submit_gasless_swap

Execute cryptocurrency swaps without paying gas fees by signing approval and trade messages. This tool processes gasless transactions using pre-approved quote data.

Instructions

Submit a gasless swap by signing approval and trade messages (no gas fees required)

Input Schema

TableJSON Schema

Name	Required	Description	Default
`quoteData`	Yes	Quote data from get_gasless_quote
`chainId`	No	Blockchain ID (optional if included in quoteData)

Implementation Reference

src/toolService.js:471-543 (handler)

Main handler for submit_gasless_swap tool: validates input, signs approval/trade EIP-712 messages using user private key, calls agService.submitGaslessSwap to submit to relayer API.

async submitGaslessSwap(params) {
  const { quoteData } = params;

  if (!quoteData) {
    throw new Error("Quote data from gasless quote is required");
  }

  if (!this.userPrivateKey) {
    throw new Error(
      "User private key is required for gasless swap execution"
    );
  }

  try {
    console.log("🚀 Processing gasless swap...");

    // Prepare the submission data - extract chainId from trade domain
    const chainId =
      quoteData.trade?.eip712?.domain?.chainId || params.chainId;
    if (!chainId) {
      throw new Error("Chain ID not found in quote data or parameters");
    }

    const submissionData = {
      chainId: chainId,
    };

    // Sign approval if present
    if (quoteData.approval) {
      console.log("🔐 Signing gasless approval...");
      const signedApproval = await this.blockchain.signGaslessApproval(
        quoteData.approval
      );
      submissionData.approval = signedApproval;
      console.log("✅ Approval signed");
    }

    // Sign trade (always required)
    if (!quoteData.trade) {
      throw new Error("Trade data is required in gasless quote");
    }

    console.log("🔐 Signing gasless trade...");
    const signedTrade = await this.blockchain.signGaslessTrade(
      quoteData.trade
    );
    submissionData.trade = signedTrade;
    console.log("✅ Trade signed");

    // Submit to Aggregator gasless API
    console.log("📤 Submitting gasless swap to Agg...");
    const result = await this.agg.submitGaslessSwap(submissionData);

    return {
      message: "Gasless swap submitted successfully",
      data: result,
      nextSteps: [
        "1. Gasless swap has been submitted to relayer",
        "2. Monitor status using get_gasless_status tool",
        "3. No gas fees required - relayer handles execution",
        `4. Trade hash: ${result.tradeHash}`,
      ],
      gaslessInfo: {
        tradeHash: result.tradeHash,
        approvalSigned: !!submissionData.approval,
        tradeSigned: !!submissionData.trade,
        relayerHandled: true,
      },
    };
  } catch (error) {
    throw new Error(`Gasless swap submission failed: ${error.message}`);
  }
}

src/index.js:706-724 (schema)

Input schema definition for the submit_gasless_swap tool, specifying required quoteData object and optional chainId.

{
  name: TOOL_NAMES.SUBMIT_GASLESS_SWAP,
  description:
    "Submit a gasless swap by signing approval and trade messages (no gas fees required)",
  inputSchema: {
    type: "object",
    properties: {
      quoteData: {
        type: "object",
        description: "Quote data from get_gasless_quote",
      },
      chainId: {
        type: "integer",
        description: "Blockchain ID (optional if included in quoteData)",
      },
    },
    required: ["quoteData"],
  },
},

src/index.js:1146-1147 (registration)
Tool dispatch/registration in MCP server request handler: maps tool name to toolService.submitGaslessSwap execution.
```
case TOOL_NAMES.SUBMIT_GASLESS_SWAP:
  result = await toolService.submitGaslessSwap(args);
```

src/services/agService.js:160-184 (helper)

agService helper method: HTTP POST to aggregator API /api/swap/gasless/submit with signed swap data, handles response and errors.

async submitGaslessSwap(swapData) {
  try {
    const response = await fetch(`${this.baseUrl}/api/swap/gasless/submit`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(swapData)
    });
    
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}: ${response.statusText}`);
    }
    
    const data = await response.json();
    
    if (!data.success) {
      throw new Error(data.error || 'Gasless swap submission failed');
    }
    
    return data.data;
  } catch (error) {
    throw new Error(`Failed to submit gasless swap: ${error.message}`);
  }
}

src/constants.js:13-13 (registration)
TOOL_NAMES constant mapping tool key to string name 'submit_gasless_swap' used in registration.
```
SUBMIT_GASLESS_SWAP: "submit_gasless_swap",
```

DeFi Trading Agent MCP Server