Paloma DEX MCP Server

Instructions

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

Returns:
    JSON string with chain configuration and status.

Implementation Reference

• padex.py:600-649 (handler)

  The handler function for the 'get_chain_info' tool. It is decorated with @mcp.tool() for automatic registration in FastMCP. Retrieves chain configuration from CHAIN_CONFIGS, checks Web3 connection status, fetches latest block number, and returns formatted JSON with chain details.

  @mcp.tool()
  async def get_chain_info(ctx: Context, chain_id: str) -> str:
      """Get detailed information about a specific chain.
      
      Args:
          chain_id: Chain ID (1, 10, 56, 100, 137, 8453, 42161)
      
      Returns:
          JSON string with chain configuration and status.
      """
      try:
          paloma_ctx = ctx.request_context.lifespan_context
          
          if chain_id not in CHAIN_CONFIGS:
              available_chains = [str(k) for k in CHAIN_CONFIGS.keys()]
              return f"Error: Unsupported chain ID '{chain_id}'. Available: {available_chains}"
          
          config = CHAIN_CONFIGS[chain_id]
          
          chain_info = {
              "chain_id": config.chain_id,
              "name": config.name,
              "rpc_url": config.rpc_url,
              "explorer_url": config.explorer_url,
              "gas_price_gwei": config.gas_price_gwei,
              "contracts": {
                  "pusd_token": config.pusd_token or "Not configured",
                  "pusd_connector": config.pusd_connector or "Not configured",
                  "etf_connector": config.etf_connector or "Not configured"
              }
          }
          
          # Add connection status
          if chain_id in paloma_ctx.web3_clients:
              try:
                  web3 = paloma_ctx.web3_clients[chain_id]
                  latest_block = web3.eth.get_block('latest')
                  chain_info["status"] = "connected"
                  chain_info["latest_block"] = latest_block.number
              except Exception as e:
                  chain_info["status"] = f"connection_error: {str(e)}"
          else:
              chain_info["status"] = "not_connected"
          
          return json.dumps(chain_info, indent=2)
          
      except Exception as e:
          logger.error(f"Error getting chain info: {e}")
          return f"Error getting chain info: {str(e)}"

• padex.py:60-131 (helper)

  Global CHAIN_CONFIGS dictionary mapping ChainID enums to ChainConfig dataclasses. Provides RPC URLs, contract addresses (PUSD, connectors), explorer URLs, and gas prices for all 7 supported EVM chains. Directly used by get_chain_info to populate chain_info dict.

  CHAIN_CONFIGS = {
      ChainID.ETHEREUM_MAIN: ChainConfig(
          chain_id=1,
          name="Ethereum",
          rpc_url="https://eth.llamarpc.com",
          pusd_token=os.getenv("PUSD_TOKEN_ETH", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_ETH", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_ETH", ""),
          explorer_url="https://etherscan.io",
          gas_price_gwei=30
      ),
      ChainID.ARBITRUM_MAIN: ChainConfig(
          chain_id=42161,
          name="Arbitrum One",
          rpc_url="https://arb1.arbitrum.io/rpc",
          pusd_token=os.getenv("PUSD_TOKEN_ARB", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_ARB", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_ARB", ""),
          explorer_url="https://arbiscan.io",
          gas_price_gwei=1
      ),
      ChainID.OPTIMISM_MAIN: ChainConfig(
          chain_id=10,
          name="Optimism",
          rpc_url="https://mainnet.optimism.io",
          pusd_token=os.getenv("PUSD_TOKEN_OP", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_OP", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_OP", ""),
          explorer_url="https://optimistic.etherscan.io",
          gas_price_gwei=1
      ),
      ChainID.BASE_MAIN: ChainConfig(
          chain_id=8453,
          name="Base",
          rpc_url="https://mainnet.base.org",
          pusd_token=os.getenv("PUSD_TOKEN_BASE", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_BASE", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_BASE", ""),
          explorer_url="https://basescan.org",
          gas_price_gwei=1
      ),
      ChainID.BSC_MAIN: ChainConfig(
          chain_id=56,
          name="BNB Smart Chain",
          rpc_url="https://bsc-dataseed1.binance.org",
          pusd_token=os.getenv("PUSD_TOKEN_BSC", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_BSC", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_BSC", ""),
          explorer_url="https://bscscan.com",
          gas_price_gwei=5
      ),
      ChainID.POLYGON_MAIN: ChainConfig(
          chain_id=137,
          name="Polygon",
          rpc_url="https://polygon-rpc.com",
          pusd_token=os.getenv("PUSD_TOKEN_MATIC", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_MATIC", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_MATIC", ""),
          explorer_url="https://polygonscan.com",
          gas_price_gwei=30
      ),
      ChainID.GNOSIS_MAIN: ChainConfig(
          chain_id=100,
          name="Gnosis Chain",
          rpc_url="https://rpc.gnosischain.com",
          pusd_token=os.getenv("PUSD_TOKEN_GNOSIS", ""),
          pusd_connector=os.getenv("PUSD_CONNECTOR_GNOSIS", ""),
          etf_connector=os.getenv("ETF_CONNECTOR_GNOSIS", ""),
          explorer_url="https://gnosisscan.io",
          gas_price_gwei=2
      )
  }

• padex.py:47-57 (helper)

  Dataclass defining the structure for chain configurations used in CHAIN_CONFIGS and accessed by get_chain_info.

  @dataclass
  class ChainConfig:
      """Configuration for a blockchain network"""
      chain_id: int
      name: str
      rpc_url: str
      pusd_token: str
      pusd_connector: str
      etf_connector: str
      explorer_url: str
      gas_price_gwei: int = 20

• padex.py:38-45 (helper)

  Enum defining supported chain IDs as strings, used as keys in CHAIN_CONFIGS.

  class ChainID(str, Enum):
      ETHEREUM_MAIN = "1"
      OPTIMISM_MAIN = "10"
      BSC_MAIN = "56"
      POLYGON_MAIN = "137"
      BASE_MAIN = "8453"
      ARBITRUM_MAIN = "42161"
      GNOSIS_MAIN = "100"