diff --git a/app/api/routes/api.py b/app/api/routes/api.py
index 0bccf5d..efe2a21 100644
--- a/app/api/routes/api.py
+++ b/app/api/routes/api.py
@@ -7,6 +7,8 @@ from app.schemas.dtos import (
     TokenResponse,
     AccountBalanceDTO,
     LedgerEntryDTO,
+    CreateMarketMetadataRequest,
+    ResolveMarketRequest,
     MarketDTO,
     CreateOrderRequest,
     OrderDTO
@@ -24,6 +26,39 @@ async def login_with_wallet(req: UserAuthRequest, session: AsyncSession = Depend
     return TokenResponse(access_token=token, address=req.address.lower())
 
 # ================= Market Routes =================
+@api_router.post("/markets/metadata", response_model=MarketDTO)
+async def create_market_metadata(
+    req: CreateMarketMetadataRequest,
+    current_user: str = Depends(get_current_user),
+    session: AsyncSession = Depends(get_db_session)
+):
+    """保存预测市场的链下元数据 (标题, 描述, 类别, 2~255个选项)"""
+    market_service = MarketService(session)
+    market = await market_service.save_market_metadata(
+        market_address=req.market_address,
+        question_id=req.question_id,
+        title=req.title,
+        description=req.description,
+        category=req.category,
+        outcomes=req.outcomes,
+        resolution_time=req.resolution_time,
+        creator=current_user
+    )
+    return MarketDTO(
+        market_address=market.market_address,
+        question_id=market.question_id,
+        title=market.title,
+        description=market.description,
+        category=market.category,
+        tier=market.tier,
+        creator=market.creator,
+        status=market.status.value if hasattr(market.status, 'value') else str(market.status),
+        outcomes=market.outcomes,
+        winning_outcome=market.winning_outcome,
+        resolution_time=market.resolution_time,
+        created_at=market.created_at
+    )
+
 @api_router.get("/markets", response_model=List[MarketDTO])
 async def get_markets(
     category: Optional[str] = None,
diff --git a/app/domains/trading/service.py b/app/domains/trading/service.py
index 9bbc2af..687687c 100644
--- a/app/domains/trading/service.py
+++ b/app/domains/trading/service.py
@@ -12,6 +12,38 @@ class MarketService:
     def __init__(self, session: AsyncSession):
         self.session = session
 
+    async def save_market_metadata(
+        self,
+        market_address: str,
+        question_id: str,
+        title: str,
+        description: Optional[str],
+        category: str,
+        outcomes: List[str],
+        resolution_time,
+        creator: str
+    ) -> MarketModel:
+        market = MarketModel(
+            market_address=market_address.lower(),
+            question_id=question_id.lower(),
+            title=title,
+            description=description,
+            category=category or "Others",
+            tier=1,
+            creator=creator.lower(),
+            curve_address="0xF0E189974c413506098AFB6Bc6Bf4C6715fBf7B1",
+            collateral_address="0xe776e957953EA69b7Eaa9d7d4098aBC076bDD5E7",
+            fee_rate=Decimal("0.006"),
+            resolution_time=resolution_time,
+            outcomes=outcomes,
+            num_outcomes=len(outcomes),
+            status=MarketStatus.ACTIVE,
+            created_at_block=0
+        )
+        self.session.add(market)
+        await self.session.flush()
+        return market
+
     async def list_markets(self, category: Optional[str] = None, status: Optional[str] = None) -> List[MarketModel]:
         stmt = select(MarketModel)
         if category:
diff --git a/app/schemas/dtos.py b/app/schemas/dtos.py
index 525035d..00a19c5 100644
--- a/app/schemas/dtos.py
+++ b/app/schemas/dtos.py
@@ -28,13 +28,15 @@ class LedgerEntryDTO(BaseModel):
     related_market: Optional[str] = None
     created_at: datetime
 
-class CreateMarketRequest(BaseModel):
+class CreateMarketMetadataRequest(BaseModel):
+    market_address: str
+    question_id: str
     title: str
     description: Optional[str] = None
-    category: str = "Crypto"
-    tier: int = 1
+    category: str = "Others" # 默认 Others，支持用户自定义
+    outcomes: List[str] = Field(..., min_length=2, max_length=255) # 支持最多 255 个选项
     resolution_time: datetime
-    outcomes: List[str] = Field(..., min_length=2, max_length=8)
+    creator: str
 
 class MarketDTO(BaseModel):
     market_address: str
@@ -50,10 +52,15 @@ class MarketDTO(BaseModel):
     resolution_time: datetime
     created_at: datetime
 
+class ResolveMarketRequest(BaseModel):
+    market_address: str
+    question_id: str
+    winning_outcome_index: int = Field(..., ge=0, le=255)
+
 class CreateOrderRequest(BaseModel):
     market_address: str
     vault_address: Optional[str] = None
-    outcome_index: int = Field(..., ge=0, le=7)
+    outcome_index: int = Field(..., ge=0, le=255)
     side: str = Field(..., pattern="^(BUY|SELL)$")
     amount: Decimal = Field(..., gt=0)
     price: Optional[Decimal] = None