Arbitrum MCP Server

Instructions

Implementation Reference

• src/index.ts:652-666 (handler)

  MCP tool handler for 'maintenance_status': resolves RPC URL or chain name, instantiates NitroNodeClient, calls getMaintenanceStatus(), formats and returns result as text content.

  case "maintenance_status": {
    const rpcUrl = await this.resolveRpcUrl(
      (args.rpcUrl as string) || (args.chainName as string)
    );
    const nodeClient = new NitroNodeClient(rpcUrl);
    const result = await nodeClient.getMaintenanceStatus();
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  }

• src/index.ts:1464-1483 (registration)

  Tool registration and input schema definition for 'maintenance_status' returned by listTools handler in getAvailableTools().

    name: "maintenance_status",
    description:
      "Check maintenance status - seconds since last maintenance (requires admin API)",
    inputSchema: {
      type: "object" as const,
      properties: {
        rpcUrl: {
          type: "string",
          description:
            "The RPC URL of the Arbitrum node (optional if default is set)",
        },
        chainName: {
          type: "string",
          description:
            "Chain name (e.g., 'Xai', 'Arbitrum One') - will auto-resolve to RPC URL",
        },
      },
      required: [],
    },
  },

• src/clients/nitro-node-client.ts:412-430 (helper)

  Core helper function getMaintenanceStatus() in NitroNodeClient that makes RPC call to 'maintenance_secondsSinceLastMaintenance' and returns MaintenanceStatus.

  async getMaintenanceStatus(): Promise<MaintenanceStatus> {
    try {
      const seconds = await this.makeRpcCall(
        "maintenance_secondsSinceLastMaintenance",
        []
      );
      return {
        secondsSinceLastMaintenance:
          typeof seconds === "number" ? seconds : parseInt(seconds, 10),
      };
    } catch (error) {
      return {
        secondsSinceLastMaintenance: -1,
        error: `Maintenance status not supported on this RPC endpoint: ${
          (error as Error).message
        }`,
      };
    }
  }

• src/clients/nitro-node-client.ts:45-48 (schema)

  TypeScript interface defining the MaintenanceStatus return type used by the tool.

  export interface MaintenanceStatus {
    secondsSinceLastMaintenance: number;
    error?: string;
  }