feat(blockchain): 1.0 blockchain-service 同步添加 RPC 端点自动故障转移

与 mining-blockchain-service (2.0) 保持一致的故障转移方案：
当 RPC 端点连续失败超过 3 分钟后自动轮转到下一个备选端点。

新增文件：
- rpc-provider-manager.service.ts: RPC 故障转移管理器（与 2.0 相同逻辑）

修改文件：
- blockchain.config.ts: 新增 rpcUrls 配置字段
- chain-config.service.ts: 新增 rpcUrls 属性和 parseRpcUrls 解析方法
- domain.module.ts: 注册并导出 RpcProviderManager
- index.ts: 导出 RpcProviderManager
- evm-provider.adapter.ts: 委托 RpcProviderManager 获取 provider，
  所有方法通过 executeWithFailover 包裹
- erc20-transfer.service.ts: 移除本地 providers Map，改用 RpcProviderManager，
  新增 isRpcConnectionError 区分 RPC 网络错误与合约执行错误
- docker-compose.yml: blockchain-service 添加 KAVA_RPC_URLS 默认 4 个端点

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/blockchain-service/src/config/blockchain.config.ts

@@ -30,6 +30,8 @@ export default registerAs('blockchain', () => {
       ? {
           // KAVA Testnet
           rpcUrl: process.env.KAVA_RPC_URL || 'https://evm.testnet.kava.io',
+          // 逗号分隔的多个 RPC URL，用于故障转移（可选，不配置则仅使用 rpcUrl）
+          rpcUrls: process.env.KAVA_RPC_URLS || '',
           chainId: parseInt(process.env.KAVA_CHAIN_ID || '2221', 10),
           // 测试网 USDT 合约 (自定义部署的 TestUSDT)
           usdtContract: process.env.KAVA_USDT_CONTRACT || '0xc12f6A4A7Fd0965085B044A67a39CcA2ff7fe0dF',
@@ -38,6 +40,8 @@ export default registerAs('blockchain', () => {
       : {
           // KAVA Mainnet
           rpcUrl: process.env.KAVA_RPC_URL || 'https://evm.kava.io',
+          // 逗号分隔的多个 RPC URL，用于故障转移（可选，不配置则仅使用 rpcUrl）
+          rpcUrls: process.env.KAVA_RPC_URLS || '',
           chainId: parseInt(process.env.KAVA_CHAIN_ID || '2222', 10),
           // dUSDT (绿积分) 合约地址 - Durian USDT, 精度6位
           usdtContract: process.env.KAVA_USDT_CONTRACT || '0xA9F3A35dBa8699c8C681D8db03F0c1A8CEB9D7c3',
@@ -49,6 +53,7 @@ export default registerAs('blockchain', () => {
       ? {
           // BSC Testnet (BNB Smart Chain Testnet)
           rpcUrl: process.env.BSC_RPC_URL || 'https://data-seed-prebsc-1-s1.binance.org:8545',
+          rpcUrls: process.env.BSC_RPC_URLS || '',
           chainId: parseInt(process.env.BSC_CHAIN_ID || '97', 10),
           // BSC Testnet 官方测试 USDT 合约
           usdtContract: process.env.BSC_USDT_CONTRACT || '0x337610d27c682E347C9cD60BD4b3b107C9d34dDd',
@@ -57,6 +62,7 @@ export default registerAs('blockchain', () => {
       : {
           // BSC Mainnet
           rpcUrl: process.env.BSC_RPC_URL || 'https://bsc-dataseed.binance.org',
+          rpcUrls: process.env.BSC_RPC_URLS || '',
           chainId: parseInt(process.env.BSC_CHAIN_ID || '56', 10),
           usdtContract: process.env.BSC_USDT_CONTRACT || '0x55d398326f99059fF775485246999027B3197955',
           confirmations: parseInt(process.env.BSC_CONFIRMATIONS || '15', 10),

backend/services/blockchain-service/src/domain/domain.module.ts

@@ -1,9 +1,9 @@
 import { Module } from '@nestjs/common';
-import { ConfirmationPolicyService, ChainConfigService } from './services';
+import { ConfirmationPolicyService, ChainConfigService, RpcProviderManager } from './services';
 import { Erc20TransferService } from './services/erc20-transfer.service';
 
 @Module({
-  providers: [ConfirmationPolicyService, ChainConfigService, Erc20TransferService],
-  exports: [ConfirmationPolicyService, ChainConfigService, Erc20TransferService],
+  providers: [ConfirmationPolicyService, ChainConfigService, RpcProviderManager, Erc20TransferService],
+  exports: [ConfirmationPolicyService, ChainConfigService, RpcProviderManager, Erc20TransferService],
 })
 export class DomainModule {}

backend/services/blockchain-service/src/domain/services/chain-config.service.ts

@@ -7,6 +7,8 @@ export interface ChainConfig {
   chainType: ChainTypeEnum;
   chainId: number;
   rpcUrl: string;
+  /** RPC URL 列表（含主端点和备选端点），用于故障转移 */
+  rpcUrls: string[];
   usdtContract: string;
   nativeSymbol: string;
   blockTime: number; // 平均出块时间（秒）
@@ -42,6 +44,13 @@ export class ChainConfigService {
         'blockchain.kava.rpcUrl',
         this.isTestnet ? 'https://evm.testnet.kava.io' : 'https://evm.kava.io',
       ),
+      rpcUrls: this.parseRpcUrls(
+        'blockchain.kava.rpcUrls',
+        this.configService.get<string>(
+          'blockchain.kava.rpcUrl',
+          this.isTestnet ? 'https://evm.testnet.kava.io' : 'https://evm.kava.io',
+        ),
+      ),
       // dUSDT (绿积分) 合约地址 - Durian USDT, 精度6位
       usdtContract: this.configService.get<string>(
         'blockchain.kava.usdtContract',
@@ -61,6 +70,13 @@ export class ChainConfigService {
         'blockchain.bsc.rpcUrl',
         this.isTestnet ? 'https://data-seed-prebsc-1-s1.binance.org:8545' : 'https://bsc-dataseed.binance.org',
       ),
+      rpcUrls: this.parseRpcUrls(
+        'blockchain.bsc.rpcUrls',
+        this.configService.get<string>(
+          'blockchain.bsc.rpcUrl',
+          this.isTestnet ? 'https://data-seed-prebsc-1-s1.binance.org:8545' : 'https://bsc-dataseed.binance.org',
+        ),
+      ),
       usdtContract: this.configService.get<string>(
         'blockchain.bsc.usdtContract',
         this.isTestnet ? '0x337610d27c682E347C9cD60BD4b3b107C9d34dDd' : '0x55d398326f99059fF775485246999027B3197955',
@@ -114,4 +130,24 @@ export class ChainConfigService {
   isSupported(chainType: ChainType): boolean {
     return this.configs.has(chainType.value);
   }
+
+  /**
+   * 解析 RPC URL 列表
+   *
+   * 如果配置了逗号分隔的多 URL（如 KAVA_RPC_URLS），使用它作为完整列表；
+   * 否则回退到单个 rpcUrl，行为与之前完全一致。
+   */
+  private parseRpcUrls(configKey: string, fallbackUrl: string): string[] {
+    const urlsStr = this.configService.get<string>(configKey, '');
+    if (urlsStr) {
+      const urls = urlsStr
+        .split(',')
+        .map((u) => u.trim())
+        .filter((u) => u.length > 0);
+      if (urls.length > 0) {
+        return urls;
+      }
+    }
+    return [fallbackUrl];
+  }
 }

backend/services/blockchain-service/src/domain/services/erc20-transfer.service.ts

@@ -10,6 +10,7 @@ import {
   recoverAddress,
 } from 'ethers';
 import { ChainConfigService } from './chain-config.service';
+import { RpcProviderManager } from './rpc-provider-manager.service';
 import { ChainType } from '@/domain/value-objects';
 import { ChainTypeEnum } from '@/domain/enums';
 
@@ -47,16 +48,16 @@ export const MPC_SIGNING_CLIENT = Symbol('MPC_SIGNING_CLIENT');
 @Injectable()
 export class Erc20TransferService {
   private readonly logger = new Logger(Erc20TransferService.name);
-  private readonly providers: Map<ChainTypeEnum, JsonRpcProvider> = new Map();
   private readonly hotWalletAddress: string;
   private mpcSigningClient: IMpcSigningClient | null = null;
 
   constructor(
     private readonly configService: ConfigService,
     private readonly chainConfig: ChainConfigService,
+    private readonly rpcProviderManager: RpcProviderManager,
   ) {
     this.hotWalletAddress = this.configService.get<string>('HOT_WALLET_ADDRESS', '');
-    this.initializeProviders();
+    this.initializeWalletConfig();
   }
 
   /**
@@ -67,19 +68,40 @@ export class Erc20TransferService {
     this.logger.log(`[INIT] MPC Signing Client injected`);
   }
 
-  private initializeProviders(): void {
-    // 为每条支持的链创建 Provider
-    for (const chainType of this.chainConfig.getSupportedChains()) {
-      try {
-        const config = this.chainConfig.getConfig(ChainType.fromEnum(chainType));
-        const provider = new JsonRpcProvider(config.rpcUrl, config.chainId);
-        this.providers.set(chainType, provider);
-        this.logger.log(`[INIT] Provider initialized for ${chainType}: ${config.rpcUrl}`);
-      } catch (error) {
-        this.logger.error(`[INIT] Failed to initialize provider for ${chainType}`, error);
-      }
-    }
+  /**
+   * 获取某条链当前活跃的 provider（由 RpcProviderManager 统一管理，支持故障转移）
+   */
+  private getProvider(chainType: ChainTypeEnum): JsonRpcProvider {
+    return this.rpcProviderManager.getProvider(chainType);
+  }
 
+  /**
+   * 判断错误是否为 RPC 连接类错误（需要触发故障转移）
+   * 区分 RPC 网络错误（503、超时等）和合约执行错误（revert、余额不足等）
+   */
+  private isRpcConnectionError(error: any): boolean {
+    const message = (error?.message || '').toLowerCase();
+    return (
+      message.includes('could not detect network') ||
+      message.includes('connection refused') ||
+      message.includes('timeout') ||
+      message.includes('econnrefused') ||
+      message.includes('enotfound') ||
+      message.includes('503') ||
+      message.includes('502') ||
+      message.includes('server error') ||
+      message.includes('missing response') ||
+      message.includes('request failed') ||
+      error?.code === 'NETWORK_ERROR' ||
+      error?.code === 'SERVER_ERROR' ||
+      error?.code === 'TIMEOUT'
+    );
+  }
+
+  /**
+   * 初始化钱包配置检查（provider 由 RpcProviderManager 统一管理）
+   */
+  private initializeWalletConfig(): void {
     // 检查热钱包地址配置
     if (this.hotWalletAddress) {
       this.logger.log(`[INIT] Hot wallet address configured: ${this.hotWalletAddress}`);
@@ -100,10 +122,7 @@ export class Erc20TransferService {
    * 获取热钱包 USDT 余额
    */
   async getHotWalletBalance(chainType: ChainTypeEnum): Promise<string> {
-    const provider = this.providers.get(chainType);
-    if (!provider) {
-      throw new Error(`Provider not configured for chain: ${chainType}`);
-    }
+    const provider = this.getProvider(chainType);
 
     if (!this.hotWalletAddress) {
       throw new Error('Hot wallet address not configured');
@@ -136,12 +155,7 @@ export class Erc20TransferService {
     this.logger.log(`[TRANSFER] To: ${toAddress}`);
     this.logger.log(`[TRANSFER] Amount: ${amount} USDT`);
 
-    const provider = this.providers.get(chainType);
-    if (!provider) {
-      const error = `Provider not configured for chain: ${chainType}`;
-      this.logger.error(`[TRANSFER] ${error}`);
-      return { success: false, error };
-    }
+    const provider = this.getProvider(chainType);
 
     if (!this.mpcSigningClient || !this.mpcSigningClient.isConfigured()) {
       const error = 'MPC signing client not configured';
@@ -296,6 +310,7 @@ export class Erc20TransferService {
         this.logger.log(`[TRANSFER] Block: ${receipt.blockNumber}`);
         this.logger.log(`[TRANSFER] Gas used: ${receipt.gasUsed.toString()}`);
 
+        this.rpcProviderManager.reportSuccess(chainType);
         return {
           success: true,
           txHash: txResponse.hash,
@@ -308,6 +323,9 @@ export class Erc20TransferService {
         return { success: false, txHash: txResponse.hash, error };
       }
     } catch (error: any) {
+      if (this.isRpcConnectionError(error)) {
+        this.rpcProviderManager.reportFailure(chainType, error);
+      }
       this.logger.error(`[TRANSFER] Transfer failed:`, error);
       return {
         success: false,
@@ -320,8 +338,11 @@ export class Erc20TransferService {
    * 检查热钱包是否已配置
    */
   isConfigured(chainType: ChainTypeEnum): boolean {
-    return this.providers.has(chainType) &&
-           !!this.hotWalletAddress &&
-           !!this.mpcSigningClient?.isConfigured();
+    try {
+      this.rpcProviderManager.getProvider(chainType);
+      return !!this.hotWalletAddress && !!this.mpcSigningClient?.isConfigured();
+    } catch {
+      return false;
+    }
   }
 }

backend/services/blockchain-service/src/domain/services/index.ts

@@ -1,2 +1,3 @@
 export * from './confirmation-policy.service';
 export * from './chain-config.service';
+export * from './rpc-provider-manager.service';

backend/services/blockchain-service/src/domain/services/rpc-provider-manager.service.ts

@@ -0,0 +1,212 @@
+import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
+import { JsonRpcProvider } from 'ethers';
+import { ChainConfigService } from './chain-config.service';
+import { ChainTypeEnum } from '@/domain/enums';
+
+/**
+ * 每条链的 RPC 端点健康状态
+ */
+interface RpcHealthState {
+  /** 当前活跃的 JsonRpcProvider 实例 */
+  provider: JsonRpcProvider;
+  /** 该链可用的所有 RPC URL 列表（第一个为默认主端点） */
+  urls: string[];
+  /** 当前使用的 URL 在 urls 数组中的索引 */
+  currentIndex: number;
+  /** 该链的 chainId（用于创建新 provider） */
+  chainId: number;
+  /** 首次连续失败的时间戳（null 表示当前健康） */
+  firstFailureAt: number | null;
+  /** 连续失败次数（用于日志） */
+  consecutiveFailures: number;
+}
+
+/**
+ * RPC Provider 管理器 — 自动故障转移
+ *
+ * 集中管理各链的 JsonRpcProvider 实例。当某条链的 RPC 端点
+ * 持续失败超过 FAILOVER_THRESHOLD_MS（默认 3 分钟）时，
+ * 自动切换到下一个备选端点。
+ *
+ * 使用方式:
+ *   - EvmProviderAdapter 和 Erc20TransferService 通过此服务获取 provider
+ *   - RPC 调用成功后调用 reportSuccess(chain) 重置失败状态
+ *   - RPC 调用失败后调用 reportFailure(chain, error) 记录失败
+ *   - 超过阈值后自动轮转到下一个 URL
+ *
+ * 环境变量:
+ *   - KAVA_RPC_URLS: 逗号分隔的多个 Kava RPC URL（可选，默认使用 KAVA_RPC_URL）
+ *   - BSC_RPC_URLS:  逗号分隔的多个 BSC RPC URL（可选，默认使用 BSC_RPC_URL）
+ */
+@Injectable()
+export class RpcProviderManager implements OnModuleInit {
+  private readonly logger = new Logger(RpcProviderManager.name);
+  private readonly healthStates: Map<ChainTypeEnum, RpcHealthState> = new Map();
+
+  /** 持续失败多久后触发端点切换（毫秒），默认 3 分钟 */
+  private readonly FAILOVER_THRESHOLD_MS = 3 * 60 * 1000;
+
+  constructor(private readonly chainConfig: ChainConfigService) {}
+
+  onModuleInit(): void {
+    this.initializeAllChains();
+  }
+
+  /**
+   * 初始化所有支持链的 provider
+   * 从 ChainConfig 中读取 rpcUrls 列表，创建初始 provider
+   */
+  private initializeAllChains(): void {
+    for (const chainType of this.chainConfig.getSupportedChains()) {
+      const config = this.chainConfig.getConfig(
+        { value: chainType, toString: () => chainType } as any,
+      );
+
+      const urls = config.rpcUrls;
+      const primaryUrl = urls[0];
+      const provider = new JsonRpcProvider(primaryUrl, config.chainId);
+
+      this.healthStates.set(chainType, {
+        provider,
+        urls,
+        currentIndex: 0,
+        chainId: config.chainId,
+        firstFailureAt: null,
+        consecutiveFailures: 0,
+      });
+
+      if (urls.length > 1) {
+        this.logger.log(
+          `[INIT] ${chainType} RPC 端点列表 (${urls.length} 个): ${urls.join(', ')}`,
+        );
+      } else {
+        this.logger.log(
+          `[INIT] ${chainType} RPC 端点: ${primaryUrl}（未配置备选端点）`,
+        );
+      }
+    }
+  }
+
+  /**
+   * 获取某条链当前活跃的 provider
+   *
+   * @param chain 链类型枚举
+   * @returns 当前活跃的 JsonRpcProvider
+   * @throws Error 如果该链未初始化
+   */
+  getProvider(chain: ChainTypeEnum): JsonRpcProvider {
+    const state = this.healthStates.get(chain);
+    if (!state) {
+      throw new Error(`RPC Provider 未初始化: ${chain}`);
+    }
+    return state.provider;
+  }
+
+  /**
+   * 获取某条链当前使用的 RPC URL（用于日志/调试）
+   */
+  getCurrentUrl(chain: ChainTypeEnum): string {
+    const state = this.healthStates.get(chain);
+    return state ? state.urls[state.currentIndex] : 'unknown';
+  }
+
+  /**
+   * 获取某条链的所有可用 RPC URL 数量
+   */
+  getUrlCount(chain: ChainTypeEnum): number {
+    const state = this.healthStates.get(chain);
+    return state ? state.urls.length : 0;
+  }
+
+  /**
+   * 报告 RPC 调用成功
+   * 重置该链的失败计时和连续失败次数
+   */
+  reportSuccess(chain: ChainTypeEnum): void {
+    const state = this.healthStates.get(chain);
+    if (!state) return;
+
+    // 如果之前处于失败状态，记录恢复日志
+    if (state.firstFailureAt !== null) {
+      this.logger.log(
+        `[${chain}] RPC 恢复正常: ${state.urls[state.currentIndex]}` +
+          ` (之前连续失败 ${state.consecutiveFailures} 次)`,
+      );
+    }
+    state.firstFailureAt = null;
+    state.consecutiveFailures = 0;
+  }
+
+  /**
+   * 报告 RPC 调用失败
+   *
+   * 首次失败时记录时间戳。后续持续失败超过 FAILOVER_THRESHOLD_MS 后，
+   * 自动切换到下一个备选端点。
+   *
+   * @param chain 链类型枚举
+   * @param error 可选的错误对象（用于日志）
+   */
+  reportFailure(chain: ChainTypeEnum, error?: Error): void {
+    const state = this.healthStates.get(chain);
+    if (!state) return;
+
+    const now = Date.now();
+    state.consecutiveFailures++;
+
+    // 首次失败：记录起始时间
+    if (state.firstFailureAt === null) {
+      state.firstFailureAt = now;
+      this.logger.warn(
+        `[${chain}] RPC 开始失败: ${state.urls[state.currentIndex]}` +
+          ` — ${error?.message || 'unknown error'}`,
+      );
+      return;
+    }
+
+    // 检查是否超过故障转移阈值
+    const elapsedMs = now - state.firstFailureAt;
+    if (elapsedMs >= this.FAILOVER_THRESHOLD_MS) {
+      this.switchToNextUrl(chain, state);
+    } else {
+      // 每 30 秒输出一条持续失败日志，避免日志洪水
+      if (state.consecutiveFailures % 6 === 0) {
+        this.logger.warn(
+          `[${chain}] RPC 持续失败中 (${Math.round(elapsedMs / 1000)}s / ` +
+            `${this.FAILOVER_THRESHOLD_MS / 1000}s): ` +
+            `${state.urls[state.currentIndex]}`,
+        );
+      }
+    }
+  }
+
+  /**
+   * 切换到下一个 RPC URL
+   *
+   * 轮转到 urls 列表中的下一个端点，创建新的 JsonRpcProvider 实例。
+   * 如果只有一个 URL，则重新创建 provider（处理临时网络问题）。
+   */
+  private switchToNextUrl(chain: ChainTypeEnum, state: RpcHealthState): void {
+    const oldUrl = state.urls[state.currentIndex];
+
+    // 轮转到下一个 URL
+    state.currentIndex = (state.currentIndex + 1) % state.urls.length;
+    const newUrl = state.urls[state.currentIndex];
+
+    if (state.urls.length === 1) {
+      this.logger.error(
+        `[${chain}] 仅有一个 RPC URL，无法切换到备选端点，将重新创建 provider: ${newUrl}`,
+      );
+    } else {
+      this.logger.warn(
+        `[${chain}] === RPC 端点切换 === ${oldUrl} → ${newUrl}`,
+      );
+    }
+
+    // 创建新的 provider 实例（ethers.js v6 的 JsonRpcProvider 创建后 URL 不可变）
+    state.provider = new JsonRpcProvider(newUrl, state.chainId);
+
+    // 重置失败状态，给新端点一个全新的 3 分钟窗口
+    state.firstFailureAt = null;
+    state.consecutiveFailures = 0;
+  }
+}

backend/services/blockchain-service/src/infrastructure/blockchain/evm-provider.adapter.ts

@@ -1,6 +1,6 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { JsonRpcProvider, Contract } from 'ethers';
-import { ChainConfigService } from '@/domain/services/chain-config.service';
+import { RpcProviderManager } from '@/domain/services/rpc-provider-manager.service';
 import { ChainType, BlockNumber, TokenAmount } from '@/domain/value-objects';
 import { ChainTypeEnum } from '@/domain/enums';
 
@@ -28,53 +28,71 @@ export interface TransferEvent {
 
 /**
  * EVM 区块链提供者适配器
- * 封装与 EVM 链的交互
+ *
+ * 封装与 EVM 链的交互。通过 RpcProviderManager 获取 provider，
+ * 自动上报 RPC 调用的成功/失败状态，实现故障转移。
  */
 @Injectable()
 export class EvmProviderAdapter {
   private readonly logger = new Logger(EvmProviderAdapter.name);
-  private readonly providers: Map<ChainTypeEnum, JsonRpcProvider> = new Map();
 
-  constructor(private readonly chainConfig: ChainConfigService) {
-    this.initializeProviders();
-  }
-
-  private initializeProviders(): void {
-    for (const chainType of this.chainConfig.getSupportedChains()) {
-      const config = this.chainConfig.getConfig(ChainType.fromEnum(chainType));
-      const provider = new JsonRpcProvider(config.rpcUrl, config.chainId);
-      this.providers.set(chainType, provider);
-      this.logger.log(`Initialized provider for ${chainType}: ${config.rpcUrl}`);
-    }
-  }
+  constructor(private readonly rpcProviderManager: RpcProviderManager) {}
 
+  /**
+   * 获取某条链当前活跃的 provider（由 RpcProviderManager 统一管理）
+   */
   private getProvider(chainType: ChainType): JsonRpcProvider {
-    const provider = this.providers.get(chainType.value);
-    if (!provider) {
-      throw new Error(`No provider for chain: ${chainType.toString()}`);
+    return this.rpcProviderManager.getProvider(chainType.value);
+  }
+
+  /**
+   * 执行 RPC 调用并自动上报成功/失败状态
+   *
+   * 所有公开方法通过此辅助方法包裹 RPC 调用：
+   * - 成功时调用 reportSuccess() 重置失败计时
+   * - 失败时调用 reportFailure() 记录失败（超过 3 分钟自动切换端点）
+   * - 错误会 re-throw，不影响调用方的错误处理逻辑
+   */
+  private async executeWithFailover<T>(
+    chainType: ChainType,
+    operation: () => Promise<T>,
+  ): Promise<T> {
+    try {
+      const result = await operation();
+      this.rpcProviderManager.reportSuccess(chainType.value);
+      return result;
+    } catch (error) {
+      this.rpcProviderManager.reportFailure(
+        chainType.value,
+        error instanceof Error ? error : new Error(String(error)),
+      );
+      throw error;
     }
-    return provider;
   }
 
   /**
    * 获取当前区块号
    */
   async getCurrentBlockNumber(chainType: ChainType): Promise<BlockNumber> {
-    const provider = this.getProvider(chainType);
-    const blockNumber = await provider.getBlockNumber();
-    return BlockNumber.create(blockNumber);
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const blockNumber = await provider.getBlockNumber();
+      return BlockNumber.create(blockNumber);
+    });
   }
 
   /**
    * 获取区块时间戳
    */
   async getBlockTimestamp(chainType: ChainType, blockNumber: BlockNumber): Promise<Date> {
-    const provider = this.getProvider(chainType);
-    const block = await provider.getBlock(blockNumber.asNumber);
-    if (!block) {
-      throw new Error(`Block not found: ${blockNumber.toString()}`);
-    }
-    return new Date(block.timestamp * 1000);
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const block = await provider.getBlock(blockNumber.asNumber);
+      if (!block) {
+        throw new Error(`Block not found: ${blockNumber.toString()}`);
+      }
+      return new Date(block.timestamp * 1000);
+    });
   }
 
   /**
@@ -86,38 +104,40 @@ export class EvmProviderAdapter {
     toBlock: BlockNumber,
     tokenContract: string,
   ): Promise<TransferEvent[]> {
-    const provider = this.getProvider(chainType);
-    const contract = new Contract(tokenContract, ERC20_TRANSFER_EVENT_ABI, provider);
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const contract = new Contract(tokenContract, ERC20_TRANSFER_EVENT_ABI, provider);
 
-    const filter = contract.filters.Transfer();
-    const logs = await contract.queryFilter(filter, fromBlock.asNumber, toBlock.asNumber);
+      const filter = contract.filters.Transfer();
+      const logs = await contract.queryFilter(filter, fromBlock.asNumber, toBlock.asNumber);
 
-    const events: TransferEvent[] = [];
+      const events: TransferEvent[] = [];
 
-    for (const log of logs) {
-      const block = await provider.getBlock(log.blockNumber);
-      if (!block) continue;
+      for (const log of logs) {
+        const block = await provider.getBlock(log.blockNumber);
+        if (!block) continue;
 
-      const parsedLog = contract.interface.parseLog({
-        topics: log.topics as string[],
-        data: log.data,
-      });
-
-      if (parsedLog) {
-        events.push({
-          txHash: log.transactionHash,
-          logIndex: log.index,
-          blockNumber: BigInt(log.blockNumber),
-          blockTimestamp: new Date(block.timestamp * 1000),
-          from: parsedLog.args[0],
-          to: parsedLog.args[1],
-          value: parsedLog.args[2],
-          tokenContract,
+        const parsedLog = contract.interface.parseLog({
+          topics: log.topics as string[],
+          data: log.data,
         });
-      }
-    }
 
-    return events;
+        if (parsedLog) {
+          events.push({
+            txHash: log.transactionHash,
+            logIndex: log.index,
+            blockNumber: BigInt(log.blockNumber),
+            blockTimestamp: new Date(block.timestamp * 1000),
+            from: parsedLog.args[0],
+            to: parsedLog.args[1],
+            value: parsedLog.args[2],
+            tokenContract,
+          });
+        }
+      }
+
+      return events;
+    });
   }
 
   /**
@@ -128,42 +148,50 @@ export class EvmProviderAdapter {
     tokenContract: string,
     address: string,
   ): Promise<TokenAmount> {
-    const provider = this.getProvider(chainType);
-    const contract = new Contract(tokenContract, ERC20_BALANCE_ABI, provider);
-    const [balance, decimals] = await Promise.all([
-      contract.balanceOf(address),
-      contract.decimals(),
-    ]);
-    return TokenAmount.fromRaw(balance, Number(decimals));
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const contract = new Contract(tokenContract, ERC20_BALANCE_ABI, provider);
+      const [balance, decimals] = await Promise.all([
+        contract.balanceOf(address),
+        contract.decimals(),
+      ]);
+      return TokenAmount.fromRaw(balance, Number(decimals));
+    });
   }
 
   /**
    * 查询 ERC20 代币的 decimals
    */
   async getTokenDecimals(chainType: ChainType, tokenContract: string): Promise<number> {
-    const provider = this.getProvider(chainType);
-    const contract = new Contract(tokenContract, ERC20_BALANCE_ABI, provider);
-    const decimals = await contract.decimals();
-    return Number(decimals);
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const contract = new Contract(tokenContract, ERC20_BALANCE_ABI, provider);
+      const decimals = await contract.decimals();
+      return Number(decimals);
+    });
   }
 
   /**
    * 查询原生代币余额
    */
   async getNativeBalance(chainType: ChainType, address: string): Promise<TokenAmount> {
-    const provider = this.getProvider(chainType);
-    const balance = await provider.getBalance(address);
-    return TokenAmount.fromRaw(balance, 18);
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const balance = await provider.getBalance(address);
+      return TokenAmount.fromRaw(balance, 18);
+    });
   }
 
   /**
    * 广播签名交易
    */
   async broadcastTransaction(chainType: ChainType, signedTx: string): Promise<string> {
-    const provider = this.getProvider(chainType);
-    const txResponse = await provider.broadcastTransaction(signedTx);
-    this.logger.log(`Transaction broadcasted: ${txResponse.hash}`);
-    return txResponse.hash;
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const txResponse = await provider.broadcastTransaction(signedTx);
+      this.logger.log(`Transaction broadcasted: ${txResponse.hash}`);
+      return txResponse.hash;
+    });
   }
 
   /**
@@ -174,9 +202,11 @@ export class EvmProviderAdapter {
     txHash: string,
     confirmations: number = 1,
   ): Promise<boolean> {
-    const provider = this.getProvider(chainType);
-    const receipt = await provider.waitForTransaction(txHash, confirmations);
-    return receipt !== null && receipt.status === 1;
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const receipt = await provider.waitForTransaction(txHash, confirmations);
+      return receipt !== null && receipt.status === 1;
+    });
   }
 
   /**
@@ -187,12 +217,14 @@ export class EvmProviderAdapter {
     txHash: string,
     requiredConfirmations: number,
   ): Promise<boolean> {
-    const provider = this.getProvider(chainType);
-    const receipt = await provider.getTransactionReceipt(txHash);
-    if (!receipt) return false;
+    return this.executeWithFailover(chainType, async () => {
+      const provider = this.getProvider(chainType);
+      const receipt = await provider.getTransactionReceipt(txHash);
+      if (!receipt) return false;
 
-    const currentBlock = await provider.getBlockNumber();
-    const confirmations = currentBlock - receipt.blockNumber;
-    return confirmations >= requiredConfirmations;
+      const currentBlock = await provider.getBlockNumber();
+      const confirmations = currentBlock - receipt.blockNumber;
+      return confirmations >= requiredConfirmations;
+    });
   }
 }

backend/services/docker-compose.yml

@@ -736,6 +736,8 @@ services:
       - NETWORK_MODE=mainnet
       # 主网配置 - dUSDT (绿积分) 合约
       - KAVA_RPC_URL=https://evm.kava.io
+      # RPC 故障转移：逗号分隔的多个端点，主端点失败 3 分钟后自动切换
+      - KAVA_RPC_URLS=${KAVA_RPC_URLS:-https://evm.kava.io,https://evm.kava-rpc.com,https://kava-evm-rpc.publicnode.com,https://rpc.ankr.com/kava_evm}
       - KAVA_CHAIN_ID=2222
       - KAVA_USDT_CONTRACT=0xA9F3A35dBa8699c8C681D8db03F0c1A8CEB9D7c3
       # BSC 主网 (暂未使用)