fix(normalizer): 移除 Claude system 中的 billing header

src/core/api_format/conversion/normalizers/claude.py

@@ -66,6 +66,7 @@ from src.core.logger import logger
 
 class ClaudeNormalizer(FormatNormalizer):
     FORMAT_ID = "claude:chat"
+    _ANTHROPIC_BILLING_HEADER_PREFIX = "x-anthropic-billing-header:"
     capabilities = FormatCapabilities(
         supports_stream=True,
         supports_error_conversion=True,
@@ -1128,7 +1129,12 @@ class ClaudeNormalizer(FormatNormalizer):
         if system_value is None:
             return None, dropped, None
         if isinstance(system_value, str):
-            return (system_value or None), dropped, None
+            sanitized_text, removed_header_count = self._strip_anthropic_billing_headers(
+                system_value
+            )
+            if removed_header_count:
+                dropped["claude_system_billing_header_removed"] = removed_header_count
+            return sanitized_text, dropped, None
 
         if isinstance(system_value, list):
             texts: list[str] = []
@@ -1143,14 +1149,26 @@ class ClaudeNormalizer(FormatNormalizer):
                 if item.get("type") == "text":
                     text = item.get("text")
                     if text:
-                        texts.append(str(text))
+                        normalized_text, removed_header_count = (
+                            self._strip_anthropic_billing_headers(text)
+                        )
+                        if removed_header_count:
+                            dropped["claude_system_billing_header_removed"] = (
+                                dropped.get("claude_system_billing_header_removed", 0)
+                                + removed_header_count
+                            )
+                        if not normalized_text:
+                            continue
+                        texts.append(normalized_text)
                         seg_extra: dict[str, Any] = {}
                         cc = item.get("cache_control")
                         if isinstance(cc, dict):
                             seg_extra["cache_control"] = cc
                             has_cache_control = True
                         segments.append(
-                            InstructionSegment(role=Role.SYSTEM, text=str(text), extra=seg_extra)
+                            InstructionSegment(
+                                role=Role.SYSTEM, text=normalized_text, extra=seg_extra
+                            )
                         )
                 else:
                     dropped_key = f"claude_system_item:{item.get('type')}"
@@ -1165,6 +1183,28 @@ class ClaudeNormalizer(FormatNormalizer):
         dropped["claude_system_unsupported"] = dropped.get("claude_system_unsupported", 0) + 1
         return None, dropped, None
 
+    def _strip_anthropic_billing_headers(self, text: Any) -> tuple[str | None, int]:
+        normalized_text = str(text)
+        stripped_leading = normalized_text.lstrip()
+        if not stripped_leading.lower().startswith(self._ANTHROPIC_BILLING_HEADER_PREFIX):
+            return normalized_text, 0
+
+        lines = stripped_leading.splitlines(keepends=True)
+        idx = 0
+        removed_header_count = 0
+        while idx < len(lines) and lines[idx].strip().lower().startswith(
+            self._ANTHROPIC_BILLING_HEADER_PREFIX
+        ):
+            removed_header_count += 1
+            idx += 1
+        while idx < len(lines) and not lines[idx].strip():
+            idx += 1
+
+        sanitized_text = "".join(lines[idx:])
+        if not sanitized_text.strip():
+            return None, removed_header_count
+        return sanitized_text, removed_header_count
+
     def _join_instructions(self, instructions: list[InstructionSegment]) -> str | None:
         parts = [seg.text for seg in instructions if seg.text]
         joined = "\n\n".join(parts)

tests/core/api_format/conversion/test_claude_normalizer.py

@@ -369,8 +369,8 @@ def test_claude_request_metadata_preserved() -> None:
     assert out["metadata"]["user_id"] == "user_abc123_session_xyz456"
 
 
-def test_claude_system_array_format() -> None:
+def test_claude_system_array_format_drops_billing_header() -> None:
-    """测试 Claude CLI 风格的 system 数组格式"""
+    """Claude system 数组中的 Anthropic billing header 不应进入内部 instructions。"""
     n = ClaudeNormalizer()
 
     req = {
@@ -386,12 +386,51 @@ def test_claude_system_array_format() -> None:
 
     internal = n.request_to_internal(req)
 
-    # system 数组中的多个 text 应该用 \n\n 连接
+    # billing header 应被移除，其余 system 文本仍按顺序保留
     assert internal.system is not None
-    assert "x-anthropic-billing-header" in internal.system
+    assert "x-anthropic-billing-header" not in internal.system
     assert "You are Claude Code" in internal.system
     assert "Extract file paths" in internal.system
     assert "\n\n" in internal.system
+    assert internal.extra["raw"]["dropped_blocks"]["claude_system_billing_header_removed"] == 1
+
+
+def test_claude_system_string_strips_billing_header_and_keeps_following_prompt() -> None:
+    n = ClaudeNormalizer()
+
+    req = {
+        "model": "claude-3-opus",
+        "messages": [{"role": "user", "content": "hello"}],
+        "system": "x-anthropic-billing-header: cc_version=2.1.19\n\nYou are Claude Code.\nKeep answers terse.",
+        "max_tokens": 4096,
+    }
+
+    internal = n.request_to_internal(req)
+
+    assert internal.system == "You are Claude Code.\nKeep answers terse."
+    assert internal.extra["raw"]["dropped_blocks"]["claude_system_billing_header_removed"] == 1
+
+
+def test_claude_system_array_strips_billing_header_prefix_but_keeps_same_block_prompt() -> None:
+    n = ClaudeNormalizer()
+
+    req = {
+        "model": "claude-3-opus",
+        "messages": [{"role": "user", "content": "hello"}],
+        "system": [
+            {
+                "type": "text",
+                "text": "x-anthropic-billing-header: cc_version=2.1.19\n\nYou are Claude Code.",
+            },
+            {"type": "text", "text": "Extract file paths."},
+        ],
+        "max_tokens": 4096,
+    }
+
+    internal = n.request_to_internal(req)
+
+    assert internal.system == "You are Claude Code.\n\nExtract file paths."
+    assert internal.extra["raw"]["dropped_blocks"]["claude_system_billing_header_removed"] == 1
 
 
 def test_claude_request_reuses_raw_tool_choice_and_stabilizes_message_sequence() -> None:

tests/core/api_format/conversion/test_cli_conversion.py

@@ -71,6 +71,67 @@ def test_claude_request_to_openai_cli_places_instructions_before_input() -> None
     assert openai_cli_req["input"][0]["role"] == "user"
 
 
+def test_claude_request_to_openai_cli_drops_anthropic_billing_header() -> None:
+    reg = _make_registry_with_cli()
+
+    claude_req = {
+        "model": "claude-3-5-sonnet-latest",
+        "system": [
+            {
+                "type": "text",
+                "text": "x-anthropic-billing-header: cc_version=2.1.74.705; cc_entrypoint=claude-vscode; cch=4fb9f;",
+            },
+            {"type": "text", "text": "You are Claude Code."},
+            {"type": "text", "text": "Keep answers terse."},
+        ],
+        "messages": [{"role": "user", "content": "hi"}],
+        "max_tokens": 12,
+    }
+
+    openai_cli_req = reg.convert_request(claude_req, "claude:chat", "openai:cli")
+
+    assert openai_cli_req["instructions"] == "You are Claude Code.\n\nKeep answers terse."
+    assert "x-anthropic-billing-header" not in openai_cli_req["instructions"]
+
+
+def test_claude_request_to_openai_cli_keeps_prompt_after_billing_header_prefix() -> None:
+    reg = _make_registry_with_cli()
+
+    claude_req = {
+        "model": "claude-3-5-sonnet-latest",
+        "system": [
+            {
+                "type": "text",
+                "text": "x-anthropic-billing-header: cc_version=2.1.74.705\n\nYou are Claude Code.",
+            },
+            {"type": "text", "text": "Keep answers terse."},
+        ],
+        "messages": [{"role": "user", "content": "hi"}],
+        "max_tokens": 12,
+    }
+
+    openai_cli_req = reg.convert_request(claude_req, "claude:chat", "openai:cli")
+
+    assert openai_cli_req["instructions"] == "You are Claude Code.\n\nKeep answers terse."
+    assert "x-anthropic-billing-header" not in openai_cli_req["instructions"]
+
+
+def test_claude_request_to_openai_cli_strips_billing_header_from_string_system() -> None:
+    reg = _make_registry_with_cli()
+
+    claude_req = {
+        "model": "claude-3-5-sonnet-latest",
+        "system": "x-anthropic-billing-header: cc_version=2.1.74.705\n\nYou are Claude Code.\nKeep answers terse.",
+        "messages": [{"role": "user", "content": "hi"}],
+        "max_tokens": 12,
+    }
+
+    openai_cli_req = reg.convert_request(claude_req, "claude:chat", "openai:cli")
+
+    assert openai_cli_req["instructions"] == "You are Claude Code.\nKeep answers terse."
+    assert "x-anthropic-billing-header" not in openai_cli_req["instructions"]
+
+
 def test_claude_response_to_openai_cli() -> None:
     reg = _make_registry_with_cli()