refactor: remove legacy TOOL_CALL_HISTORY/TOOL_RESULT_HISTORY markers and consolidate tool call formatting into a new prompt package

internal/adapter/claude/handler_util_test.go

@@ -93,8 +93,11 @@ func TestNormalizeClaudeMessagesToolUseToAssistantToolCalls(t *testing.T) {
 		t.Fatalf("expected call id preserved, got %#v", call)
 	}
 	content, _ := m["content"].(string)
-	if !containsStr(content, "search_web") || !containsStr(content, `"arguments":"{\"query\":\"latest\"}"`) {
-		t.Fatalf("expected assistant content to include serialized tool call for prompt roundtrip, got %q", content)
+	if !containsStr(content, "<tool_calls>") || !containsStr(content, "<tool_name>search_web</tool_name>") {
+		t.Fatalf("expected assistant content to include XML tool call history, got %q", content)
+	}
+	if !containsStr(content, `<parameters>{"query":"latest"}</parameters>`) {
+		t.Fatalf("expected assistant content to include serialized parameters, got %q", content)
 	}
 }
 
@@ -251,9 +254,6 @@ func TestBuildClaudeToolPromptSingleTool(t *testing.T) {
 	if !containsStr(prompt, "<tool_calls>") {
 		t.Fatalf("expected XML tool_calls format in prompt")
 	}
-	if containsStr(prompt, "TOOL_CALL_HISTORY") || containsStr(prompt, "TOOL_RESULT_HISTORY") {
-		t.Fatalf("expected legacy tool history markers removed from prompt")
-	}
 	if !containsStr(prompt, "TOOL CALL FORMAT") {
 		t.Fatalf("expected tool call format header in prompt")
 	}

internal/adapter/claude/handler_utils.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"ds2api/internal/prompt"
 	"ds2api/internal/util"
 )
 
@@ -153,7 +154,7 @@ func normalizeClaudeToolUseToAssistant(block map[string]any) map[string]any {
 	}
 	return map[string]any{
 		"role":       "assistant",
-		"content":    marshalCompactJSON(toolCalls),
+		"content":    prompt.FormatToolCallsForPrompt(toolCalls),
 		"tool_calls": toolCalls,
 	}
 }

internal/adapter/openai/message_normalize.go

@@ -1,7 +1,6 @@
 package openai
 
 import (
-	"encoding/json"
 	"strings"
 
 	"ds2api/internal/prompt"
@@ -55,7 +54,18 @@ func normalizeOpenAIMessagesForPrompt(raw []any, traceID string) []map[string]an
 }
 
 func buildAssistantContentForPrompt(msg map[string]any) string {
-	return strings.TrimSpace(normalizeOpenAIContentForPrompt(msg["content"]))
+	content := strings.TrimSpace(normalizeOpenAIContentForPrompt(msg["content"]))
+	toolHistory := prompt.FormatToolCallsForPrompt(msg["tool_calls"])
+	switch {
+	case content == "" && toolHistory == "":
+		return ""
+	case content == "":
+		return toolHistory
+	case toolHistory == "":
+		return content
+	default:
+		return content + "\n\n" + toolHistory
+	}
 }
 
 func buildToolContentForPrompt(msg map[string]any) string {
@@ -70,18 +80,6 @@ func normalizeOpenAIContentForPrompt(v any) string {
 	return prompt.NormalizeContent(v)
 }
 
-func normalizeToolArgumentString(raw string) string {
-	trimmed := strings.TrimSpace(raw)
-	if trimmed == "" {
-		return ""
-	}
-	if looksLikeConcatenatedJSON(trimmed) {
-		// Keep original payload to avoid silent argument rewrites.
-		return raw
-	}
-	return trimmed
-}
-
 func normalizeOpenAIRoleForPrompt(role string) string {
 	role = strings.ToLower(strings.TrimSpace(role))
 	if role == "developer" {
@@ -96,20 +94,3 @@ func asString(v any) string {
 	}
 	return ""
 }
-
-func looksLikeConcatenatedJSON(raw string) bool {
-	trimmed := strings.TrimSpace(raw)
-	if trimmed == "" {
-		return false
-	}
-	if strings.Contains(trimmed, "}{") || strings.Contains(trimmed, "][") {
-		return true
-	}
-	dec := json.NewDecoder(strings.NewReader(trimmed))
-	var first any
-	if err := dec.Decode(&first); err != nil {
-		return false
-	}
-	var second any
-	return dec.Decode(&second) == nil
-}

internal/adapter/openai/message_normalize_test.go

@@ -34,20 +34,23 @@ func TestNormalizeOpenAIMessagesForPrompt_AssistantToolCallsAndToolResult(t *tes
 	}
 
 	normalized := normalizeOpenAIMessagesForPrompt(raw, "")
-	if len(normalized) != 3 {
-		t.Fatalf("expected 3 normalized messages with tool-call-only assistant turn omitted, got %d", len(normalized))
+	if len(normalized) != 4 {
+		t.Fatalf("expected 4 normalized messages with assistant tool history preserved, got %d", len(normalized))
 	}
-	toolContent, _ := normalized[2]["content"].(string)
-	if !strings.Contains(toolContent, `"temp":18`) {
-		t.Fatalf("tool result should be transparently forwarded, got %q", toolContent)
+	assistantContent, _ := normalized[2]["content"].(string)
+	if !strings.Contains(assistantContent, "<tool_calls>") {
+		t.Fatalf("assistant tool history should be preserved in XML form, got %q", assistantContent)
 	}
-	if strings.Contains(toolContent, "[TOOL_RESULT_HISTORY]") {
-		t.Fatalf("tool history marker should not be injected: %q", toolContent)
+	if !strings.Contains(assistantContent, "<tool_name>get_weather</tool_name>") {
+		t.Fatalf("expected tool name in preserved history, got %q", assistantContent)
+	}
+	if !strings.Contains(normalized[3]["content"].(string), `"temp":18`) {
+		t.Fatalf("tool result should be transparently forwarded, got %#v", normalized[3]["content"])
 	}
 
 	prompt := util.MessagesPrepare(normalized)
-	if strings.Contains(prompt, "[TOOL_CALL_HISTORY]") || strings.Contains(prompt, "[TOOL_RESULT_HISTORY]") {
-		t.Fatalf("expected no synthetic history markers in prompt: %q", prompt)
+	if !strings.Contains(prompt, "<tool_calls>") {
+		t.Fatalf("expected preserved assistant tool history in prompt: %q", prompt)
 	}
 }
 
@@ -170,8 +173,15 @@ func TestNormalizeOpenAIMessagesForPrompt_AssistantMultipleToolCallsRemainSepara
 	}
 
 	normalized := normalizeOpenAIMessagesForPrompt(raw, "")
-	if len(normalized) != 0 {
-		t.Fatalf("expected assistant tool_call-only message omitted, got %#v", normalized)
+	if len(normalized) != 1 {
+		t.Fatalf("expected assistant tool_call-only message preserved, got %#v", normalized)
+	}
+	content, _ := normalized[0]["content"].(string)
+	if strings.Count(content, "<tool_call>") != 2 {
+		t.Fatalf("expected two preserved tool call blocks, got %q", content)
+	}
+	if !strings.Contains(content, "<tool_name>search_web</tool_name>") || !strings.Contains(content, "<tool_name>eval_javascript</tool_name>") {
+		t.Fatalf("expected both tool names in preserved history, got %q", content)
 	}
 }
 
@@ -192,8 +202,12 @@ func TestNormalizeOpenAIMessagesForPrompt_PreservesConcatenatedToolArguments(t *
 	}
 
 	normalized := normalizeOpenAIMessagesForPrompt(raw, "")
-	if len(normalized) != 0 {
-		t.Fatalf("expected assistant tool_call-only content omitted, got %#v", normalized)
+	if len(normalized) != 1 {
+		t.Fatalf("expected assistant tool_call-only content preserved, got %#v", normalized)
+	}
+	content, _ := normalized[0]["content"].(string)
+	if !strings.Contains(content, `{}{"query":"测试工具调用"}`) {
+		t.Fatalf("expected concatenated tool arguments preserved, got %q", content)
 	}
 }
 
@@ -215,7 +229,7 @@ func TestNormalizeOpenAIMessagesForPrompt_AssistantToolCallsMissingNameAreDroppe
 
 	normalized := normalizeOpenAIMessagesForPrompt(raw, "")
 	if len(normalized) != 0 {
-		t.Fatalf("expected assistant tool_calls without text omitted, got %#v", normalized)
+		t.Fatalf("expected assistant tool_calls without text to be dropped when name is missing, got %#v", normalized)
 	}
 }
 
@@ -237,8 +251,15 @@ func TestNormalizeOpenAIMessagesForPrompt_AssistantNilContentDoesNotInjectNullLi
 	}
 
 	normalized := normalizeOpenAIMessagesForPrompt(raw, "")
-	if len(normalized) != 0 {
-		t.Fatalf("expected nil-content assistant tool_call-only message omitted, got %#v", normalized)
+	if len(normalized) != 1 {
+		t.Fatalf("expected nil-content assistant tool_call-only message preserved, got %#v", normalized)
+	}
+	content, _ := normalized[0]["content"].(string)
+	if strings.Contains(content, "null") {
+		t.Fatalf("expected no null literal injection, got %q", content)
+	}
+	if !strings.Contains(content, "<tool_calls>") {
+		t.Fatalf("expected assistant tool history in normalized content, got %q", content)
 	}
 }
 

internal/adapter/openai/prompt_build_test.go

@@ -47,8 +47,11 @@ func TestBuildOpenAIFinalPrompt_HandlerPathIncludesToolRoundtripSemantics(t *tes
 	if !strings.Contains(finalPrompt, `"condition":"sunny"`) {
 		t.Fatalf("handler finalPrompt should preserve tool output content: %q", finalPrompt)
 	}
-	if strings.Contains(finalPrompt, "[TOOL_CALL_HISTORY]") || strings.Contains(finalPrompt, "[TOOL_RESULT_HISTORY]") {
-		t.Fatalf("handler finalPrompt should not include synthetic history markers: %q", finalPrompt)
+	if !strings.Contains(finalPrompt, "<tool_calls>") {
+		t.Fatalf("handler finalPrompt should preserve assistant tool history: %q", finalPrompt)
+	}
+	if !strings.Contains(finalPrompt, "<tool_name>get_weather</tool_name>") {
+		t.Fatalf("handler finalPrompt should include tool name history: %q", finalPrompt)
 	}
 }
 

internal/adapter/openai/responses_input_items.go

@@ -1,11 +1,11 @@
 package openai
 
 import (
-	"encoding/json"
 	"fmt"
 	"strings"
 
 	"ds2api/internal/config"
+	"ds2api/internal/prompt"
 )
 
 func normalizeResponsesInputItem(m map[string]any) map[string]any {
@@ -148,7 +148,7 @@ func normalizeResponsesInputItemWithState(m map[string]any, callNameByID map[str
 
 		functionPayload := map[string]any{
 			"name":      name,
-			"arguments": stringifyToolCallArguments(argsRaw),
+			"arguments": prompt.StringifyToolCallArguments(argsRaw),
 		}
 		call := map[string]any{
 			"type":     "function",
@@ -211,26 +211,3 @@ func normalizeResponsesFallbackPart(m map[string]any) string {
 	}
 	return strings.TrimSpace(fmt.Sprintf("%v", m))
 }
-
-func stringifyToolCallArguments(v any) string {
-	switch x := v.(type) {
-	case nil:
-		return "{}"
-	case string:
-		s := strings.TrimSpace(x)
-		if s == "" {
-			return "{}"
-		}
-		s = normalizeToolArgumentString(s)
-		if s == "" {
-			return "{}"
-		}
-		return s
-	default:
-		b, err := json.Marshal(x)
-		if err != nil || len(b) == 0 {
-			return "{}"
-		}
-		return string(b)
-	}
-}

internal/adapter/openai/tool_history_sanitize.go

@@ -4,7 +4,6 @@ import (
 	"regexp"
 )
 
-var leakedToolHistoryPattern = regexp.MustCompile(`(?is)\[TOOL_CALL_HISTORY\][\s\S]*?\[/TOOL_CALL_HISTORY\]|\[TOOL_RESULT_HISTORY\][\s\S]*?\[/TOOL_RESULT_HISTORY\]`)
 var emptyJSONFencePattern = regexp.MustCompile("(?is)```json\\s*```")
 var leakedToolCallArrayPattern = regexp.MustCompile(`(?is)\[\{\s*"function"\s*:\s*\{[\s\S]*?\}\s*,\s*"id"\s*:\s*"call[^"]*"\s*,\s*"type"\s*:\s*"function"\s*}\]`)
 var leakedToolResultBlobPattern = regexp.MustCompile(`(?is)<\s*\|\s*tool\s*\|\s*>\s*\{[\s\S]*?"tool_call_id"\s*:\s*"call[^"]*"\s*}`)
@@ -22,8 +21,7 @@ func sanitizeLeakedToolHistory(text string) string {
 	if text == "" {
 		return text
 	}
-	out := leakedToolHistoryPattern.ReplaceAllString(text, "")
-	out = emptyJSONFencePattern.ReplaceAllString(out, "")
+	out := emptyJSONFencePattern.ReplaceAllString(text, "")
 	out = leakedToolCallArrayPattern.ReplaceAllString(out, "")
 	out = leakedToolResultBlobPattern.ReplaceAllString(out, "")
 	out = leakedMetaMarkerPattern.ReplaceAllString(out, "")

internal/adapter/openai/tool_history_sanitize_test.go

@@ -2,47 +2,6 @@ package openai
 
 import "testing"
 
-func TestSanitizeLeakedToolHistoryRemovesMarkerBlocks(t *testing.T) {
-	raw := "前缀\n[TOOL_CALL_HISTORY]\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_CALL_HISTORY]\n后缀"
-	got := sanitizeLeakedToolHistory(raw)
-	if got != "前缀\n\n后缀" {
-		t.Fatalf("unexpected sanitized content: %q", got)
-	}
-}
-
-func TestSanitizeLeakedToolHistoryPreservesChunkWhitespace(t *testing.T) {
-	cases := []struct {
-		name string
-		raw  string
-		want string
-	}{
-		{
-			name: "trailing space kept",
-			raw:  "Hello ",
-			want: "Hello ",
-		},
-		{
-			name: "leading newline kept",
-			raw:  "\nworld",
-			want: "\nworld",
-		},
-		{
-			name: "surrounding whitespace around marker is preserved",
-			raw:  "A \n[TOOL_RESULT_HISTORY]\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_RESULT_HISTORY]\n B",
-			want: "A \n\n B",
-		},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			got := sanitizeLeakedToolHistory(tc.raw)
-			if got != tc.want {
-				t.Fatalf("unexpected sanitize result, want %q got %q", tc.want, got)
-			}
-		})
-	}
-}
-
 func TestSanitizeLeakedToolHistoryRemovesEmptyJSONFence(t *testing.T) {
 	raw := "before\n```json\n```\nafter"
 	got := sanitizeLeakedToolHistory(raw)
@@ -51,32 +10,6 @@ func TestSanitizeLeakedToolHistoryRemovesEmptyJSONFence(t *testing.T) {
 	}
 }
 
-func TestFlushToolSieveDropsToolHistoryLeak(t *testing.T) {
-	var state toolStreamSieveState
-	chunk := "[TOOL_CALL_HISTORY]\nstatus: already_called\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_CALL_HISTORY]"
-	evts := processToolSieveChunk(&state, chunk, []string{"exec"})
-	if len(evts) != 0 {
-		t.Fatalf("expected no immediate output before history block is complete, got %+v", evts)
-	}
-	flushed := flushToolSieve(&state, []string{"exec"})
-	if len(flushed) != 0 {
-		t.Fatalf("expected history block to be swallowed, got %+v", flushed)
-	}
-}
-
-func TestFlushToolSieveDropsToolResultHistoryLeak(t *testing.T) {
-	var state toolStreamSieveState
-	chunk := "[TOOL_RESULT_HISTORY]\nstatus: already_called\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_RESULT_HISTORY]"
-	evts := processToolSieveChunk(&state, chunk, []string{"exec"})
-	if len(evts) != 0 {
-		t.Fatalf("expected no immediate output before result history block is complete, got %+v", evts)
-	}
-	flushed := flushToolSieve(&state, []string{"exec"})
-	if len(flushed) != 0 {
-		t.Fatalf("expected result history block to be swallowed, got %+v", flushed)
-	}
-}
-
 func TestSanitizeLeakedToolHistoryRemovesLeakedWireToolCallAndResult(t *testing.T) {
 	raw := "开始\n[{\"function\":{\"arguments\":\"{\\\"command\\\":\\\"java -version\\\"}\",\"name\":\"exec\"},\"id\":\"callb9a321\",\"type\":\"function\"}]< | Tool | >{\"content\":\"openjdk version 21\",\"tool_call_id\":\"callb9a321\"}\n结束"
 	got := sanitizeLeakedToolHistory(raw)
@@ -100,31 +33,3 @@ func TestSanitizeLeakedToolHistoryRemovesAgentXMLLeaks(t *testing.T) {
 		t.Fatalf("unexpected sanitize result for agent XML leak: %q", got)
 	}
 }
-
-func TestProcessToolSieveChunkSplitsResultHistoryBoundary(t *testing.T) {
-	var state toolStreamSieveState
-	parts := []string{
-		"Hello ",
-		"[TOOL_RESULT_HISTORY]\nstatus: already_called\n",
-		"function.name: exec\nfunction.arguments: {}\n[/TOOL_RESULT_HISTORY]",
-		"world",
-	}
-	var events []toolStreamEvent
-	for _, p := range parts {
-		events = append(events, processToolSieveChunk(&state, p, []string{"exec"})...)
-	}
-	events = append(events, flushToolSieve(&state, []string{"exec"})...)
-
-	var text string
-	for _, evt := range events {
-		if evt.Content != "" {
-			text += evt.Content
-		}
-		if len(evt.ToolCalls) > 0 {
-			t.Fatalf("did not expect parsed tool calls from history leak: %+v", evt.ToolCalls)
-		}
-	}
-	if text != "Hello world" {
-		t.Fatalf("expected clean text output preserving boundary spaces, got %q", text)
-	}
-}

internal/adapter/openai/tool_sieve_core.go

@@ -183,7 +183,7 @@ func findToolSegmentStart(s string) int {
 		return -1
 	}
 	lower := strings.ToLower(s)
-	keywords := []string{"tool_calls", "\"function\"", "function.name:", "[tool_call_history]", "[tool_result_history]"}
+	keywords := []string{"tool_calls", "\"function\"", "function.name:"}
 	bestKeyIdx := -1
 	for _, kw := range keywords {
 		idx := strings.Index(lower, kw)
@@ -240,7 +240,7 @@ func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix
 
 	lower := strings.ToLower(captured)
 	keyIdx := -1
-	keywords := []string{"tool_calls", "\"function\"", "function.name:", "[tool_call_history]", "[tool_result_history]"}
+	keywords := []string{"tool_calls", "\"function\"", "function.name:"}
 	for _, kw := range keywords {
 		idx := strings.Index(lower, kw)
 		if idx >= 0 && (keyIdx < 0 || idx < keyIdx) {
@@ -253,9 +253,6 @@ func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix
 	}
 	start := strings.LastIndex(captured[:keyIdx], "{")
 	if start < 0 {
-		if blockStart, blockEnd, ok := extractToolHistoryBlock(captured, keyIdx); ok {
-			return captured[:blockStart], nil, captured[blockEnd:], true
-		}
 		start = keyIdx
 	}
 	obj, end, ok := extractJSONObjectFrom(captured, start)

internal/adapter/openai/tool_sieve_jsonscan.go

@@ -44,31 +44,6 @@ func extractJSONObjectFrom(text string, start int) (string, int, bool) {
 	return "", 0, false
 }
 
-func extractToolHistoryBlock(captured string, keyIdx int) (start int, end int, ok bool) {
-	if keyIdx < 0 || keyIdx >= len(captured) {
-		return 0, 0, false
-	}
-	rest := strings.ToLower(captured[keyIdx:])
-	switch {
-	case strings.HasPrefix(rest, "[tool_call_history]"):
-		closeTag := "[/tool_call_history]"
-		closeIdx := strings.Index(rest, closeTag)
-		if closeIdx < 0 {
-			return 0, 0, false
-		}
-		return keyIdx, keyIdx + closeIdx + len(closeTag), true
-	case strings.HasPrefix(rest, "[tool_result_history]"):
-		closeTag := "[/tool_result_history]"
-		closeIdx := strings.Index(rest, closeTag)
-		if closeIdx < 0 {
-			return 0, 0, false
-		}
-		return keyIdx, keyIdx + closeIdx + len(closeTag), true
-	default:
-		return 0, 0, false
-	}
-}
-
 func trimWrappingJSONFence(prefix, suffix string) (string, string) {
 	trimmedPrefix := strings.TrimRight(prefix, " \t\r\n")
 	fenceIdx := strings.LastIndex(trimmedPrefix, "```")

internal/js/helpers/stream-tool-sieve/jsonscan.js

@@ -140,30 +140,6 @@ function extractJSONObjectFrom(text, start) {
   return { ok: false, end: 0 };
 }
 
-function extractToolHistoryBlock(captured, keyIdx) {
-  if (typeof captured !== 'string' || keyIdx < 0 || keyIdx >= captured.length) {
-    return { ok: false, start: 0, end: 0 };
-  }
-  const rest = captured.slice(keyIdx).toLowerCase();
-  if (rest.startsWith('[tool_call_history]')) {
-    const closeTag = '[/tool_call_history]';
-    const closeIdx = rest.indexOf(closeTag);
-    if (closeIdx < 0) {
-      return { ok: false, start: 0, end: 0 };
-    }
-    return { ok: true, start: keyIdx, end: keyIdx + closeIdx + closeTag.length };
-  }
-  if (rest.startsWith('[tool_result_history]')) {
-    const closeTag = '[/tool_result_history]';
-    const closeIdx = rest.indexOf(closeTag);
-    if (closeIdx < 0) {
-      return { ok: false, start: 0, end: 0 };
-    }
-    return { ok: true, start: keyIdx, end: keyIdx + closeIdx + closeTag.length };
-  }
-  return { ok: false, start: 0, end: 0 };
-}
-
 function trimWrappingJSONFence(prefix, suffix) {
   const rightTrimmedPrefix = (prefix || '').replace(/[ \t\r\n]+$/g, '');
   const fenceIdx = rightTrimmedPrefix.lastIndexOf('```');
@@ -192,6 +168,5 @@ module.exports = {
   parseJSONStringLiteral,
   skipSpaces,
   extractJSONObjectFrom,
-  extractToolHistoryBlock,
   trimWrappingJSONFence,
 };

internal/js/helpers/stream-tool-sieve/sieve.js

@@ -5,7 +5,7 @@ const {
   insideCodeFenceWithState,
 } = require('./state');
 const { parseStandaloneToolCallsDetailed } = require('./parse');
-const { extractJSONObjectFrom, extractToolHistoryBlock, trimWrappingJSONFence } = require('./jsonscan');
+const { extractJSONObjectFrom, trimWrappingJSONFence } = require('./jsonscan');
 const {
   TOOL_SEGMENT_KEYWORDS,
   XML_TOOL_SEGMENT_TAGS,
@@ -233,17 +233,6 @@ function consumeToolCapture(state, toolNames) {
   }
   const start = captured.slice(0, keyIdx).lastIndexOf('{');
   const actualStart = start >= 0 ? start : keyIdx;
-  if (start < 0) {
-    const history = extractToolHistoryBlock(captured, keyIdx);
-    if (history.ok) {
-      return {
-        ready: true,
-        prefix: captured.slice(0, history.start),
-        calls: [],
-        suffix: captured.slice(history.end),
-      };
-    }
-  }
   const obj = extractJSONObjectFrom(captured, actualStart);
   if (!obj.ok) {
     return { ready: false, prefix: '', calls: [], suffix: '' };

internal/js/helpers/stream-tool-sieve/tool-keywords.js

@@ -4,8 +4,6 @@ const TOOL_SEGMENT_KEYWORDS = [
   'tool_calls',
   '"function"',
   'function.name:',
-  '[tool_call_history]',
-  '[tool_result_history]',
 ];
 
 const XML_TOOL_SEGMENT_TAGS = [

internal/prompt/tool_calls.go

@@ -0,0 +1,124 @@
+package prompt
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// FormatToolCallsForPrompt renders a tool_calls slice into the canonical
+// prompt-visible history block used across adapters.
+func FormatToolCallsForPrompt(raw any) string {
+	calls, ok := raw.([]any)
+	if !ok || len(calls) == 0 {
+		return ""
+	}
+
+	blocks := make([]string, 0, len(calls))
+	for _, item := range calls {
+		call, ok := item.(map[string]any)
+		if !ok {
+			continue
+		}
+		block := formatToolCallForPrompt(call)
+		if block != "" {
+			blocks = append(blocks, block)
+		}
+	}
+	if len(blocks) == 0 {
+		return ""
+	}
+	return "<tool_calls>\n" + strings.Join(blocks, "\n") + "\n</tool_calls>"
+}
+
+// StringifyToolCallArguments normalizes tool arguments into a compact string
+// while preserving raw concatenated payloads when they already look like model
+// output rather than a single JSON object.
+func StringifyToolCallArguments(v any) string {
+	switch x := v.(type) {
+	case nil:
+		return "{}"
+	case string:
+		s := strings.TrimSpace(x)
+		if s == "" {
+			return "{}"
+		}
+		s = normalizeToolArgumentString(s)
+		if s == "" {
+			return "{}"
+		}
+		return s
+	default:
+		b, err := json.Marshal(x)
+		if err != nil || len(b) == 0 {
+			return "{}"
+		}
+		return string(b)
+	}
+}
+
+func formatToolCallForPrompt(call map[string]any) string {
+	if call == nil {
+		return ""
+	}
+
+	name := strings.TrimSpace(asString(call["name"]))
+	fn, _ := call["function"].(map[string]any)
+	if name == "" && fn != nil {
+		name = strings.TrimSpace(asString(fn["name"]))
+	}
+	if name == "" {
+		return ""
+	}
+
+	argsRaw := call["arguments"]
+	if argsRaw == nil {
+		argsRaw = call["input"]
+	}
+	if argsRaw == nil && fn != nil {
+		argsRaw = fn["arguments"]
+		if argsRaw == nil {
+			argsRaw = fn["input"]
+		}
+	}
+
+	return "  <tool_call>\n" +
+		"    <tool_name>" + name + "</tool_name>\n" +
+		"    <parameters>" + StringifyToolCallArguments(argsRaw) + "</parameters>\n" +
+		"  </tool_call>"
+}
+
+func normalizeToolArgumentString(raw string) string {
+	trimmed := strings.TrimSpace(raw)
+	if trimmed == "" {
+		return ""
+	}
+	if looksLikeConcatenatedJSON(trimmed) {
+		// Keep the original payload to avoid silently rewriting model output.
+		return raw
+	}
+	return trimmed
+}
+
+func looksLikeConcatenatedJSON(raw string) bool {
+	trimmed := strings.TrimSpace(raw)
+	if trimmed == "" {
+		return false
+	}
+	if strings.Contains(trimmed, "}{") || strings.Contains(trimmed, "][") {
+		return true
+	}
+	dec := json.NewDecoder(strings.NewReader(trimmed))
+	var first any
+	if err := dec.Decode(&first); err != nil {
+		return false
+	}
+	var second any
+	return dec.Decode(&second) == nil
+}
+
+func asString(v any) string {
+	if s, ok := v.(string); ok {
+		return s
+	}
+	return ""
+}

internal/prompt/tool_calls_test.go

@@ -0,0 +1,28 @@
+package prompt
+
+import "testing"
+
+func TestStringifyToolCallArgumentsPreservesConcatenatedJSON(t *testing.T) {
+	got := StringifyToolCallArguments(`{}{"query":"测试工具调用"}`)
+	if got != `{}{"query":"测试工具调用"}` {
+		t.Fatalf("expected raw concatenated JSON to be preserved, got %q", got)
+	}
+}
+
+func TestFormatToolCallsForPromptXML(t *testing.T) {
+	got := FormatToolCallsForPrompt([]any{
+		map[string]any{
+			"id": "call_1",
+			"function": map[string]any{
+				"name":      "search_web",
+				"arguments": map[string]any{"query": "latest"},
+			},
+		},
+	})
+	if got == "" {
+		t.Fatal("expected non-empty formatted tool calls")
+	}
+	if got != "<tool_calls>\n  <tool_call>\n    <tool_name>search_web</tool_name>\n    <parameters>{\"query\":\"latest\"}</parameters>\n  </tool_call>\n</tool_calls>" {
+		t.Fatalf("unexpected formatted tool call XML: %q", got)
+	}
+}

internal/util/toolcalls_candidates.go

@@ -64,7 +64,7 @@ func extractToolCallObjects(text string) []string {
 	lower := strings.ToLower(text)
 	out := []string{}
 	offset := 0
-	keywords := []string{"tool_calls", "\"function\"", "function.name:", "[tool_call_history]"}
+	keywords := []string{"tool_calls", "\"function\"", "function.name:"}
 	for {
 		bestIdx := -1
 		matchedKeyword := ""

internal/util/toolcalls_textkv_test.go

@@ -6,14 +6,12 @@ import (
 
 func TestParseTextKVToolCalls_Basic(t *testing.T) {
 	text := `
-[TOOL_CALL_HISTORY]
 status: already_called
 origin: assistant
 not_user_input: true
 tool_call_id: call_3fcd15235eb94f7eae3a8de5a9cfa36b
 function.name: execute_command
 function.arguments: {"command":"cd scripts && python check_syntax.py example.py","cwd":null,"timeout":30}
-[/TOOL_CALL_HISTORY]
 
 Some other text thinking...
 `

tests/node/stream-tool-sieve.test.js

@@ -98,10 +98,8 @@ test('parseToolCalls ignores tool_call payloads that exist only inside fenced co
 
 test('parseToolCalls parses text-kv fallback payload', () => {
   const text = [
-    '[TOOL_CALL_HISTORY]',
     'function.name: execute_command',
     'function.arguments: {"command":"cd scripts && python check_syntax.py example.py","cwd":null,"timeout":30}',
-    '[/TOOL_CALL_HISTORY]',
     'Some other text thinking...',
   ].join('\n');
   const calls = parseToolCalls(text, ['execute_command']);
@@ -254,56 +252,6 @@ test('sieve keeps plain text intact in tool mode when no tool call appears', ()
   assert.equal(leakedText, '你好，这是普通文本回复。请继续。');
 });
 
-test('sieve swallows leaked TOOL_CALL_HISTORY marker blocks', () => {
-  const events = runSieve(
-    [
-      '前置文本。',
-      '[TOOL_CALL_HISTORY]\nstatus: already_called\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_CALL_HISTORY]',
-      '后置文本。',
-    ],
-    ['exec'],
-  );
-  const leakedText = collectText(events);
-  const hasToolCall = events.some((evt) => evt.type === 'tool_calls');
-  assert.equal(hasToolCall, false);
-  assert.equal(leakedText.includes('前置文本。'), true);
-  assert.equal(leakedText.includes('后置文本。'), true);
-  assert.equal(leakedText.includes('[TOOL_CALL_HISTORY]'), false);
-});
-
-test('sieve swallows leaked TOOL_RESULT_HISTORY marker blocks', () => {
-  const events = runSieve(
-    [
-      '前置文本。',
-      '[TOOL_RESULT_HISTORY]\nstatus: already_called\nfunction.name: exec\nfunction.arguments: {}\n[/TOOL_RESULT_HISTORY]',
-      '后置文本。',
-    ],
-    ['exec'],
-  );
-  const leakedText = collectText(events);
-  const hasToolCall = events.some((evt) => evt.type === 'tool_calls');
-  assert.equal(hasToolCall, false);
-  assert.equal(leakedText.includes('前置文本。'), true);
-  assert.equal(leakedText.includes('后置文本。'), true);
-  assert.equal(leakedText.includes('[TOOL_RESULT_HISTORY]'), false);
-});
-
-test('sieve preserves text spacing when TOOL_RESULT_HISTORY spans chunks', () => {
-  const events = runSieve(
-    [
-      'Hello ',
-      '[TOOL_RESULT_HISTORY]\nstatus: already_called\n',
-      'function.name: exec\nfunction.arguments: {}\n[/TOOL_RESULT_HISTORY]',
-      'world',
-    ],
-    ['exec'],
-  );
-  const leakedText = collectText(events);
-  const hasToolCall = events.some((evt) => evt.type === 'tool_calls' && evt.calls?.length > 0);
-  assert.equal(hasToolCall, false);
-  assert.equal(leakedText, 'Hello world');
-});
-
 test('sieve emits unknown tool payload (no args) as executable tool call', () => {
   const events = runSieve(
     ['{"tool_calls":[{"name":"not_in_schema"}]}', '后置正文G。'],