get_gasless_approval_tokens

Retrieve tokens supporting gasless approvals via EIP-2612 permit to reduce transaction costs and streamline DeFi interactions on supported blockchains.

Instructions

Get list of tokens that support gasless approvals (EIP-2612 permit)

Input Schema

TableJSON Schema

Name	Required	Description	Default
`chainId`	No	Blockchain ID (e.g., 8453 for Base, defaults to 8453 if not provided)

Implementation Reference

src/toolService.js:580-595 (handler)

Main handler function for the 'get_gasless_approval_tokens' MCP tool. Extracts chainId (defaults to Base 8453), delegates to AgService, wraps response with metadata.

async getGaslessApprovalTokens(params = {}) {
  // Default to Base chain if no chainId provided
  const chainId = params.chainId || 8453;

  const result = await this.agg.getGaslessApprovalTokens(chainId);

  return {
    message: "Gasless approval tokens retrieved successfully",
    data: result,
    summary: `Found ${
      result.tokens?.length || 0
    } tokens supporting gasless approvals on chain ${chainId}`,
    note: "These tokens support EIP-2612 permit or meta-transaction approvals",
    chainId,
  };
}

src/index.js:754-767 (schema)

MCP tool schema definition including inputSchema for 'get_gasless_approval_tokens' in the ListToolsRequestHandler.

name: TOOL_NAMES.GET_GASLESS_APPROVAL_TOKENS,
description:
  "Get list of tokens that support gasless approvals (EIP-2612 permit)",
inputSchema: {
  type: "object",
  properties: {
    chainId: {
      type: "integer",
      description:
        "Blockchain ID (e.g., 8453 for Base, defaults to 8453 if not provided)",
    },
  },
  required: [],
},

src/index.js:1158-1160 (registration)
Tool dispatch/registration in the CallToolRequestHandler switch statement, mapping tool name to handler.
```
case TOOL_NAMES.GET_GASLESS_APPROVAL_TOKENS:
  result = await toolService.getGaslessApprovalTokens(args);
  break;
```

src/services/agService.js:226-244 (helper)

Helper service method in AgService that makes the actual API call to retrieve gasless approval tokens.

async getGaslessApprovalTokens(chainId) {
  try {
    const response = await fetch(`${this.baseUrl}/api/swap/gasless/approval-tokens?chainId=${chainId}`);
    
    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 approval tokens request failed');
    }
    
    return data.data;
  } catch (error) {
    throw new Error(`Failed to get gasless approval tokens: ${error.message}`);
  }
}

src/constants.js:16-16 (registration)
Constant definition for the tool name used throughout the codebase.
```
GET_GASLESS_APPROVAL_TOKENS: "get_gasless_approval_tokens",
```

DeFi Trading Agent MCP Server