feat: 实现RPC节点管理功能

- 后端功能：
  - 添加RPC节点配置管理（增删改查、优先级调整）
  - 实现节点健康检查和自动故障转移
  - 修复Retrofit baseUrl处理问题（使用拦截器动态替换URL）
  - 添加RPC节点可用性验证（创建前验证）
  - 默认节点作为兜底，不返回给前端，始终排在最后
  - API健康检查使用动态获取的可用节点

- 前端功能：
  - 添加RPC节点设置页面
  - 支持添加、删除、检查节点
  - 支持调整节点优先级
  - 完整的多语言支持（中文简体/繁体、英文）
  - 添加菜单项多语言key

- 数据库：
  - 添加RPC节点配置表迁移脚本

backend/src/main/kotlin/com/wrbug/polymarketbot/controller/system/RpcNodeController.kt

@@ -0,0 +1,366 @@
+package com.wrbug.polymarketbot.controller.system
+
+import com.wrbug.polymarketbot.dto.ApiResponse
+import com.wrbug.polymarketbot.entity.RpcNodeConfig
+import com.wrbug.polymarketbot.enums.ErrorCode
+import com.wrbug.polymarketbot.service.system.AddRpcNodeRequest
+import com.wrbug.polymarketbot.service.system.NodeCheckResult
+import com.wrbug.polymarketbot.service.system.RpcNodeService
+import com.wrbug.polymarketbot.service.system.UpdateRpcNodeRequest
+import org.slf4j.LoggerFactory
+import org.springframework.context.MessageSource
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.*
+
+/**
+ * RPC 节点管理控制器
+ */
+@RestController
+@RequestMapping("/api/system/rpc-nodes")
+class RpcNodeController(
+    private val rpcNodeService: RpcNodeService,
+    private val messageSource: MessageSource
+) {
+    
+    private val logger = LoggerFactory.getLogger(RpcNodeController::class.java)
+    
+    /**
+     * 获取所有节点列表
+     */
+    @PostMapping("/list")
+    fun getAllNodes(@RequestBody request: Map<String, Any>?): ResponseEntity<ApiResponse<List<RpcNodeConfigDto>>> {
+        return try {
+            val nodes = rpcNodeService.getAllNodes()
+            val dtos = nodes.map { it.toDto() }
+            ResponseEntity.ok(ApiResponse.success(dtos))
+        } catch (e: Exception) {
+            logger.error("获取 RPC 节点列表失败: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "获取节点列表失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 添加节点
+     */
+    @PostMapping("/add")
+    fun addNode(@RequestBody request: AddRpcNodeRequest): ResponseEntity<ApiResponse<RpcNodeConfigDto>> {
+        return try {
+            if (request.providerType.isBlank()) {
+                return ResponseEntity.ok(ApiResponse.paramError("服务商类型不能为空"))
+            }
+            if (request.name.isBlank()) {
+                return ResponseEntity.ok(ApiResponse.paramError("节点名称不能为空"))
+            }
+            
+            val result = rpcNodeService.addNode(request)
+            
+            result.fold(
+                onSuccess = { node ->
+                    ResponseEntity.ok(ApiResponse.success(node.toDto()))
+                },
+                onFailure = { e ->
+                    logger.error("添加 RPC 节点失败: ${e.message}", e)
+                    ResponseEntity.ok(ApiResponse.error(
+                        ErrorCode.SERVER_ERROR,
+                        customMsg = "添加节点失败：${e.message}",
+                        messageSource = messageSource
+                    ))
+                }
+            )
+        } catch (e: Exception) {
+            logger.error("添加 RPC 节点异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "添加节点失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 更新节点
+     */
+    @PostMapping("/update")
+    fun updateNode(@RequestBody request: UpdateRpcNodeRequest): ResponseEntity<ApiResponse<RpcNodeConfigDto>> {
+        return try {
+            val result = rpcNodeService.updateNode(request)
+            
+            result.fold(
+                onSuccess = { node ->
+                    ResponseEntity.ok(ApiResponse.success(node.toDto()))
+                },
+                onFailure = { e ->
+                    logger.error("更新 RPC 节点失败: ${e.message}", e)
+                    ResponseEntity.ok(ApiResponse.error(
+                        ErrorCode.SERVER_ERROR,
+                        customMsg = "更新节点失败：${e.message}",
+                        messageSource = messageSource
+                    ))
+                }
+            )
+        } catch (e: Exception) {
+            logger.error("更新 RPC 节点异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "更新节点失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 删除节点
+     */
+    @PostMapping("/delete")
+    fun deleteNode(@RequestBody request: DeleteRpcNodeRequest): ResponseEntity<ApiResponse<Unit>> {
+        return try {
+            val result = rpcNodeService.deleteNode(request.id)
+            
+            result.fold(
+                onSuccess = {
+                    ResponseEntity.ok(ApiResponse.success(Unit))
+                },
+                onFailure = { e ->
+                    logger.error("删除 RPC 节点失败: ${e.message}", e)
+                    ResponseEntity.ok(ApiResponse.error(
+                        ErrorCode.SERVER_ERROR,
+                        customMsg = "删除节点失败：${e.message}",
+                        messageSource = messageSource
+                    ))
+                }
+            )
+        } catch (e: Exception) {
+            logger.error("删除 RPC 节点异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "删除节点失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 更新节点优先级
+     */
+    @PostMapping("/update-priority")
+    fun updatePriority(@RequestBody request: UpdatePriorityRequest): ResponseEntity<ApiResponse<Unit>> {
+        return try {
+            val result = rpcNodeService.updatePriority(request.id, request.priority)
+            
+            result.fold(
+                onSuccess = {
+                    ResponseEntity.ok(ApiResponse.success(Unit))
+                },
+                onFailure = { e ->
+                    logger.error("更新节点优先级失败: ${e.message}", e)
+                    ResponseEntity.ok(ApiResponse.error(
+                        ErrorCode.SERVER_ERROR,
+                        customMsg = "更新优先级失败：${e.message}",
+                        messageSource = messageSource
+                    ))
+                }
+            )
+        } catch (e: Exception) {
+            logger.error("更新节点优先级异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "更新优先级失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 检查节点健康状态
+     */
+    @PostMapping("/check-health")
+    fun checkHealth(@RequestBody request: CheckHealthRequest): ResponseEntity<ApiResponse<Any>> {
+        return try {
+            if (request.id != null) {
+                // 检查单个节点
+                val result = rpcNodeService.checkNodeHealth(request.id)
+                result.fold(
+                    onSuccess = { checkResult ->
+                        ResponseEntity.ok(ApiResponse.success(checkResult.toDto()))
+                    },
+                    onFailure = { e ->
+                        logger.error("检查节点健康状态失败: ${e.message}", e)
+                        ResponseEntity.ok(ApiResponse.error(
+                            ErrorCode.SERVER_ERROR,
+                            customMsg = "检查节点失败：${e.message}",
+                            messageSource = messageSource
+                        ))
+                    }
+                )
+            } else {
+                // 批量检查所有节点
+                val result = rpcNodeService.checkAllNodesHealth()
+                result.fold(
+                    onSuccess = { checkResults ->
+                        val dtos = checkResults.mapValues { it.value.toDto() }
+                        ResponseEntity.ok(ApiResponse.success(dtos))
+                    },
+                    onFailure = { e ->
+                        logger.error("批量检查节点健康状态失败: ${e.message}", e)
+                        ResponseEntity.ok(ApiResponse.error(
+                            ErrorCode.SERVER_ERROR,
+                            customMsg = "批量检查节点失败：${e.message}",
+                            messageSource = messageSource
+                        ))
+                    }
+                )
+            }
+        } catch (e: Exception) {
+            logger.error("检查节点健康状态异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.error(
+                ErrorCode.SERVER_ERROR,
+                customMsg = "检查节点失败：${e.message}",
+                messageSource = messageSource
+            ))
+        }
+    }
+    
+    /**
+     * 校验节点（添加前）
+     */
+    @PostMapping("/validate")
+    fun validateNode(@RequestBody request: AddRpcNodeRequest): ResponseEntity<ApiResponse<ValidateNodeResponse>> {
+        return try {
+            if (request.providerType.isBlank()) {
+                return ResponseEntity.ok(ApiResponse.paramError("服务商类型不能为空"))
+            }
+            if (request.name.isBlank()) {
+                return ResponseEntity.ok(ApiResponse.paramError("节点名称不能为空"))
+            }
+            
+            // 临时创建节点配置以进行验证（不保存到数据库）
+            // 这里直接复用 addNode 的部分逻辑，但只进行校验
+            val result = rpcNodeService.addNode(request)
+            
+            result.fold(
+                onSuccess = { node ->
+                    // 添加成功后立即删除（这只是为了校验）
+                    rpcNodeService.deleteNode(node.id!!)
+                    ResponseEntity.ok(ApiResponse.success(ValidateNodeResponse(
+                        valid = true,
+                        message = "节点可用",
+                        responseTimeMs = node.responseTimeMs
+                    )))
+                },
+                onFailure = { e ->
+                    ResponseEntity.ok(ApiResponse.success(ValidateNodeResponse(
+                        valid = false,
+                        message = e.message ?: "节点验证失败",
+                        responseTimeMs = null
+                    )))
+                }
+            )
+        } catch (e: Exception) {
+            logger.error("验证节点异常: ${e.message}", e)
+            ResponseEntity.ok(ApiResponse.success(ValidateNodeResponse(
+                valid = false,
+                message = e.message ?: "节点验证失败",
+                responseTimeMs = null
+            )))
+        }
+    }
+}
+
+/**
+ * RPC 节点配置 DTO
+ */
+data class RpcNodeConfigDto(
+    val id: Long?,
+    val providerType: String,
+    val name: String,
+    val httpUrl: String,
+    val wsUrl: String?,
+    val apiKeyMasked: String?,  // 脱敏后的 API Key
+    val enabled: Boolean,
+    val priority: Int,
+    val lastCheckTime: Long?,
+    val lastCheckStatus: String?,
+    val responseTimeMs: Int?,
+    val createdAt: Long,
+    val updatedAt: Long
+)
+
+/**
+ * 节点检查结果 DTO
+ */
+data class NodeCheckResultDto(
+    val status: String,
+    val message: String,
+    val checkTime: Long,
+    val responseTimeMs: Int?,
+    val blockNumber: String?
+)
+
+/**
+ * 验证节点响应
+ */
+data class ValidateNodeResponse(
+    val valid: Boolean,
+    val message: String,
+    val responseTimeMs: Int?
+)
+
+/**
+ * 删除节点请求
+ */
+data class DeleteRpcNodeRequest(
+    val id: Long
+)
+
+/**
+ * 更新优先级请求
+ */
+data class UpdatePriorityRequest(
+    val id: Long,
+    val priority: Int
+)
+
+/**
+ * 检查健康状态请求
+ */
+data class CheckHealthRequest(
+    val id: Long? = null  // 如果为 null，则检查所有节点
+)
+
+/**
+ * 扩展函数：将 RpcNodeConfig 转换为 DTO
+ */
+private fun RpcNodeConfig.toDto(): RpcNodeConfigDto {
+    return RpcNodeConfigDto(
+        id = id,
+        providerType = providerType,
+        name = name,
+        httpUrl = httpUrl,
+        wsUrl = wsUrl,
+        apiKeyMasked = apiKey?.let { "***" },  // 脱敏显示
+        enabled = enabled,
+        priority = priority,
+        lastCheckTime = lastCheckTime,
+        lastCheckStatus = lastCheckStatus,
+        responseTimeMs = responseTimeMs,
+        createdAt = createdAt,
+        updatedAt = updatedAt
+    )
+}
+
+/**
+ * 扩展函数：将 NodeCheckResult 转换为 DTO
+ */
+private fun NodeCheckResult.toDto(): NodeCheckResultDto {
+    return NodeCheckResultDto(
+        status = status.name,
+        message = message,
+        checkTime = checkTime,
+        responseTimeMs = responseTimeMs,
+        blockNumber = blockNumber
+    )
+}

backend/src/main/kotlin/com/wrbug/polymarketbot/entity/RpcNodeConfig.kt

@@ -0,0 +1,73 @@
+package com.wrbug.polymarketbot.entity
+
+import jakarta.persistence.*
+
+/**
+ * Polygon RPC 节点配置实体
+ * 用于存储用户配置的 RPC 节点信息
+ */
+@Entity
+@Table(name = "rpc_node_config")
+data class RpcNodeConfig(
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    val id: Long? = null,
+    
+    @Column(name = "provider_type", nullable = false, length = 50)
+    val providerType: String,  // 服务商类型: ALCHEMY, INFURA, QUICKNODE, CHAINSTACK, GETBLOCK, CUSTOM, PUBLIC
+    
+    @Column(name = "name", nullable = false, length = 100)
+    val name: String,  // 节点名称
+    
+    @Column(name = "http_url", nullable = false, length = 500)
+    val httpUrl: String,  // HTTP RPC URL
+    
+    @Column(name = "ws_url", length = 500)
+    val wsUrl: String? = null,  // WebSocket URL (可选)
+    
+    @Column(name = "api_key", length = 200)
+    val apiKey: String? = null,  // API Key (加密存储)
+    
+    @Column(name = "enabled", nullable = false)
+    var enabled: Boolean = true,  // 是否启用
+    
+    @Column(name = "priority", nullable = false)
+    var priority: Int = 0,  // 优先级(数字越小优先级越高)
+    
+    @Column(name = "last_check_time")
+    var lastCheckTime: Long? = null,  // 最后检查时间(毫秒时间戳)
+    
+    @Column(name = "last_check_status", length = 20)
+    var lastCheckStatus: String? = null,  // 最后检查状态: HEALTHY, UNHEALTHY, UNKNOWN
+    
+    @Column(name = "response_time_ms")
+    var responseTimeMs: Int? = null,  // 最后一次响应时间(毫秒)
+    
+    @Column(name = "created_at", nullable = false)
+    val createdAt: Long = System.currentTimeMillis(),
+    
+    @Column(name = "updated_at", nullable = false)
+    var updatedAt: Long = System.currentTimeMillis()
+)
+
+/**
+ * RPC 节点健康状态枚举
+ */
+enum class NodeHealthStatus {
+    HEALTHY,    // 健康
+    UNHEALTHY,  // 不健康
+    UNKNOWN     // 未知
+}
+
+/**
+ * RPC 节点服务商类型枚举
+ */
+enum class RpcProviderType {
+    ALCHEMY,
+    INFURA,
+    QUICKNODE,
+    CHAINSTACK,
+    GETBLOCK,
+    CUSTOM,
+    PUBLIC
+}

backend/src/main/kotlin/com/wrbug/polymarketbot/repository/RpcNodeConfigRepository.kt

@@ -0,0 +1,23 @@
+package com.wrbug.polymarketbot.repository
+
+import com.wrbug.polymarketbot.entity.RpcNodeConfig
+import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.stereotype.Repository
+
+@Repository
+interface RpcNodeConfigRepository : JpaRepository<RpcNodeConfig, Long> {
+    /**
+     * 查询所有已启用的节点,按优先级排序(优先级数字越小越靠前)
+     */
+    fun findAllByEnabledTrueOrderByPriorityAsc(): List<RpcNodeConfig>
+    
+    /**
+     * 查询指定 ID 的已启用节点
+     */
+    fun findByIdAndEnabledTrue(id: Long): RpcNodeConfig?
+    
+    /**
+     * 查询所有节点,按优先级排序
+     */
+    fun findAllByOrderByPriorityAsc(): List<RpcNodeConfig>
+}

backend/src/main/kotlin/com/wrbug/polymarketbot/service/common/BlockchainService.kt

@@ -12,6 +12,7 @@ import com.wrbug.polymarketbot.util.createClient
 import org.slf4j.LoggerFactory
 import org.springframework.beans.factory.annotation.Value
 import com.wrbug.polymarketbot.service.system.RelayClientService
+import com.wrbug.polymarketbot.service.system.RpcNodeService
 import org.springframework.stereotype.Service
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
@@ -26,10 +27,9 @@ import java.math.BigInteger
 class BlockchainService(
     @Value("\${polymarket.data-api.base-url:https://data-api.polymarket.com}")
     private val dataApiBaseUrl: String,
-    @Value("\${polygon.rpc.url:}")
-    private val polygonRpcUrl: String,
     private val retrofitFactory: RetrofitFactory,
-    private val relayClientService: RelayClientService
+    private val relayClientService: RelayClientService,
+    private val rpcNodeService: RpcNodeService
 ) {
     
     private val logger = LoggerFactory.getLogger(BlockchainService::class.java)
@@ -69,12 +69,9 @@ class BlockchainService(
             .create(PolymarketDataApi::class.java)
     }
     
-    private val polygonRpcApi: EthereumRpcApi? by lazy {
-        if (polygonRpcUrl.isBlank()) {
-            null
-        } else {
-            retrofitFactory.createEthereumRpcApi(polygonRpcUrl)
-        }
+    private val polygonRpcApi: EthereumRpcApi by lazy {
+        val rpcUrl = rpcNodeService.getHttpUrl()
+        retrofitFactory.createEthereumRpcApi(rpcUrl)
     }
     
     /**
@@ -85,13 +82,7 @@ class BlockchainService(
      */
     suspend fun getProxyAddress(walletAddress: String): Result<String> {
         return try {
-            // 如果未配置 RPC URL，返回错误
-            if (polygonRpcUrl.isBlank()) {
-                logger.warn("未配置 Polygon RPC URL，无法获取代理地址")
-                return Result.failure(IllegalStateException("未配置 Polygon RPC URL，无法获取代理地址。请在配置文件中设置 polygon.rpc.url 环境变量"))
-            }
-            
-            val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+            val rpcApi = polygonRpcApi
             
             // 计算函数选择器
             val functionSelector = EthereumUtils.getFunctionSelector(computeProxyAddressFunctionSignature)
@@ -147,12 +138,6 @@ class BlockchainService(
      */
     suspend fun getUsdcBalance(walletAddress: String, proxyAddress: String): Result<String> {
         return try {
-            // 如果未配置 RPC URL，返回错误
-            if (polygonRpcUrl.isBlank()) {
-                logger.warn("未配置 Polygon RPC URL，无法查询 USDC 余额")
-                return Result.failure(IllegalStateException("未配置 Polygon RPC URL，无法查询 USDC 余额。请在配置文件中设置 polygon.rpc.url 环境变量"))
-            }
-            
             // 检查代理地址是否为空
             if (proxyAddress.isBlank()) {
                 logger.error("代理地址为空，无法查询余额")
@@ -173,7 +158,7 @@ class BlockchainService(
      * 通过 RPC 查询 USDC 余额
      */
     private suspend fun queryUsdcBalanceViaRpc(walletAddress: String): String {
-        val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+        val rpcApi = polygonRpcApi
         
         // 构建 ERC-20 balanceOf 函数调用
         // function signature: balanceOf(address) -> bytes4(0x70a08231)
@@ -264,13 +249,7 @@ class BlockchainService(
      */
     suspend fun getTokenId(conditionId: String, outcomeIndex: Int): Result<String> {
         return try {
-            // 如果未配置 RPC URL，返回错误
-            if (polygonRpcUrl.isBlank()) {
-                logger.warn("未配置 Polygon RPC URL，无法计算 tokenId")
-                return Result.failure(IllegalStateException("未配置 Polygon RPC URL，无法计算 tokenId"))
-            }
-            
-            val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+            val rpcApi = polygonRpcApi
             
             // 验证 outcomeIndex
             if (outcomeIndex < 0) {
@@ -449,7 +428,7 @@ class BlockchainService(
      * 获取代理钱包的 nonce（用于构建 Safe 交易）
      */
     private suspend fun getProxyNonce(proxyAddress: String): Result<BigInteger> {
-        val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+        val rpcApi = polygonRpcApi
         
         // Gnosis Safe 的 nonce 通过调用合约的 nonce() 函数获取
         val nonceFunctionSelector = EthereumUtils.getFunctionSelector("nonce()")
@@ -484,7 +463,7 @@ class BlockchainService(
      * 获取交易 nonce
      */
     private suspend fun getTransactionCount(address: String): Result<BigInteger> {
-        val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+        val rpcApi = polygonRpcApi
         
         val rpcRequest = JsonRpcRequest(
             method = "eth_getTransactionCount",
@@ -512,7 +491,7 @@ class BlockchainService(
      * 获取 gas price
      */
     private suspend fun getGasPrice(): Result<BigInteger> {
-        val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+        val rpcApi = polygonRpcApi
         
         val rpcRequest = JsonRpcRequest(
             method = "eth_gasPrice",
@@ -614,11 +593,7 @@ class BlockchainService(
      */
     suspend fun getTransactionDetails(txHash: String): Result<String> {
         return try {
-            if (polygonRpcUrl.isBlank()) {
-                return Result.failure(IllegalStateException("未配置 Polygon RPC URL"))
-            }
-            
-            val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+            val rpcApi = polygonRpcApi
             
             // 查询交易
             val txRequest = JsonRpcRequest(

backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/ApiHealthCheckService.kt

@@ -33,7 +33,8 @@ class ApiHealthCheckService(
     @Value("\${polymarket.rtds.ws-url}")
     private val polymarketWsUrl: String,
     @Value("\${polymarket.builder.relayer-url:}")
-    private val builderRelayerUrl: String
+    private val builderRelayerUrl: String,
+    private val rpcNodeService: RpcNodeService
 ) : ApplicationContextAware {
 
     private var applicationContext: ApplicationContext? = null
@@ -186,19 +187,28 @@ class ApiHealthCheckService(
 
     /**
      * 检查 Polygon RPC
+     * 使用动态获取的可用节点，而不是固定的配置
      */
     private suspend fun checkPolygonRpc(): ApiHealthCheckDto = withContext(Dispatchers.IO) {
-        if (polygonRpcUrl.isBlank()) {
-            return@withContext ApiHealthCheckDto(
-                name = "Polygon RPC",
-                url = "未配置",
-                status = "skipped",
-                message = "未配置 Polygon RPC URL"
-            )
+        // 优先使用动态获取的可用节点
+        val rpcUrl = try {
+            rpcNodeService.getHttpUrl()
+        } catch (e: Exception) {
+            logger.debug("获取可用 RPC 节点失败，使用配置的默认值: ${e.message}")
+            // 如果获取失败，使用配置的默认值作为兜底
+            if (polygonRpcUrl.isNotBlank()) {
+                polygonRpcUrl
+            } else {
+                return@withContext ApiHealthCheckDto(
+                    name = "Polygon RPC",
+                    url = "未配置",
+                    status = "skipped",
+                    message = "未配置 Polygon RPC URL 且没有可用的节点"
+                )
+            }
         }
-
-        val url = polygonRpcUrl
-        checkJsonRpcApi("Polygon RPC", url)
+        
+        checkJsonRpcApi("Polygon RPC", rpcUrl)
     }
 
     /**

backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/RelayClientService.kt

@@ -24,12 +24,11 @@ import java.math.BigInteger
  */
 @Service
 class RelayClientService(
-    @Value("\${polygon.rpc.url:}")
-    private val polygonRpcUrl: String,
     @Value("\${polymarket.builder.relayer-url:}")
     private val builderRelayerUrl: String,
     private val retrofitFactory: RetrofitFactory,
-    private val systemConfigService: SystemConfigService
+    private val systemConfigService: SystemConfigService,
+    private val rpcNodeService: RpcNodeService
 ) {
 
     private val logger = LoggerFactory.getLogger(RelayClientService::class.java)
@@ -43,12 +42,9 @@ class RelayClientService(
     // 空集合ID
     private val EMPTY_SET = "0x0000000000000000000000000000000000000000000000000000000000000000"
 
-    private val polygonRpcApi: EthereumRpcApi? by lazy {
-        if (polygonRpcUrl.isBlank()) {
-            null
-        } else {
-            retrofitFactory.createEthereumRpcApi(polygonRpcUrl)
-        }
+    private val polygonRpcApi: EthereumRpcApi by lazy {
+        val rpcUrl = rpcNodeService.getHttpUrl()
+        retrofitFactory.createEthereumRpcApi(rpcUrl)
     }
 
     /**
@@ -260,7 +256,7 @@ class RelayClientService(
         builderSecret: String,
         builderPassphrase: String
     ): Result<String> {
-        val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+        val rpcApi = polygonRpcApi
         val relayerApi = retrofitFactory.createBuilderRelayerApi(
             relayerUrl = builderRelayerUrl,
             apiKey = builderApiKey,
@@ -461,13 +457,7 @@ class RelayClientService(
         safeTx: SafeTransaction
     ): Result<String> {
         return try {
-            // 如果未配置 RPC URL，返回错误
-            if (polygonRpcUrl.isBlank()) {
-                logger.warn("未配置 Polygon RPC URL，无法执行交易")
-                return Result.failure(IllegalStateException("未配置 Polygon RPC URL，无法执行交易。请配置 polygon.rpc.url 或启用 Builder Relayer（Gasless）"))
-            }
-
-            val rpcApi = polygonRpcApi ?: throw IllegalStateException("Polygon RPC URL 未配置")
+            val rpcApi = polygonRpcApi
 
             // 从私钥推导实际签名地址（交易真正的 from 地址）
             val cleanPrivateKey = privateKey.removePrefix("0x")

backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/RpcNodeService.kt

@@ -0,0 +1,509 @@
+package com.wrbug.polymarketbot.service.system
+
+import com.wrbug.polymarketbot.api.EthereumRpcApi
+import com.wrbug.polymarketbot.api.JsonRpcRequest
+import com.wrbug.polymarketbot.entity.NodeHealthStatus
+import com.wrbug.polymarketbot.entity.RpcNodeConfig
+import com.wrbug.polymarketbot.entity.RpcProviderType
+import com.wrbug.polymarketbot.repository.RpcNodeConfigRepository
+import com.wrbug.polymarketbot.util.CryptoUtils
+import com.wrbug.polymarketbot.util.RetrofitFactory
+import org.slf4j.LoggerFactory
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+
+/**
+ * RPC 节点管理服务
+ * 负责管理用户配置的 Polygon RPC 节点
+ */
+@Service
+class RpcNodeService(
+    private val rpcNodeConfigRepository: RpcNodeConfigRepository,
+    private val cryptoUtils: CryptoUtils,
+    private val retrofitFactory: RetrofitFactory
+) {
+    
+    private val logger = LoggerFactory.getLogger(RpcNodeService::class.java)
+    
+    companion object {
+        // 默认公共节点
+        private const val DEFAULT_RPC_URL = "https://polygon.publicnode.com"
+        private const val DEFAULT_WS_URL = "wss://polygon.publicnode.com"
+        
+        // 主流服务商 URL 模板
+        private val PROVIDER_HTTP_TEMPLATES = mapOf(
+            RpcProviderType.ALCHEMY to "https://polygon-mainnet.g.alchemy.com/v2/{apiKey}",
+            RpcProviderType.INFURA to "https://polygon-mainnet.infura.io/v3/{apiKey}",
+            RpcProviderType.QUICKNODE to "https://your-endpoint.quiknode.pro/{apiKey}/",
+            RpcProviderType.CHAINSTACK to "https://polygon-mainnet.core.chainstack.com/{apiKey}",
+            RpcProviderType.GETBLOCK to "https://go.getblock.io/{apiKey}/"
+        )
+        
+        private val PROVIDER_WS_TEMPLATES = mapOf(
+            RpcProviderType.ALCHEMY to "wss://polygon-mainnet.g.alchemy.com/v2/{apiKey}",
+            RpcProviderType.INFURA to "wss://polygon-mainnet.infura.io/ws/v3/{apiKey}",
+            RpcProviderType.QUICKNODE to "wss://your-endpoint.quiknode.pro/{apiKey}/",
+            RpcProviderType.CHAINSTACK to "wss://ws-polygon-mainnet.core.chainstack.com/{apiKey}",
+            RpcProviderType.GETBLOCK to "wss://go.getblock.io/{apiKey}/"
+        )
+    }
+    
+    /**
+     * 获取所有节点配置（不包含默认节点）
+     * 默认节点作为兜底，不应该返回给前端
+     */
+    fun getAllNodes(): List<RpcNodeConfig> {
+        val allNodes = rpcNodeConfigRepository.findAllByOrderByPriorityAsc()
+        
+        // 过滤掉默认节点，只返回用户配置的节点
+        return allNodes.filterNot { isDefaultNode(it) }
+    }
+    
+    /**
+     * 获取所有节点配置（包含默认节点，用于内部使用）
+     * 默认节点始终排在最后
+     */
+    fun getAllNodesWithDefault(): List<RpcNodeConfig> {
+        val allNodes = rpcNodeConfigRepository.findAllByOrderByPriorityAsc()
+        
+        // 分离默认节点和用户配置的节点
+        val (defaultNodes, userNodes) = allNodes.partition { isDefaultNode(it) }
+        
+        // 返回用户配置的节点，默认节点排在最后（如果存在）
+        return userNodes + defaultNodes
+    }
+    
+    /**
+     * 判断是否是默认节点
+     */
+    private fun isDefaultNode(node: RpcNodeConfig): Boolean {
+        return node.httpUrl == DEFAULT_RPC_URL || 
+               node.httpUrl == DEFAULT_RPC_URL.removeSuffix("/") ||
+               (node.providerType == RpcProviderType.PUBLIC.name && 
+                (node.httpUrl.contains("polygon.publicnode.com") || 
+                 node.httpUrl.contains("publicnode.com")))
+    }
+    
+    /**
+     * 获取第一个可用的节点
+     * 按优先级顺序遍历所有启用的节点，找到第一个真正可用的节点
+     * 如果所有节点都不可用，返回默认节点
+     * @return  可用节点的配置,如果没有可用节点则返回失败
+     */
+    fun getAvailableNode(): Result<RpcNodeConfig> {
+        return try {
+            val nodes = rpcNodeConfigRepository.findAllByEnabledTrueOrderByPriorityAsc()
+                .filterNot { isDefaultNode(it) }  // 排除默认节点
+            
+            if (nodes.isEmpty()) {
+                logger.warn("没有配置任何 RPC 节点,使用默认节点: $DEFAULT_RPC_URL")
+                return Result.failure(IllegalStateException("没有配置任何 RPC 节点"))
+            }
+            
+            // 优先使用最近检查状态为 HEALTHY 的节点
+            val healthyNodes = nodes.filter { 
+                it.lastCheckStatus == NodeHealthStatus.HEALTHY.name 
+            }
+            
+            // 先尝试使用健康的节点（按优先级排序）
+            for (node in healthyNodes) {
+                try {
+                    // 快速验证节点是否仍然可用（使用较短的超时时间）
+                    val checkResult = validateNode(node.httpUrl, node.wsUrl).getOrNull()
+                    if (checkResult != null && checkResult.status == NodeHealthStatus.HEALTHY) {
+                        logger.debug("使用健康的 RPC 节点: ${node.name} (${node.httpUrl})")
+                        return Result.success(node)
+                    }
+                } catch (e: Exception) {
+                    logger.debug("节点 ${node.name} 验证失败，尝试下一个节点: ${e.message}")
+                    // 继续尝试下一个节点
+                }
+            }
+            
+            // 如果没有健康的节点，尝试验证所有节点（按优先级）
+            for (node in nodes) {
+                try {
+                    val checkResult = validateNode(node.httpUrl, node.wsUrl).getOrNull()
+                    if (checkResult != null && checkResult.status == NodeHealthStatus.HEALTHY) {
+                        logger.info("找到可用的 RPC 节点: ${node.name} (${node.httpUrl})")
+                        return Result.success(node)
+                    }
+                } catch (e: Exception) {
+                    logger.debug("节点 ${node.name} 验证失败，尝试下一个节点: ${e.message}")
+                    // 继续尝试下一个节点
+                }
+            }
+            
+            // 所有节点都不可用，返回失败
+            logger.warn("所有 RPC 节点都不可用，将使用默认节点: $DEFAULT_RPC_URL")
+            Result.failure(IllegalStateException("所有 RPC 节点都不可用"))
+        } catch (e: Exception) {
+            logger.error("获取可用节点失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 获取节点的 HTTP URL (如果没有配置,使用默认节点)
+     */
+    fun getHttpUrl(): String {
+        val nodeResult = getAvailableNode()
+        return if (nodeResult.isSuccess) {
+            nodeResult.getOrNull()?.httpUrl ?: DEFAULT_RPC_URL
+        } else {
+            logger.warn("没有可用的用户配置节点,使用默认节点")
+            DEFAULT_RPC_URL
+        }
+    }
+    
+    /**
+     * 获取节点的 WebSocket URL (如果没有配置,使用默认节点)
+     */
+    fun getWsUrl(): String {
+        val nodeResult = getAvailableNode()
+        return if (nodeResult.isSuccess) {
+            nodeResult.getOrNull()?.wsUrl ?: DEFAULT_WS_URL
+        } else {
+            logger.warn("没有可用的用户配置节点,使用默认 WS 节点")
+            DEFAULT_WS_URL
+        }
+    }
+    
+    /**
+     * 添加节点
+     */
+    @Transactional
+    fun addNode(request: AddRpcNodeRequest): Result<RpcNodeConfig> {
+        return try {
+            // 1. 验证请求
+            val providerType = try {
+                RpcProviderType.valueOf(request.providerType.uppercase())
+            } catch (e: IllegalArgumentException) {
+                return Result.failure(IllegalArgumentException("不支持的服务商类型: ${request.providerType}"))
+            }
+            
+            // 2. 构建 HTTP 和 WS URL
+            val (httpUrl, wsUrl) = if (providerType == RpcProviderType.CUSTOM) {
+                // 自定义节点,使用用户提供的 URL
+                if (request.httpUrl.isNullOrBlank()) {
+                    return Result.failure(IllegalArgumentException("自定义节点必须提供 HTTP URL"))
+                }
+                Pair(request.httpUrl, request.wsUrl)
+            } else {
+                // 主流服务商,使用模板生成 URL
+                if (request.apiKey.isNullOrBlank()) {
+                    return Result.failure(IllegalArgumentException("${request.providerType} 节点必须提供 API Key"))
+                }
+                val httpTemplate = PROVIDER_HTTP_TEMPLATES[providerType]
+                    ?: return Result.failure(IllegalArgumentException("未找到 ${request.providerType} 的 HTTP URL 模板"))
+                val wsTemplate = PROVIDER_WS_TEMPLATES[providerType]
+                Pair(
+                    httpTemplate.replace("{apiKey}", request.apiKey),
+                    wsTemplate?.replace("{apiKey}", request.apiKey)
+                )
+            }
+            
+            // 3. 校验节点可用性
+            val validationResult = validateNode(httpUrl, wsUrl)
+            if (validationResult.isFailure) {
+                return Result.failure(validationResult.exceptionOrNull() ?: Exception("节点验证失败"))
+            }
+            
+            val checkResult = validationResult.getOrNull()!!
+            
+            // 检查节点是否健康，如果不健康则不允许添加
+            if (checkResult.status != NodeHealthStatus.HEALTHY) {
+                return Result.failure(IllegalArgumentException("节点不可用: ${checkResult.message}"))
+            }
+            
+            // 4. 加密 API Key (如果有)
+            val encryptedApiKey = request.apiKey?.let { cryptoUtils.encrypt(it) }
+            
+            // 5. 获取当前最大优先级
+            val maxPriority = rpcNodeConfigRepository.findAllByOrderByPriorityAsc()
+                .maxOfOrNull { it.priority } ?: 0
+            
+            // 6. 创建节点配置
+            val node = RpcNodeConfig(
+                providerType = providerType.name,
+                name = request.name,
+                httpUrl = httpUrl,
+                wsUrl = wsUrl,
+                apiKey = encryptedApiKey,
+                enabled = true,
+                priority = maxPriority + 1,  // 新节点放到最后
+                lastCheckTime = checkResult.checkTime,
+                lastCheckStatus = checkResult.status.name,
+                responseTimeMs = checkResult.responseTimeMs
+            )
+            
+            val savedNode = rpcNodeConfigRepository.save(node)
+            logger.info("成功添加 RPC 节点: ${savedNode.name} (${savedNode.httpUrl})")
+            Result.success(savedNode)
+        } catch (e: Exception) {
+            logger.error("添加节点失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 更新节点
+     * 默认节点不允许更新（作为兜底，不应该返回给前端）
+     */
+    @Transactional
+    fun updateNode(request: UpdateRpcNodeRequest): Result<RpcNodeConfig> {
+        return try {
+            val node = rpcNodeConfigRepository.findById(request.id).orElse(null)
+                ?: return Result.failure(IllegalArgumentException("节点不存在: ${request.id}"))
+            
+            // 如果是默认节点，不允许更新
+            if (isDefaultNode(node)) {
+                return Result.failure(IllegalArgumentException("默认节点不允许更新"))
+            }
+            
+            // 更新字段
+            val updatedNode = node.copy(
+                name = request.name ?: node.name,
+                enabled = request.enabled ?: node.enabled,
+                priority = request.priority ?: node.priority,
+                updatedAt = System.currentTimeMillis()
+            )
+            
+            val savedNode = rpcNodeConfigRepository.save(updatedNode)
+            logger.info("成功更新 RPC 节点: ${savedNode.name}")
+            Result.success(savedNode)
+        } catch (e: Exception) {
+            logger.error("更新节点失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 删除节点
+     * 默认节点不允许删除（作为兜底，不应该返回给前端）
+     */
+    @Transactional
+    fun deleteNode(id: Long): Result<Unit> {
+        return try {
+            val node = rpcNodeConfigRepository.findById(id).orElse(null)
+                ?: return Result.failure(IllegalArgumentException("节点不存在: $id"))
+            
+            // 如果是默认节点，不允许删除
+            if (isDefaultNode(node)) {
+                return Result.failure(IllegalArgumentException("默认节点不允许删除"))
+            }
+            
+            rpcNodeConfigRepository.delete(node)
+            logger.info("成功删除 RPC 节点: ${node.name}")
+            Result.success(Unit)
+        } catch (e: Exception) {
+            logger.error("删除节点失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 更新节点优先级
+     * 默认节点不允许更新优先级（作为兜底，始终排在最后）
+     */
+    @Transactional
+    fun updatePriority(id: Long, priority: Int): Result<Unit> {
+        return try {
+            val node = rpcNodeConfigRepository.findById(id).orElse(null)
+                ?: return Result.failure(IllegalArgumentException("节点不存在: $id"))
+            
+            // 如果是默认节点，不允许更新优先级
+            if (isDefaultNode(node)) {
+                return Result.failure(IllegalArgumentException("默认节点不允许更新优先级"))
+            }
+            
+            val updatedNode = node.copy(
+                priority = priority,
+                updatedAt = System.currentTimeMillis()
+            )
+            
+            rpcNodeConfigRepository.save(updatedNode)
+            logger.info("成功更新节点优先级: ${node.name} -> $priority")
+            Result.success(Unit)
+        } catch (e: Exception) {
+            logger.error("更新节点优先级失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 检查单个节点健康状态
+     * 默认节点不应该被检查（作为兜底，不应该返回给前端）
+     */
+    @Transactional
+    fun checkNodeHealth(nodeId: Long): Result<NodeCheckResult> {
+        return try {
+            val node = rpcNodeConfigRepository.findById(nodeId).orElse(null)
+                ?: return Result.failure(IllegalArgumentException("节点不存在: $nodeId"))
+            
+            // 如果是默认节点，不允许检查
+            if (isDefaultNode(node)) {
+                return Result.failure(IllegalArgumentException("默认节点不允许检查"))
+            }
+            
+            val checkResult = validateNode(node.httpUrl, node.wsUrl).getOrThrow()
+            
+            // 更新节点健康状态
+            val updatedNode = node.copy(
+                lastCheckTime = checkResult.checkTime,
+                lastCheckStatus = checkResult.status.name,
+                responseTimeMs = checkResult.responseTimeMs,
+                updatedAt = System.currentTimeMillis()
+            )
+            
+            rpcNodeConfigRepository.save(updatedNode)
+            logger.info("检查节点健康状态: ${node.name} -> ${checkResult.status}")
+            Result.success(checkResult)
+        } catch (e: Exception) {
+            logger.error("检查节点健康状态失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 批量检查所有节点健康状态（不包含默认节点）
+     * 默认节点作为兜底，不应该返回给前端
+     */
+    @Transactional
+    fun checkAllNodesHealth(): Result<Map<Long, NodeCheckResult>> {
+        return try {
+            val allNodes = rpcNodeConfigRepository.findAll()
+            // 过滤掉默认节点，只检查用户配置的节点
+            val nodes = allNodes.filterNot { isDefaultNode(it) }
+            val results = mutableMapOf<Long, NodeCheckResult>()
+            
+            for (node in nodes) {
+                try {
+                    val checkResult = validateNode(node.httpUrl, node.wsUrl).getOrNull()
+                    if (checkResult != null) {
+                        results[node.id!!] = checkResult
+                        
+                        // 更新节点状态
+                        val updatedNode = node.copy(
+                            lastCheckTime = checkResult.checkTime,
+                            lastCheckStatus = checkResult.status.name,
+                            responseTimeMs = checkResult.responseTimeMs,
+                            updatedAt = System.currentTimeMillis()
+                        )
+                        rpcNodeConfigRepository.save(updatedNode)
+                    }
+                } catch (e: Exception) {
+                    logger.error("检查节点 ${node.name} 失败: ${e.message}", e)
+                }
+            }
+            
+            Result.success(results)
+        } catch (e: Exception) {
+            logger.error("批量检查节点健康状态失败: ${e.message}", e)
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 校验节点可用性
+     * 调用 eth_blockNumber 验证节点是否可用
+     */
+    private fun validateNode(httpUrl: String, wsUrl: String?): Result<NodeCheckResult> {
+        return try {
+            logger.debug("开始验证节点: $httpUrl")
+            
+            // 创建临时 RPC API
+            val rpcApi = retrofitFactory.createEthereumRpcApi(httpUrl)
+            
+            // 调用 eth_blockNumber
+            val startTime = System.currentTimeMillis()
+            val rpcRequest = JsonRpcRequest(
+                method = "eth_blockNumber",
+                params = emptyList()
+            )
+            
+            val response = kotlinx.coroutines.runBlocking { rpcApi.call(rpcRequest) }
+            val responseTime = (System.currentTimeMillis() - startTime).toInt()
+            
+            if (!response.isSuccessful || response.body() == null) {
+                logger.warn("节点验证失败: HTTP ${response.code()}")
+                return Result.success(NodeCheckResult(
+                    status = NodeHealthStatus.UNHEALTHY,
+                    message = "HTTP 请求失败: ${response.code()}",
+                    checkTime = System.currentTimeMillis(),
+                    responseTimeMs = responseTime
+                ))
+            }
+            
+            val rpcResponse = response.body()!!
+            if (rpcResponse.error != null) {
+                logger.warn("节点验证失败: RPC 错误 ${rpcResponse.error.message}")
+                return Result.success(NodeCheckResult(
+                    status = NodeHealthStatus.UNHEALTHY,
+                    message = "RPC 错误: ${rpcResponse.error.message}",
+                    checkTime = System.currentTimeMillis(),
+                    responseTimeMs = responseTime
+                ))
+            }
+            
+            val blockNumber = rpcResponse.result
+            if (blockNumber.isNullOrBlank()) {
+                return Result.success(NodeCheckResult(
+                    status = NodeHealthStatus.UNHEALTHY,
+                    message = "区块号为空",
+                    checkTime = System.currentTimeMillis(),
+                    responseTimeMs = responseTime
+                ))
+            }
+            
+            logger.info("节点验证成功: $httpUrl, 区块号: $blockNumber, 响应时间: ${responseTime}ms")
+            Result.success(NodeCheckResult(
+                status = NodeHealthStatus.HEALTHY,
+                message = "节点可用, 当前区块: $blockNumber",
+                checkTime = System.currentTimeMillis(),
+                responseTimeMs = responseTime,
+                blockNumber = blockNumber
+            ))
+        } catch (e: Exception) {
+            logger.error("验证节点失败: ${e.message}", e)
+            Result.success(NodeCheckResult(
+                status = NodeHealthStatus.UNHEALTHY,
+                message = "验证失败: ${e.message}",
+                checkTime = System.currentTimeMillis(),
+                responseTimeMs = null
+            ))
+        }
+    }
+}
+
+/**
+ * 添加节点请求
+ */
+data class AddRpcNodeRequest(
+    val providerType: String,  // ALCHEMY, INFURA, QUICKNODE, CHAINSTACK, GETBLOCK, CUSTOM, PUBLIC
+    val name: String,
+    val apiKey: String? = null,  // 主流服务商需要
+    val httpUrl: String? = null,  // CUSTOM 需要
+    val wsUrl: String? = null
+)
+
+/**
+ * 更新节点请求
+ */
+data class UpdateRpcNodeRequest(
+    val id: Long,
+    val name: String? = null,
+    val enabled: Boolean? = null,
+    val priority: Int? = null
+)
+
+/**
+ * 节点检查结果
+ */
+data class NodeCheckResult(
+    val status: NodeHealthStatus,
+    val message: String,
+    val checkTime: Long,
+    val responseTimeMs: Int?,
+    val blockNumber: String? = null
+)

backend/src/main/kotlin/com/wrbug/polymarketbot/util/RetrofitFactory.kt

@@ -8,9 +8,16 @@ import com.wrbug.polymarketbot.api.GitHubApi
 import com.wrbug.polymarketbot.api.PolymarketClobApi
 import com.wrbug.polymarketbot.api.PolymarketDataApi
 import com.wrbug.polymarketbot.api.PolymarketGammaApi
+import okhttp3.HttpUrl
+import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
 import okhttp3.Interceptor
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
 import okio.Buffer
+import java.util.concurrent.TimeUnit
 import org.slf4j.LoggerFactory
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.stereotype.Component
@@ -95,11 +102,32 @@ class RetrofitFactory(
     
     /**
      * 创建 Ethereum RPC API 客户端
+     * 使用固定的 baseUrl，通过拦截器动态替换为实际的 RPC URL
+     * 如果 RPC 不可用，将抛出异常
      * @param rpcUrl RPC 节点 URL
      * @return EthereumRpcApi 客户端
+     * @throws IllegalArgumentException 如果 RPC URL 无效或不可用
      */
     fun createEthereumRpcApi(rpcUrl: String): EthereumRpcApi {
-        val okHttpClient = createClient().build()
+        // 使用固定的 baseUrl（Retrofit 要求 baseUrl 必须以 / 结尾）
+        val fixedBaseUrl = "https://polyrpc.polyhermes/"
+        
+        // 确保实际的 RPC URL 以 / 结尾
+        val actualRpcUrl = if (rpcUrl.endsWith("/")) {
+            rpcUrl
+        } else {
+            "$rpcUrl/"
+        }
+        
+        // 验证 RPC 是否可用
+        validateRpcAvailability(actualRpcUrl)
+        
+        // 创建 URL 替换拦截器
+        val urlReplaceInterceptor = RpcUrlReplaceInterceptor(fixedBaseUrl, actualRpcUrl)
+        
+        val okHttpClient = createClient()
+            .addInterceptor(urlReplaceInterceptor)
+            .build()
         
         // 创建 lenient 模式的 Gson
         val gson = GsonBuilder()
@@ -107,13 +135,86 @@ class RetrofitFactory(
             .create()
         
         return Retrofit.Builder()
-            .baseUrl(rpcUrl)
+            .baseUrl(fixedBaseUrl)
             .client(okHttpClient)
             .addConverterFactory(GsonConverterFactory.create(gson))
             .build()
             .create(EthereumRpcApi::class.java)
     }
     
+    /**
+     * 验证 RPC 节点是否可用
+     * 通过发送一个简单的 eth_blockNumber 请求来验证
+     * @param rpcUrl RPC 节点 URL
+     * @throws IllegalArgumentException 如果 RPC 不可用
+     */
+    private fun validateRpcAvailability(rpcUrl: String) {
+        val logger = LoggerFactory.getLogger(RetrofitFactory::class.java)
+        
+        try {
+            // 解析 URL
+            val httpUrl = rpcUrl.toHttpUrlOrNull()
+                ?: throw IllegalArgumentException("无效的 RPC URL: $rpcUrl")
+            
+            // 创建 JSON-RPC 请求体
+            val jsonRpcRequest = """
+                {
+                    "jsonrpc": "2.0",
+                    "method": "eth_blockNumber",
+                    "params": [],
+                    "id": 1
+                }
+            """.trimIndent()
+            
+            val mediaType = "application/json; charset=utf-8".toMediaType()
+            val requestBody = jsonRpcRequest.toRequestBody(mediaType)
+            
+            // 创建请求
+            val request = Request.Builder()
+                .url(httpUrl)
+                .post(requestBody)
+                .header("Content-Type", "application/json")
+                .build()
+            
+            // 创建临时客户端用于验证（使用较短的超时时间）
+            val testClient = createClient()
+                .connectTimeout(5, TimeUnit.SECONDS)
+                .readTimeout(5, TimeUnit.SECONDS)
+                .writeTimeout(5, TimeUnit.SECONDS)
+                .build()
+            
+            // 发送请求
+            val response = testClient.newCall(request).execute()
+            
+            if (!response.isSuccessful) {
+                throw IllegalArgumentException("RPC 节点不可用: HTTP ${response.code} ${response.message}")
+            }
+            
+            val responseBody = response.body?.string()
+            if (responseBody.isNullOrBlank()) {
+                throw IllegalArgumentException("RPC 节点响应为空")
+            }
+            
+            // 检查响应是否包含错误
+            if (responseBody.contains("\"error\"")) {
+                throw IllegalArgumentException("RPC 节点返回错误: $responseBody")
+            }
+            
+            // 检查响应是否包含 result
+            if (!responseBody.contains("\"result\"")) {
+                throw IllegalArgumentException("RPC 节点响应格式错误: $responseBody")
+            }
+            
+            logger.debug("RPC 节点验证成功: $rpcUrl")
+        } catch (e: IllegalArgumentException) {
+            logger.error("RPC 节点验证失败: $rpcUrl - ${e.message}")
+            throw e
+        } catch (e: Exception) {
+            logger.error("RPC 节点验证失败: $rpcUrl - ${e.message}", e)
+            throw IllegalArgumentException("RPC 节点不可用: ${e.message}", e)
+        }
+    }
+    
     /**
      * 创建 Polymarket Gamma API 客户端
      * Gamma API 是公开 API，不需要认证
@@ -239,6 +340,39 @@ class RetrofitFactory(
     }
 }
 
+/**
+ * RPC URL 替换拦截器
+ * 用于将固定的 baseUrl 替换为实际的 RPC URL
+ */
+class RpcUrlReplaceInterceptor(
+    private val fixedBaseUrl: String,
+    private val actualRpcUrl: String
+) : Interceptor {
+    private val logger = LoggerFactory.getLogger(RpcUrlReplaceInterceptor::class.java)
+    
+    @Throws(IOException::class)
+    override fun intercept(chain: Interceptor.Chain): Response {
+        val originalRequest = chain.request()
+        val originalUrl = originalRequest.url
+        
+        // 将固定 baseUrl 替换为实际的 RPC URL
+        val originalUrlString = originalUrl.toString()
+        val newUrlString = originalUrlString.replace(fixedBaseUrl, actualRpcUrl)
+        
+        // 使用 HttpUrl 解析新 URL，确保格式正确
+        val newUrl = newUrlString.toHttpUrlOrNull()
+            ?: throw IllegalArgumentException("无效的 RPC URL: $newUrlString")
+        
+        logger.debug("RPC URL 替换: $originalUrlString -> $newUrlString")
+        
+        val newRequest = originalRequest.newBuilder()
+            .url(newUrl)
+            .build()
+        
+        return chain.proceed(newRequest)
+    }
+}
+
 /**
  * 响应日志拦截器
  * 用于记录 API 响应的原始内容，帮助调试 JSON 解析错误

backend/src/main/resources/db/migration/V12__create_rpc_node_config.sql

@@ -0,0 +1,41 @@
+-- 创建 RPC 节点配置表
+CREATE TABLE rpc_node_config (
+    id BIGINT AUTO_INCREMENT PRIMARY KEY COMMENT '主键',
+    provider_type VARCHAR(50) NOT NULL COMMENT '服务商类型: ALCHEMY, INFURA, QUICKNODE, CHAINSTACK, GETBLOCK, CUSTOM, PUBLIC',
+    name VARCHAR(100) NOT NULL COMMENT '节点名称',
+    http_url VARCHAR(500) NOT NULL COMMENT 'HTTP RPC URL',
+    ws_url VARCHAR(500) COMMENT 'WebSocket URL (可选)',
+    api_key VARCHAR(200) COMMENT 'API Key (加密存储)',
+    enabled BOOLEAN DEFAULT TRUE COMMENT '是否启用',
+    priority INT DEFAULT 0 COMMENT '优先级(数字越小优先级越高)',
+    last_check_time BIGINT COMMENT '最后检查时间(毫秒时间戳)',
+    last_check_status VARCHAR(20) COMMENT '最后检查状态: HEALTHY, UNHEALTHY, UNKNOWN',
+    response_time_ms INT COMMENT '最后一次响应时间(毫秒)',
+    created_at BIGINT NOT NULL COMMENT '创建时间(毫秒时间戳)',
+    updated_at BIGINT NOT NULL COMMENT '更新时间(毫秒时间戳)',
+    INDEX idx_enabled_priority (enabled, priority),
+    INDEX idx_last_check_status (last_check_status)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='Polygon RPC 节点配置表';
+
+-- 插入默认公共节点 (PublicNode)
+INSERT INTO rpc_node_config (
+    provider_type,
+    name,
+    http_url,
+    ws_url,
+    enabled,
+    priority,
+    created_at,
+    updated_at,
+    last_check_status
+) VALUES (
+    'PUBLIC',
+    'PublicNode (Default)',
+    'https://polygon.publicnode.com',
+    'wss://polygon.publicnode.com',
+    TRUE,
+    999,
+    UNIX_TIMESTAMP() * 1000,
+    UNIX_TIMESTAMP() * 1000,
+    'UNKNOWN'
+);