Paloma DEX MCP Server

Instructions

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"