> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nexalis.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Main services

This section explains how to configure, install, and operate the Nexalis Agent launcher on Windows, Docker and Linux build.

It is designed for technical users (e.g., SCADA engineers) who want to set up the Nexalis Agent into their environment.

## 1) Overview: NexalisAgent and NexalisAgentService

`NexalisAgent` is a command-line control utility.
`NexalisAgentService` is the long-running service responsible for starting, monitoring, and restarting gRPC\_kafka and all configured connectors.

The agent logs are always inside `logs/NexalisAgentService/`.
NexalisAgent accepts a series of commands like `start`, `restart`, `status`, `reload`.

## 2) How to configure Nexalis Agent config file (`config.json`)

`config.json` must be in the same folder as `NexalisAgent` executable. It lists devices per connector type:

```json theme={null}
{
  "first_connector_type": [
    {
      "deviceModel": "./connector/device_models/model.json",
      "communicationAddress": "IP:PORT or SERIAL:PORT",
      "siteName": "siteName",
      "deviceID": "unique-device-id"
    }
  ],
  "other_connector_type": [
    { "...": "..." },
    { "...": "..." }
  ]
}
```

**OPC UA example with two clients**

```json theme={null}
{
  "opcua_connector": [
    {
      "deviceModel": "./device_models/OPCUA_Solar_SITENAME.json",
      "communicationAddress": "opc.tcp://[IP]:[PORT]",
      "siteName": "SITENAME",
      "deviceID": "OPCUA_Solar_SITENAME"
    },
    {
      "deviceModel": "./device_models/OPCUA_BESS_SITENAME.json",
      "communicationAddress": "opc.tcp://[IP]:[PORT]",
      "siteName": "SITENAME",
      "deviceID": "OPCUA_BESS_SITENAME"
    }
  ]
}
```

**Mixed example (2 Modbus clients + 1 DNP3 client)**

```json theme={null}
{
  "modbus_connector": [
    {
      "deviceModel": "./device_models/inverter1.json",
      "communicationAddress": "localhost:50001",
      "siteName": "My site",
      "deviceID": "Inverter_1"
    },
    {
      "deviceModel": "./device_models/inverter2.json",
      "communicationAddress": "localhost:50002",
      "siteName": "My site",
      "deviceID": "Inverter_2"
    }
  ],
  "dnp3_connector": [
    {
      "deviceModel": "./device_models/outstation.json",
      "communicationAddress": "localhost:50003",
      "siteName": "My site",
      "deviceID": "Outstation"
    }
  ]
}
```

> **gRPC\_kafka only:** use an **empty** `config.json` (`{}`) to start without connectors.

### Fields required per device

* `deviceModel` — path to the connector’s device-specific config (absolute or relative to the **connector executable**)
* `communicationAddress` — IP:port or serial; formats depend on connector
* `siteName` — groups devices by physical site
* `deviceID` — unique identifier within your fleet