ValueRouter MCP Server

Instructions

Implementation Reference

• src/index.ts:460-476 (handler)

  Primary MCP tool handler for 'estimate_bridge_fees' that extracts arguments and delegates to QuoteService.estimateFees, handles errors and formats response.

  private async estimateBridgeFees(args: any): Promise<MCPToolResult> {
    try {
      const { fromChainId, toChainId, amount, tokenAddress } = args;
      const result = await this.quoteService.estimateFees(
        fromChainId,
        toChainId,
        amount,
        tokenAddress
      );
      return createSuccessResponse(result);
    } catch (error) {
      return createErrorResponse(
        error instanceof Error ? error.message : String(error),
        'FEE_ESTIMATION_ERROR'
      );
    }
  }

• src/index.ts:291-323 (registration)

  Tool registration in ListTools handler, including name, description, and input schema.

  {
    name: 'estimate_bridge_fees',
    description: 'Estimate fees for a bridge transaction',
    inputSchema: {
      type: 'object',
      properties: {
        fromChainId: {
          oneOf: [
            { type: 'number' },
            { type: 'string' },
          ],
          description: 'Source chain ID',
        },
        toChainId: {
          oneOf: [
            { type: 'number' },
            { type: 'string' },
          ],
          description: 'Destination chain ID',
        },
        amount: {
          type: 'string',
          description: 'Amount to bridge',
        },
        tokenAddress: {
          type: 'string',
          description: 'Token address (optional, defaults to USDC)',
        },
      },
      required: ['fromChainId', 'toChainId', 'amount'],
      additionalProperties: false,
    },
  },

• src/services/quote.ts:107-125 (handler)

  Core fee estimation logic called by the tool handler, computes bridge fee and gas fee, returns structured result.

  async estimateFees(
    fromChainId: SupportedChainId,
    toChainId: SupportedChainId,
    amount: string,
    tokenAddress?: string
  ): Promise<{
    bridgeFee: string;
    gasFee: string;
    totalFee: string;
  }> {
    const bridgeFee = this.calculateBridgeFee(amount);
    const gasFee = await this.estimateGasFees(fromChainId, toChainId);
    
    return {
      bridgeFee,
      gasFee,
      totalFee: (BigInt(bridgeFee) + BigInt(gasFee)).toString(),
    };
  }

• src/services/quote.ts:190-193 (helper)

  Helper function to calculate the bridge fee based on amount and FEE_CONFIG.BRIDGE_FEE_BPS.

  private calculateBridgeFee(amount: string): string {
    const bridgeFeeAmount = (BigInt(amount) * BigInt(FEE_CONFIG.BRIDGE_FEE_BPS)) / BigInt(10000);
    return bridgeFeeAmount.toString();
  }

• src/services/quote.ts:195-207 (helper)

  Helper function to estimate gas fees based on source chain type with hardcoded values.

  private async estimateGasFees(fromChainId: SupportedChainId, toChainId: SupportedChainId): Promise<string> {
    if (isEVMChain(fromChainId)) {
      return ethers.utils.parseEther('0.01').toString(); // ~$20-30 on mainnet
    } else if (isSolanaChain(fromChainId)) {
      return '5000'; // ~0.000005 SOL
    } else if (isSuiChain(fromChainId)) {
      return '1000000'; // ~0.001 SUI
    } else if (isCosmosChain(fromChainId)) {
      return '5000'; // varies by chain
    }
  
    return '0';
  }