_test.go

@@ -2,6 +2,7 @@ package chat
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"strings"
@@ -148,8 +149,12 @@ func (m *inlineUploadDSStub) UploadFile(ctx context.Context, _ *auth.RequestAuth
 	if m.uploadErr != nil {
 		return nil, m.uploadErr
 	}
+	id := "file-inline-1"
+	if len(m.uploadCalls) > 1 {
+		id = "file-inline-" + fmt.Sprint(len(m.uploadCalls))
+	}
 	return &dsclient.UploadFileResult{
-		ID:       "file-inline-1",
+		ID:       id,
 		Filename: req.Filename,
 		Bytes:    int64(len(req.Data)),
 		Status:   "uploaded",

internal/httpapi/openai/chat/vercel_prepare_test.go

@@ -141,6 +141,71 @@ func TestHandleVercelStreamPrepareAppliesCurrentInputFile(t *testing.T) {
 	}
 }
 
+func TestHandleVercelStreamPrepareUsesHalfwidthDSMLToolPrompt(t *testing.T) {
+	t.Setenv("VERCEL", "1")
+	t.Setenv("DS2API_VERCEL_INTERNAL_SECRET", "stream-secret")
+
+	h := &Handler{
+		Store: mockOpenAIConfig{},
+		Auth:  streamStatusAuthStub{},
+		DS:    &inlineUploadDSStub{},
+	}
+
+	reqBody, _ := json.Marshal(map[string]any{
+		"model": "deepseek-v4-flash",
+		"messages": []any{
+			map[string]any{"role": "user", "content": "search docs"},
+		},
+		"tools": []any{
+			map[string]any{
+				"type": "function",
+				"function": map[string]any{
+					"name":        "search",
+					"description": "search docs",
+					"parameters": map[string]any{
+						"type": "object",
+						"properties": map[string]any{
+							"query": map[string]any{"type": "string"},
+						},
+						"required": []any{"query"},
+					},
+				},
+			},
+		},
+		"stream": true,
+	})
+	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions?__stream_prepare=1", strings.NewReader(string(reqBody)))
+	req.Header.Set("Authorization", "Bearer direct-token")
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Ds2-Internal-Token", "stream-secret")
+	rec := httptest.NewRecorder()
+
+	h.handleVercelStreamPrepare(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+	}
+	var body map[string]any
+	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
+		t.Fatalf("decode failed: %v", err)
+	}
+	finalPrompt, _ := body["final_prompt"].(string)
+	payload, _ := body["payload"].(map[string]any)
+	payloadPrompt, _ := payload["prompt"].(string)
+	for label, promptText := range map[string]string{"final_prompt": finalPrompt, "payload.prompt": payloadPrompt} {
+		if !strings.Contains(promptText, "<|DSML|tool_calls>") || !strings.Contains(promptText, "Tag punctuation alphabet: ASCII < > / = \" plus the halfwidth pipe |.") {
+			t.Fatalf("expected %s to contain halfwidth DSML tool instructions, got %q", label, promptText)
+		}
+		if strings.Contains(promptText, "\uff5c") || strings.Contains(promptText, "full"+"width vertical bar") {
+			t.Fatalf("expected %s not to contain legacy pipe guidance, got %q", label, promptText)
+		}
+	}
+	toolNames, _ := body["tool_names"].([]any)
+	if len(toolNames) != 1 || toolNames[0] != "search" {
+		t.Fatalf("expected prepared tool names to align with request tools, got %#v", body["tool_names"])
+	}
+}
+
 func TestHandleVercelStreamPrepareMapsCurrentInputFileManagedAuthFailureTo401(t *testing.T) {
 	t.Setenv("VERCEL", "1")
 	t.Setenv("DS2API_VERCEL_INTERNAL_SECRET", "stream-secret")

internal/httpapi/openai/deps_injection_test.go

@@ -103,7 +103,7 @@ func TestNormalizeOpenAIResponsesRequestAlwaysAcceptsWideInput(t *testing.T) {
 	if out.Surface != "openai_responses" {
 		t.Fatalf("unexpected surface: %q", out.Surface)
 	}
-	if !strings.Contains(out.FinalPrompt, "<｜User｜>hi") {
+	if !strings.Contains(out.FinalPrompt, "<|User|>hi") {
 		t.Fatalf("unexpected final prompt: %q", out.FinalPrompt)
 	}
 }

internal/httpapi/openai/file_inline_upload_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -41,8 +42,12 @@ func (m *inlineUploadDSStub) UploadFile(ctx context.Context, _ *auth.RequestAuth
 	if m.uploadErr != nil {
 		return nil, m.uploadErr
 	}
+	id := "file-inline-1"
+	if len(m.uploadCalls) > 1 {
+		id = "file-inline-" + fmt.Sprint(len(m.uploadCalls))
+	}
 	return &dsclient.UploadFileResult{
-		ID:       "file-inline-1",
+		ID:       id,
 		Filename: req.Filename,
 		Bytes:    int64(len(req.Data)),
 		Status:   "uploaded",

internal/httpapi/openai/history/current_input_file.go

@@ -15,6 +15,7 @@ import (
 
 const (
 	currentInputFilename    = promptcompat.CurrentInputContextFilename
+	currentToolsFilename    = promptcompat.CurrentToolsContextFilename
 	currentInputContentType = "text/plain; charset=utf-8"
 	currentInputPurpose     = "assistants"
 )
@@ -50,6 +51,7 @@ func (s Service) ApplyCurrentInputFile(ctx context.Context, a *auth.RequestAuth,
 	if strings.TrimSpace(fileText) == "" {
 		return stdReq, errors.New("current user input file produced empty transcript")
 	}
+	toolsText, _ := promptcompat.BuildOpenAIToolsContextTranscript(stdReq.ToolsRaw, stdReq.ToolChoice)
 	modelType := "default"
 	if resolvedType, ok := config.GetModelType(stdReq.ResolvedModel); ok {
 		modelType = resolvedType
@@ -69,21 +71,44 @@ func (s Service) ApplyCurrentInputFile(ctx context.Context, a *auth.RequestAuth,
 		return stdReq, errors.New("upload current user input file returned empty file id")
 	}
 
+	toolFileID := ""
+	if strings.TrimSpace(toolsText) != "" {
+		result, err := s.DS.UploadFile(ctx, a, dsclient.UploadFileRequest{
+			Filename:    currentToolsFilename,
+			ContentType: currentInputContentType,
+			Purpose:     currentInputPurpose,
+			ModelType:   modelType,
+			Data:        []byte(toolsText),
+		}, 3)
+		if err != nil {
+			return stdReq, fmt.Errorf("upload current tools file: %w", err)
+		}
+		toolFileID = strings.TrimSpace(result.ID)
+		if toolFileID == "" {
+			return stdReq, errors.New("upload current tools file returned empty file id")
+		}
+	}
+
 	messages := []any{
 		map[string]any{
 			"role":    "user",
-			"content": currentInputFilePrompt(),
+			"content": currentInputFilePrompt(toolFileID != ""),
 		},
 	}
 
 	stdReq.Messages = messages
 	stdReq.HistoryText = fileText
 	stdReq.CurrentInputFileApplied = true
-	stdReq.RefFileIDs = prependUniqueRefFileID(stdReq.RefFileIDs, fileID)
-	stdReq.FinalPrompt, stdReq.ToolNames = promptcompat.BuildOpenAIPrompt(messages, stdReq.ToolsRaw, "", stdReq.ToolChoice, stdReq.Thinking)
+	stdReq.RefFileIDs = prependUniqueRefFileIDs(stdReq.RefFileIDs, fileID, toolFileID)
+	stdReq.FinalPrompt, stdReq.ToolNames = promptcompat.BuildOpenAIPromptWithToolInstructionsOnly(messages, stdReq.ToolsRaw, "", stdReq.ToolChoice, stdReq.Thinking)
 	// Token accounting must reflect the actual downstream context:
-	// the uploaded DS2API_HISTORY.txt file content + the continuation live prompt.
-	stdReq.PromptTokenText = fileText + "\n" + stdReq.FinalPrompt
+	// uploaded context files + the continuation live prompt.
+	tokenParts := []string{fileText}
+	if strings.TrimSpace(toolsText) != "" {
+		tokenParts = append(tokenParts, toolsText)
+	}
+	tokenParts = append(tokenParts, stdReq.FinalPrompt)
+	stdReq.PromptTokenText = strings.Join(tokenParts, "\n")
 	return stdReq, nil
 }
 
@@ -106,23 +131,40 @@ func latestUserInputForFile(messages []any) (int, string) {
 	return -1, ""
 }
 
-func currentInputFilePrompt() string {
-	return "Continue from the latest state in the attached DS2API_HISTORY.txt context. Treat it as the current working state and answer the latest user request directly."
+func currentInputFilePrompt(hasToolsFile bool) string {
+	prompt := "Continue from the latest state in the attached DS2API_HISTORY.txt context. Treat it as the current working state and answer the latest user request directly."
+	if hasToolsFile {
+		prompt += " Available tool descriptions and parameter schemas are attached in DS2API_TOOLS.txt; use only those tools and follow the tool-call format rules in this prompt."
+	}
+	return prompt
 }
 
-func prependUniqueRefFileID(existing []string, fileID string) []string {
-	fileID = strings.TrimSpace(fileID)
-	if fileID == "" {
-		return existing
-	}
-	out := make([]string, 0, len(existing)+1)
-	out = append(out, fileID)
-	for _, id := range existing {
-		trimmed := strings.TrimSpace(id)
-		if trimmed == "" || strings.EqualFold(trimmed, fileID) {
+func prependUniqueRefFileIDs(existing []string, fileIDs ...string) []string {
+	out := make([]string, 0, len(existing)+len(fileIDs))
+	seen := map[string]struct{}{}
+	for _, fileID := range fileIDs {
+		trimmed := strings.TrimSpace(fileID)
+		if trimmed == "" {
+			continue
+		}
+		key := strings.ToLower(trimmed)
+		if _, ok := seen[key]; ok {
 			continue
 		}
 		out = append(out, trimmed)
+		seen[key] = struct{}{}
+	}
+	for _, id := range existing {
+		trimmed := strings.TrimSpace(id)
+		if trimmed == "" {
+			continue
+		}
+		key := strings.ToLower(trimmed)
+		if _, ok := seen[key]; ok {
+			continue
+		}
+		out = append(out, trimmed)
+		seen[key] = struct{}{}
 	}
 	return out
 }

internal/httpapi/openai/history_split_test.go

@@ -84,7 +84,7 @@ func TestBuildOpenAICurrentInputContextTranscriptUsesNumberedHistorySections(t *
 		"latest user turn",
 		"[reasoning_content]",
 		"hidden reasoning",
-		"<｜DSML｜tool_calls>",
+		"<|DSML|tool_calls>",
 	} {
 		if !strings.Contains(transcript, want) {
 			t.Fatalf("expected transcript to contain %q, got %q", want, transcript)
@@ -380,6 +380,79 @@ func TestApplyCurrentInputFileUploadsFullContextFile(t *testing.T) {
 	}
 }
 
+func TestApplyCurrentInputFileUploadsToolsContextSeparately(t *testing.T) {
+	ds := &inlineUploadDSStub{}
+	h := &openAITestSurface{
+		Store: mockOpenAIConfig{
+			currentInputEnabled: true,
+			currentInputMin:     0,
+		},
+		DS: ds,
+	}
+	req := map[string]any{
+		"model":    "deepseek-v4-flash",
+		"messages": historySplitTestMessages(),
+		"tools": []any{
+			map[string]any{
+				"type": "function",
+				"function": map[string]any{
+					"name":        "search",
+					"description": "search docs",
+					"parameters": map[string]any{
+						"type": "object",
+					},
+				},
+			},
+		},
+	}
+	stdReq, err := promptcompat.NormalizeOpenAIChatRequest(h.Store, req, "")
+	if err != nil {
+		t.Fatalf("normalize failed: %v", err)
+	}
+
+	out, err := h.applyCurrentInputFile(context.Background(), &auth.RequestAuth{DeepSeekToken: "token"}, stdReq)
+	if err != nil {
+		t.Fatalf("apply current input file failed: %v", err)
+	}
+	if len(ds.uploadCalls) != 2 {
+		t.Fatalf("expected history and tools uploads, got %d", len(ds.uploadCalls))
+	}
+	if ds.uploadCalls[0].Filename != "DS2API_HISTORY.txt" {
+		t.Fatalf("expected first upload to be DS2API_HISTORY.txt, got %q", ds.uploadCalls[0].Filename)
+	}
+	if ds.uploadCalls[1].Filename != "DS2API_TOOLS.txt" {
+		t.Fatalf("expected second upload to be DS2API_TOOLS.txt, got %q", ds.uploadCalls[1].Filename)
+	}
+	historyText := string(ds.uploadCalls[0].Data)
+	if strings.Contains(historyText, "You have access to these tools") || strings.Contains(historyText, "Description: search docs") {
+		t.Fatalf("history transcript should not embed tool descriptions, got %q", historyText)
+	}
+	toolsText := string(ds.uploadCalls[1].Data)
+	for _, want := range []string{"# DS2API_TOOLS.txt", "Tool: search", "Description: search docs", `Parameters: {"type":"object"}`} {
+		if !strings.Contains(toolsText, want) {
+			t.Fatalf("expected tools transcript to contain %q, got %q", want, toolsText)
+		}
+	}
+	if strings.Contains(toolsText, "TOOL CALL FORMAT") {
+		t.Fatalf("tools transcript should not duplicate tool format instructions, got %q", toolsText)
+	}
+	if !strings.Contains(out.FinalPrompt, "Continue from the latest state in the attached DS2API_HISTORY.txt context.") || !strings.Contains(out.FinalPrompt, "DS2API_TOOLS.txt") {
+		t.Fatalf("expected live prompt to reference both context files, got %q", out.FinalPrompt)
+	}
+	if !strings.Contains(out.FinalPrompt, "TOOL CALL FORMAT") || !strings.Contains(out.FinalPrompt, "Remember: The ONLY valid way to use tools") {
+		t.Fatalf("expected live prompt to retain tool format instructions, got %q", out.FinalPrompt)
+	}
+	if strings.Contains(out.FinalPrompt, "You have access to these tools") || strings.Contains(out.FinalPrompt, "Description: search docs") || strings.Contains(out.FinalPrompt, "Parameters:") {
+		t.Fatalf("expected live prompt to omit tool descriptions after tools upload, got %q", out.FinalPrompt)
+	}
+	if len(out.RefFileIDs) < 2 || out.RefFileIDs[0] != "file-inline-1" || out.RefFileIDs[1] != "file-inline-2" {
+		t.Fatalf("expected history and tools file ids first, got %#v", out.RefFileIDs)
+	}
+	if !strings.Contains(out.PromptTokenText, "# DS2API_HISTORY.txt") || !strings.Contains(out.PromptTokenText, "# DS2API_TOOLS.txt") || !strings.Contains(out.PromptTokenText, "Description: search docs") {
+		t.Fatalf("expected prompt token text to include uploaded history and tools content, got %q", out.PromptTokenText)
+	}
+}
+
 func TestApplyCurrentInputFileCarriesHistoryText(t *testing.T) {
 	ds := &inlineUploadDSStub{}
 	h := &openAITestSurface{

internal/httpapi/openai/leaked_output_sanitize_test.go

@@ -19,7 +19,7 @@ func TestSanitizeLeakedOutputRemovesLeakedWireToolCallAndResult(t *testing.T) {
 }
 
 func TestSanitizeLeakedOutputRemovesStandaloneMetaMarkers(t *testing.T) {
-	raw := "A<| end_of_sentence |><| Assistant |>B<| end_of_thinking |>C<｜end▁of▁thinking｜>D<｜end▁of▁sentence｜>E<| end_of_toolresults |>F<｜end▁of▁instructions｜>G"
+	raw := "A<| end_of_sentence |><| Assistant |>B<| end_of_thinking |>C<|end▁of▁thinking|>D<|end▁of▁sentence|>E<| end_of_toolresults |>F<|end▁of▁instructions|>G"
 	got := sanitizeLeakedOutput(raw)
 	if got != "ABCDEFG" {
 		t.Fatalf("unexpected sanitize result for meta markers: %q", got)
@@ -27,7 +27,7 @@ func TestSanitizeLeakedOutputRemovesStandaloneMetaMarkers(t *testing.T) {
 }
 
 func TestSanitizeLeakedOutputRemovesThinkAndBosMarkers(t *testing.T) {
-	raw := "A<think>B</think>C<｜begin▁of▁sentence｜>D<| begin_of_sentence |>E<｜begin_of_sentence｜>F"
+	raw := "A<think>B</think>C<|begin▁of▁sentence|>D<| begin_of_sentence |>E<|begin_of_sentence|>F"
 	got := sanitizeLeakedOutput(raw)
 	if got != "ABCDEF" {
 		t.Fatalf("unexpected sanitize result for think/BOS markers: %q", got)
@@ -35,7 +35,7 @@ func TestSanitizeLeakedOutputRemovesThinkAndBosMarkers(t *testing.T) {
 }
 
 func TestSanitizeLeakedOutputRemovesThoughtMarkers(t *testing.T) {
-	raw := "A<｜▁of▁thought｜>B<| of_thought |>C<| begin_of_thought |>D<| end_of_thought |>E"
+	raw := "A<|▁of▁thought|>B<| of_thought |>C<| begin_of_thought |>D<| end_of_thought |>E"
 	got := sanitizeLeakedOutput(raw)
 	if got != "ABCDE" {
 		t.Fatalf("unexpected sanitize result for leaked thought markers: %q", got)
@@ -51,7 +51,7 @@ func TestSanitizeLeakedOutputRemovesDanglingThinkBlock(t *testing.T) {
 }
 
 func TestSanitizeLeakedOutputRemovesCompleteDSMLToolCallWrapper(t *testing.T) {
-	raw := "前置文本\n<｜DSML｜tool_calls>\n<｜DSML｜invoke name=\"Bash\">\n<｜DSML｜parameter name=\"command\"></｜DSML｜parameter>\n</｜DSML｜invoke>\n</｜DSML｜tool_calls>\n后置文本"
+	raw := "前置文本\n<|DSML|tool_calls>\n<|DSML|invoke name=\"Bash\">\n<|DSML|parameter name=\"command\"></|DSML|parameter>\n</|DSML|invoke>\n</|DSML|tool_calls>\n后置文本"
 	got := sanitizeLeakedOutput(raw)
 	if got != "前置文本\n\n后置文本" {
 		t.Fatalf("unexpected sanitize result for leaked dsml wrapper: %q", got)

internal/httpapi/openai/shared/leaked_output_sanitize.go

@@ -14,20 +14,20 @@ var leakedToolResultBlobPattern = regexp.MustCompile(`(?is)<\s*\|\s*tool\s*\|\s*
 var leakedThinkTagPattern = regexp.MustCompile(`(?is)</?\s*think\s*>`)
 
 // leakedBOSMarkerPattern matches DeepSeek BOS markers in BOTH forms:
-//   - ASCII underscore: <｜begin_of_sentence｜>
-//   - U+2581 variant:   <｜begin▁of▁sentence｜>
-var leakedBOSMarkerPattern = regexp.MustCompile(`(?i)<[｜\|]\s*begin[_▁]of[_▁]sentence\s*[｜\|]>`)
+//   - ASCII underscore: <|begin_of_sentence|>
+//   - U+2581 variant:   <|begin▁of▁sentence|>
+var leakedBOSMarkerPattern = regexp.MustCompile(`(?i)<[|\|]\s*begin[_▁]of[_▁]sentence\s*[|\|]>`)
 
 // leakedThoughtMarkerPattern matches leaked thought control markers in both
 // explicit and compact forms:
 //   - ASCII underscore: <| of_thought |>, <| begin_of_thought |>
-//   - U+2581 variant:   <｜▁of▁thought｜>, <｜begin▁of▁thought｜>
-var leakedThoughtMarkerPattern = regexp.MustCompile(`(?i)<[｜\|]\s*(?:begin[_▁])?[_▁]*of[_▁]thought\s*[｜\|]>`)
+//   - U+2581 variant:   <|▁of▁thought|>, <|begin▁of▁thought|>
+var leakedThoughtMarkerPattern = regexp.MustCompile(`(?i)<[|\|]\s*(?:begin[_▁])?[_▁]*of[_▁]thought\s*[|\|]>`)
 
 // leakedMetaMarkerPattern matches the remaining DeepSeek special tokens in BOTH forms:
-//   - ASCII underscore: <｜end_of_sentence｜>, <｜end_of_toolresults｜>, <｜end_of_instructions｜>
-//   - U+2581 variant:   <｜end▁of▁sentence｜>, <｜end▁of▁toolresults｜>, <｜end▁of▁instructions｜>
-var leakedMetaMarkerPattern = regexp.MustCompile(`(?i)<[｜\|]\s*(?:assistant|tool|end[_▁]of[_▁]sentence|end[_▁]of[_▁]thinking|end[_▁]of[_▁]thought|end[_▁]of[_▁]toolresults|end[_▁]of[_▁]instructions)\s*[｜\|]>`)
+//   - ASCII underscore: <|end_of_sentence|>, <|end_of_toolresults|>, <|end_of_instructions|>
+//   - U+2581 variant:   <|end▁of▁sentence|>, <|end▁of▁toolresults|>, <|end▁of▁instructions|>
+var leakedMetaMarkerPattern = regexp.MustCompile(`(?i)<[|\|]\s*(?:assistant|tool|end[_▁]of[_▁]sentence|end[_▁]of[_▁]thinking|end[_▁]of[_▁]thought|end[_▁]of[_▁]toolresults|end[_▁]of[_▁]instructions)\s*[|\|]>`)
 
 // leakedAgentXMLBlockPatterns catch agent-style XML blocks that leak through
 // when the sieve fails to capture them. These are applied only to complete