Paloma DEX MCP Server

Instructions

Args:
    chain_id: Chain ID (1, 10, 56, 100, 137, 8453, 42161)

Returns:
    JSON string with available trading tokens and their information.

Implementation Reference

• padex.py:1277-1349 (handler)

  Handler function for the 'get_available_trading_tokens' MCP tool. Retrieves trading tokens for a chain using PalomaDEXAPI or fallback mock data, returns JSON with token info.

  @mcp.tool()
  async def get_available_trading_tokens(ctx: Context, chain_id: str) -> str:
      """Get available tokens for trading on a specific chain.
      
      Args:
          chain_id: Chain ID (1, 10, 56, 100, 137, 8453, 42161)
      
      Returns:
          JSON string with available trading tokens and their information.
      """
      try:
          paloma_ctx = ctx.request_context.lifespan_context
          
          if chain_id not in CHAIN_CONFIGS:
              return f"Error: Unsupported chain ID {chain_id}"
          
          config = CHAIN_CONFIGS[chain_id]
          chain_name = get_chain_name_for_api(chain_id)
          
          if not chain_name:
              return f"Error: Chain name mapping not found for chain ID {chain_id}"
          
          # Use our Paloma-based API implementation
          try:
              tokens_data = await paloma_ctx.palomadex_api.get_tokens(chain_id)
              
              result = {
                  "chain": config.name,
                  "chain_id": config.chain_id,
                  "trader_contract": TRADER_ADDRESSES.get(chain_id, "Not configured"),
                  "total_tokens": len(tokens_data),
                  "tradeable_tokens": len([t for t in tokens_data if t.get('is_pair_exist', False)]),
                  "tokens": tokens_data,
                  "data_source": "paloma_dex_api"
              }
              
              return json.dumps(result, indent=2)
          except Exception as api_error:
              logger.warning(f"Paloma API failed: {api_error}, using fallback")
              
              # Fallback: Return common tokens that are likely available for trading
              common_tokens = []
              
              if chain_id == ChainID.ETHEREUM_MAIN:
                  common_tokens = [
                      {"erc20_name": "USD Coin", "erc20_symbol": "USDC", "erc20_address": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", "erc20_decimals": 6, "is_pair_exist": True},
                      {"erc20_name": "Tether USD", "erc20_symbol": "USDT", "erc20_address": "0xdAC17F958D2ee523a2206206994597C13D831ec7", "erc20_decimals": 6, "is_pair_exist": True},
                      {"erc20_name": "Wrapped Ether", "erc20_symbol": "WETH", "erc20_address": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2", "erc20_decimals": 18, "is_pair_exist": True}
                  ]
              elif chain_id == ChainID.ARBITRUM_MAIN:
                  common_tokens = [
                      {"erc20_name": "USD Coin", "erc20_symbol": "USDC", "erc20_address": "0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8", "erc20_decimals": 6, "is_pair_exist": True},
                      {"erc20_name": "Tether USD", "erc20_symbol": "USDT", "erc20_address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9", "erc20_decimals": 6, "is_pair_exist": True}
                  ]
              # Add more chains as needed
              
              result = {
                  "chain": config.name,
                  "chain_id": config.chain_id,
                  "trader_contract": TRADER_ADDRESSES.get(chain_id, "Not configured"),
                  "note": "Using fallback token list - Paloma API unavailable",
                  "total_tokens": len(common_tokens),
                  "tradeable_tokens": len(common_tokens),
                  "tokens": common_tokens,
                  "data_source": "fallback"
              }
              
              return json.dumps(result, indent=2)
                  
      except Exception as e:
          logger.error(f"Error getting available tokens: {e}")
          return f"Error getting available tokens: {str(e)}"

• padex.py:421-438 (helper)

  PalomaDEXAPI.get_tokens helper method called by the handler. Provides mock data for available ERC20 tokens on Ethereum and Arbitrum chains.

  async def get_tokens(self, chain_id: str) -> List[Dict]:
      """Get available tokens for a chain (mock implementation)."""
      # In real implementation, this would query the factory contract
      # For now, return common tokens per chain
      common_tokens = {
          "1": [  # Ethereum
              {"erc20_name": "USD Coin", "erc20_symbol": "USDC", "erc20_address": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", "erc20_decimals": 6, "is_pair_exist": True},
              {"erc20_name": "Tether USD", "erc20_symbol": "USDT", "erc20_address": "0xdAC17F958D2ee523a2206206994597C13D831ec7", "erc20_decimals": 6, "is_pair_exist": True},
              {"erc20_name": "Wrapped Ether", "erc20_symbol": "WETH", "erc20_address": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2", "erc20_decimals": 18, "is_pair_exist": True}
          ],
          "42161": [  # Arbitrum
              {"erc20_name": "USD Coin", "erc20_symbol": "USDC", "erc20_address": "0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8", "erc20_decimals": 6, "is_pair_exist": True},
              {"erc20_name": "Tether USD", "erc20_symbol": "USDT", "erc20_address": "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9", "erc20_decimals": 6, "is_pair_exist": True}
          ]
      }
      
      return common_tokens.get(chain_id, [])

• padex.py:833-845 (helper)

  Helper function to map chain_id to lowercase chain name used in Paloma DEX API calls.

  def get_chain_name_for_api(chain_id: str) -> Optional[str]:
      """Map chain ID to chain name for Paloma DEX API calls."""
      chain_name_mapping = {
          "1": "ethereum",
          "10": "optimism", 
          "56": "bsc",
          "100": "gnosis",
          "137": "polygon",
          "8453": "base",
          "42161": "arbitrum"
      }
      return chain_name_mapping.get(chain_id)