# ESP32 Self-Hosted IoT Platform: Your First MQTT Message in 15 Minutes

> Source: <https://dev.to/kevin-thingboot/esp32-self-hosted-iot-platform-your-first-mqtt-message-in-15-minutes-4i6p>
> Published: 2026-11-06 04:42:53+00:00

*This article is cross-posted from the [ThingBoot Guides](https://github.com/Kevin-ThingBoot/thingboot-guides) repository on GitHub, where you'll also find the [Chinese version](https://github.com/Kevin-ThingBoot/thingboot-guides/blob/main/guides/01-esp32-mqtt-platform.zh-CN.md).*

Most ESP32 tutorials stop at "blink an LED". Real products need the next step:

get your device talking to a platform you **own** — not someone else's cloud.

This guide walks you from a stock ESP32 to publishing telemetry and receiving

commands over MQTT against a self-hosted broker. It takes about 15 minutes.

``` php
[ESP32] --WiFi--> [MQTT Broker (self-hosted)] ---> [Your apps / dashboards / AI agents]
         <-------- (commands, OTA triggers) ------
```

Self-hosting the broker means: your data stays on your network, you control

auth, and AI agents can talk to devices through the same topics later.

The fastest way to get a local broker:

```
docker run -d -p 1883:1883 --name mosquitto eclipse-mosquitto
```

Then create a minimal `mosquitto.conf` allowing local testing:

```
listener 1883
allow_anonymous true
```

For production: always enable auth + TLS. See the [OTA & safe-mode guide](https://github.com/Kevin-ThingBoot/thingboot-guides/blob/main/guides/02-esp32-ota-production.md).

Install the [ThingBoot ESP Arduino SDK](https://github.com/ThingBoot/thingboot-device-esp-arduino-sdk),

which wraps WiFi provisioning, MQTT reconnect, and OTA into a setup()/loop()

model. Or use plain Arduino with PubSubClient — the flow is the same:

```
#include <WiFi.h>
#include <PubSubClient.h>

WiFiClient net;
PubSubClient mqtt(net);

void setup() {
  Serial.begin(115200);
  WiFi.begin("YOUR_SSID", "YOUR_PASSWORD");
  while (WiFi.status() != WL_CONNECTED) delay(500);

  mqtt.setServer("192.168.1.100", 1883);   // your broker's LAN IP
  mqtt.setCallback([](char* topic, byte* payload, unsigned int len) {
    Serial.printf("command received on %s: %.*s\n", topic, len, (char*)payload);
  });
}

void loop() {
  if (!mqtt.connected()) mqtt.connect("esp32-demo");
  mqtt.loop();

  static uint32_t last = 0;
  if (millis() - last > 5000) {
    last = millis();
    mqtt.publish("things/esp32-demo/telemetry",
                 "{\"temp\":25.5,\"rssi\":-60}");
  }
}
```

Subscribe from your computer and watch data arrive:

```
mosquitto_sub -h 192.168.1.100 -t "things/#" -v
```

Then send a command back to the device:

```
mosquitto_pub -h 192.168.1.100 -t "things/esp32-demo/cmd" -m '{"relay":"on"}'
```

If you see telemetry flowing and the device reacting to commands — congratulations,

that's the entire foundation of an IoT fleet: **device → platform → device**.

| Goal | Guide | 
|---|---|
| OTA updates for production fleets (A/B partitions, rollback, safe mode) | [Part 2](https://github.com/Kevin-ThingBoot/thingboot-guides/blob/main/guides/02-esp32-ota-production.md) | 
| Letting an AI agent control devices via MCP | Part 3 (planned) | 
| Full SDK with provisioning + rollback | [ThingBoot SDKs](https://github.com/ThingBoot) | 

*ThingBoot provides free device SDKs and a self-hosted IoT platform.
Questions? Open an [issue](https://github.com/Kevin-ThingBoot/thingboot-guides/issues).*