Open source · MQTT · mTLS · 1NCE

Open IoT playground for ESP32-S3, Adrastea-I and 1NCE.

ESPnarrow helps developers quickly build and test complete IoT systems: an open-source embedded board, a public test MQTT broker, temporary client certificates and a Node-RED web dashboard.

View devices Generate MQTT certificate
ESP32-S3

Modern microcontroller for embedded firmware, field testing and rapid prototyping.

Würth Elektronik Adrastea-I

Compact cellular modem for narrowband IoT and LTE-M connectivity.

eSIM 1NCE

Cellular connectivity designed for IoT test and deployment scenarios.

Open source

GitLab library and board schematics intended to be shared with the community.

Generate a temporary MQTT certificate

Devices connect to the broker through mTLS. The generated certificate is limited to a maximum of 30 days and the private key is never displayed on the page: it is provided only inside a downloadable archive.

How to test in 3 steps

1
Generate a certificate

Create an mTLS archive for your device with a unique Device ID.

2
Flash or configure

Add the CA, client certificate, private key and MQTT topic to your firmware.

3
Publish and visualize

Publish birth, heartbeat, telemetry or info messages, then track the device state in the dashboard.

Standalone architecture

The Docker stack bundles Node-RED, Mosquitto and Caddy. The external ESPnarrow API key stays server-side and is never sent to the browser.

Device ESPnarrowESP32-S3 + Adrastea-I + 1NCE
Mosquitto MQTTTLS/mTLS, shared topic access
Node-RED DashboardPublic UI + internal APIs
ESPnarrow APIServer-side enrichment via X-Narrow-API-Key