feat: 补全模型能力选项(11种) + 按能力指定默认模型 + Auto自动模式

backend/python/app/api/chat.py

@@ -27,6 +27,7 @@ from ..models import (
 )
 from ..auth import get_current_user
 from ..middleware.log_service import LogService
+from ..capability_registry import resolve_auto_model
 
 router = APIRouter()
 
@@ -981,9 +982,14 @@ async def send_message(
     ai_model = None
     skills = []  # 初始化避免UnboundLocalError
     agents = []  # 初始化避免UnboundLocalError
-    if model_id:
+    # 解析模型：支持 Auto 模式（model_id='auto' 或未指定时，按能力自动匹配平台默认模型）
+    if model_id and model_id != "auto":
         ai_model = db.query(AIModel).filter(AIModel.id == model_id).first()
+    if not ai_model:
+        # Auto / 未指定 → 使用平台默认对话模型（文本能力默认）
+        ai_model = resolve_auto_model("text", db)
 
+    if ai_model:
         # ====== 图像/视频生成模型分支 ======
         caps = [c.lower() for c in (ai_model.capabilities or [])] if ai_model else []
         if ai_model and ("image" in caps or "video" in caps):
@@ -1137,7 +1143,7 @@ async def send_message(
         else:
             ai_content = "请选择一个已配置的AI模型进行对话。"
     else:
-        ai_content = "请先在聊天设置中选择一个AI模型。"
+        ai_content = "请先在后台管理-大模型库配置默认对话模型（或聊天中选择模型），Auto 模式下将自动使用平台默认模型。"
 
     ai_token_count = len(ai_content) // 2
     ai_msg = Message(
@@ -1146,7 +1152,7 @@ async def send_message(
         role="assistant",
         content=ai_content,
         token_used=ai_token_count,
-        model_id=req.model_id or conv.model_id,
+        model_id=ai_model.id if ai_model else (req.model_id or conv.model_id),
         skill_ids=req.skill_ids if req.skill_ids else None,
         agent_ids=req.agent_ids if req.agent_ids else None,
         knowledge_ids=req.knowledge_base_ids if req.knowledge_base_ids else None,
@@ -1168,8 +1174,8 @@ async def send_message(
     token_usage = TokenUsageLog(
         id=gen_uuid(),
         user_id=current_user.id,
-        model_id=req.model_id or conv.model_id,
-        model_name=ai_model.name if model_id and ai_model else None,
+        model_id=ai_model.id if ai_model else (req.model_id or conv.model_id),
+        model_name=ai_model.name if ai_model else None,
         conversation_id=conv_id,
         prompt_tokens=prompt_tokens or len(req.content) // 2,
         completion_tokens=completion_tokens or ai_token_count,
@@ -1454,3 +1460,4 @@ def get_models(db: Session = Depends(get_db)):
         })
     result.sort(key=lambda x: (0 if x["is_default"] else 1, x["name"]))
     return {"code": 0, "data": result, "message": "ok"}
+

backend/python/app/capability_registry.py

@@ -0,0 +1,97 @@
+"""
+能力(capability)注册中心
+
+集中定义平台支持的全部模型能力，以及"每个能力对应的默认模型"的读写与解析。
+- CAPABILITY_TYPES: 全部能力（id / 中文标签 / 测试类型 / 描述）
+- get_capability_defaults / set_capability_default: 读写 site_settings 中的 model_capability_defaults
+- resolve_auto_model: 根据能力解析平台默认模型（供聊天 / 技能 / 应用 / IM Bot 自动匹配）
+"""
+from typing import Optional
+from sqlalchemy.orm import Session
+from .models import AIModel, SiteSetting
+import json
+
+
+# ============================================================
+# 平台支持的全部能力类型
+# test_type 用于模型连接测试时选择对应的 API 路径
+# ============================================================
+CAPABILITY_TYPES = [
+    {"id": "text",       "label": "文本对话", "test_type": "text",       "desc": "文本生成与多轮对话"},
+    {"id": "thinking",   "label": "推理思考", "test_type": "text",       "desc": "深度推理 / 思维链"},
+    {"id": "vision",     "label": "视觉理解", "test_type": "vision",     "desc": "图片 / 多模态理解"},
+    {"id": "tool",       "label": "工具调用", "test_type": "text",       "desc": "Function Calling 函数调用"},
+    {"id": "image",      "label": "图像生成", "test_type": "image",      "desc": "文生图 / 图像生成"},
+    {"id": "audio",      "label": "语音合成", "test_type": "audio",      "desc": "TTS 文字转语音"},
+    {"id": "asr",        "label": "语音识别", "test_type": "asr",        "desc": "ASR 语音转文字"},
+    {"id": "ocr",        "label": "OCR识别",  "test_type": "ocr",        "desc": "图片文字识别提取"},
+    {"id": "embedding",  "label": "嵌入向量", "test_type": "embedding",  "desc": "文本向量化 / 嵌入"},
+    {"id": "rerank",     "label": "重排序",   "test_type": "rerank",     "desc": "语义重排 / Rerank"},
+    {"id": "video",      "label": "视频生成", "test_type": "video",      "desc": "文生视频 / 视频生成"},
+]
+
+# 文本类能力（对话 / 视觉 / 推理 / 工具 / OCR）在缺少专属默认模型时，回退到全局默认模型
+TEXT_FAMILY = {"text", "thinking", "vision", "tool", "ocr"}
+
+# 仅用于前端展示的固定配色
+CAPABILITY_COLORS = {
+    "text": "#5B5FED", "thinking": "#8B5CF6", "vision": "#219B5E", "tool": "#3B82F6",
+    "image": "#D9383A", "audio": "#E8922C", "asr": "#0EA5E9", "ocr": "#F59E0B",
+    "embedding": "#10B981", "rerank": "#EC4899", "video": "#EF4444",
+}
+
+SETTING_KEY = "model_capability_defaults"
+
+
+def get_capability_defaults(db: Session) -> dict:
+    """读取 {capability: model_id} 映射"""
+    row = db.query(SiteSetting).filter(SiteSetting.key == SETTING_KEY).first()
+    if not row or not row.value:
+        return {}
+    try:
+        data = json.loads(row.value)
+        return data if isinstance(data, dict) else {}
+    except Exception:
+        return {}
+
+
+def set_capability_default(db: Session, capability: str, model_id: Optional[str]) -> dict:
+    """设置某个能力的默认模型（model_id 为空则清除）"""
+    data = get_capability_defaults(db)
+    if model_id:
+        data[capability] = model_id
+    else:
+        data.pop(capability, None)
+    row = db.query(SiteSetting).filter(SiteSetting.key == SETTING_KEY).first()
+    if not row:
+        from uuid import uuid4
+        row = SiteSetting(id=str(uuid4()), key=SETTING_KEY, value="{}")
+        db.add(row)
+    row.value = json.dumps(data, ensure_ascii=False)
+    db.commit()
+    return data
+
+
+def resolve_auto_model(capability: str, db: Session) -> Optional[AIModel]:
+    """
+    根据能力解析平台默认模型：
+    1. 优先使用后台"按能力默认模型"中配置的值
+    2. 文本类能力若未单独配置，回退到全局默认模型(is_default)
+    3. 其余能力(embedding/rerank/asr 等)若未配置则返回 None
+    """
+    data = get_capability_defaults(db)
+    mid = data.get(capability)
+    if mid:
+        m = db.query(AIModel).filter(
+            AIModel.id == mid, AIModel.is_enabled == True
+        ).first()
+        if m:
+            return m
+    # 文本类能力回退到全局默认模型
+    if capability in TEXT_FAMILY:
+        m = db.query(AIModel).filter(
+            AIModel.is_default == True, AIModel.is_enabled == True
+        ).first()
+        if m:
+            return m
+    return None