增加注入提示词功能

routes/admin.py

@@ -135,6 +135,8 @@ def add_mapping():
         'backend': data.get('backend', 'auto'),
         'target_url': data.get('target_url', ''),
         'api_key': data.get('api_key', ''),
+        'custom_instructions': data.get('custom_instructions', ''),
+        'instructions_position': data.get('instructions_position', 'prepend'),
     }
     return _save_and_respond(s, f'映射已添加: {name}')
 
@@ -157,6 +159,8 @@ def update_mapping(name):
         'backend': data.get('backend', 'auto'),
         'target_url': data.get('target_url', ''),
         'api_key': data.get('api_key', ''),
+        'custom_instructions': data.get('custom_instructions', ''),
+        'instructions_position': data.get('instructions_position', 'prepend'),
     }
     if new_name != name:
         del mappings[name]

routes/chat.py

@@ -33,6 +33,9 @@ from routes.common import (
     build_responses_target,
     build_route_context,
     chat_error_chunk,
+    inject_instructions_anthropic,
+    inject_instructions_cc,
+    inject_instructions_responses,
     log_route_context,
     log_usage,
     sse_data_message,
@@ -108,6 +111,7 @@ def _handle_openai_backend(ctx: RouteContext, payload: dict[str, Any]):
     )
 
     payload = normalize_request(payload, ctx.upstream_model)
+    payload = inject_instructions_cc(payload, ctx.custom_instructions, ctx.instructions_position)
     _dbg(
         f'标准化完成：模型={payload.get("model")} '
         f'工具数={len(payload.get("tools", []))}'
@@ -194,6 +198,7 @@ def _handle_responses_backend(ctx: RouteContext, payload: dict[str, Any]):
     """
     responses_payload = cc_to_responses_request(payload)
     responses_payload['model'] = ctx.upstream_model
+    responses_payload = inject_instructions_responses(responses_payload, ctx.custom_instructions, ctx.instructions_position)
     _dbg(
         '已转换为 Responses 请求：字段=' + str(list(responses_payload.keys()))
         + f' 输入项数={len(responses_payload.get("input", []))}'
@@ -270,6 +275,7 @@ def _handle_anthropic_backend(ctx: RouteContext, payload: dict[str, Any]):
     """处理走 Anthropic Messages 后端的聊天补全请求。"""
     payload['model'] = ctx.upstream_model
     anthropic_payload = cc_to_messages_request(payload)
+    anthropic_payload = inject_instructions_anthropic(anthropic_payload, ctx.custom_instructions, ctx.instructions_position)
     _dbg(
         '已转换为 Messages 请求：字段=' + str(list(anthropic_payload.keys()))
         + f' 消息数={len(anthropic_payload.get("messages", []))}'

routes/common.py

@@ -22,7 +22,8 @@ class RouteContext:
     """数据面路由使用的标准请求上下文。
 
     路由层会先根据客户端模型名解析出统一上下文，后续处理函数只需要关心
-    上游模型、后端类型、目标地址、鉴权信息和流式标记，而不必重复访问配置层。
+    上游模型、后端类型、目标地址、鉴权信息、流式标记和自定义指令，
+    而不必重复访问配置层。
     """
 
     client_model: str
@@ -31,6 +32,8 @@ class RouteContext:
     target_url: str
     api_key: str
     is_stream: bool
+    custom_instructions: str
+    instructions_position: str
 
 
 def build_route_context(client_model: str, is_stream: bool) -> RouteContext:
@@ -43,6 +46,8 @@ def build_route_context(client_model: str, is_stream: bool) -> RouteContext:
         target_url=mapping['target_url'],
         api_key=mapping['api_key'],
         is_stream=is_stream,
+        custom_instructions=mapping.get('custom_instructions', ''),
+        instructions_position=mapping.get('instructions_position', 'prepend'),
     )
 
 
@@ -120,3 +125,71 @@ def chat_error_chunk(message: str, error_type: str = 'upstream_error') -> str:
 def responses_error_event(message: str) -> str:
     """构造 Responses 流式接口使用的错误事件。"""
     return sse_event_message('error', {'error': message})
+
+
+# ─── 自定义指令注入 ──────────────────────────────
+
+
+def _merge_text(custom: str, existing: str, position: str) -> str:
+    """根据 position 决定自定义指令与原有内容的拼接顺序。"""
+    if not existing:
+        return custom
+    if position == 'append':
+        return existing + '\n\n' + custom
+    return custom + '\n\n' + existing
+
+
+def inject_instructions_cc(payload: dict[str, Any], instructions: str, position: str = 'prepend') -> dict[str, Any]:
+    """向 Chat Completions 请求注入自定义指令。
+
+    position='prepend' 时放在 system 消息开头，'append' 时放在末尾。
+    """
+    if not instructions:
+        return payload
+
+    messages = payload.get('messages', [])
+    if messages and messages[0].get('role') == 'system':
+        first = messages[0]
+        original = first.get('content') or ''
+        first['content'] = _merge_text(instructions, original, position)
+    else:
+        messages.insert(0, {'role': 'system', 'content': instructions})
+        payload['messages'] = messages
+
+    logger.info('已注入自定义指令到 CC system 消息 (%d 字符, %s)', len(instructions), position)
+    return payload
+
+
+def inject_instructions_responses(payload: dict[str, Any], instructions: str, position: str = 'prepend') -> dict[str, Any]:
+    """向 Responses 请求注入自定义指令（写入 instructions 字段）。
+
+    position='prepend' 时放在 instructions 开头，'append' 时放在末尾。
+    """
+    if not instructions:
+        return payload
+
+    existing = payload.get('instructions') or ''
+    payload['instructions'] = _merge_text(instructions, existing, position)
+
+    logger.info('已注入自定义指令到 Responses instructions (%d 字符, %s)', len(instructions), position)
+    return payload
+
+
+def inject_instructions_anthropic(payload: dict[str, Any], instructions: str, position: str = 'prepend') -> dict[str, Any]:
+    """向 Anthropic Messages 请求注入自定义指令（写入 system 字段）。
+
+    position='prepend' 时放在 system 开头，'append' 时放在末尾。
+    """
+    if not instructions:
+        return payload
+
+    existing = payload.get('system') or ''
+    if isinstance(existing, list):
+        existing = '\n'.join(
+            block.get('text', '') for block in existing
+            if isinstance(block, dict) and block.get('type') == 'text'
+        )
+    payload['system'] = _merge_text(instructions, existing, position)
+
+    logger.info('已注入自定义指令到 Anthropic system (%d 字符, %s)', len(instructions), position)
+    return payload

routes/messages.py

@@ -13,6 +13,7 @@ from flask import Blueprint, request, jsonify
 
 import settings
 from config import Config
+from routes.common import inject_instructions_anthropic
 from utils.http import build_anthropic_headers, forward_request, sse_response
 
 logger = logging.getLogger(__name__)
@@ -29,11 +30,16 @@ def messages_passthrough():
 
     logger.info(f'[透传] model={model} 流式={is_stream}')
 
-    url_base = settings.get_url()
-    api_key = settings.get_key()
+    mapping = settings.resolve_model(model)
+    url_base = mapping['target_url']
+    api_key = mapping['api_key']
+    custom_instructions = mapping.get('custom_instructions', '')
+    instructions_position = mapping.get('instructions_position', 'prepend')
     headers = build_anthropic_headers(api_key)
     url = f'{url_base.rstrip("/")}/v1/messages'
 
+    payload = inject_instructions_anthropic(payload, custom_instructions, instructions_position)
+
     if not is_stream:
         resp, err = forward_request(url, headers, payload)
         if err:

routes/responses.py

@@ -22,6 +22,9 @@ from routes.common import (
     build_openai_target,
     build_responses_target,
     build_route_context,
+    inject_instructions_anthropic,
+    inject_instructions_cc,
+    inject_instructions_responses,
     log_route_context,
     log_usage,
     responses_error_event,
@@ -73,6 +76,7 @@ def _build_cc_payload(payload: dict[str, Any], ctx: RouteContext) -> dict[str, A
     """
     cc_payload = responses_to_cc(payload)
     cc_payload['model'] = ctx.upstream_model
+    cc_payload = inject_instructions_cc(cc_payload, ctx.custom_instructions, ctx.instructions_position)
     _dbg(
         '已转换为聊天补全中间表示：字段=' + str(list(cc_payload.keys()))
         + f' 消息数={len(cc_payload.get("messages", []))}'
@@ -171,6 +175,7 @@ def _handle_responses_backend(ctx: RouteContext, payload: dict[str, Any]):
     """
     payload = dict(payload)
     payload['model'] = ctx.upstream_model
+    payload = inject_instructions_responses(payload, ctx.custom_instructions, ctx.instructions_position)
     url, headers = build_responses_target(ctx)
 
     if ctx.is_stream: