This is a test server. It's meant for connecting Meshtastic radios for distance communications. It doesn't support TLS, but neither do the airwaves. Ensure you enable mqtt.encryption_enabled on your radio so that it forwards protobufs as-is without decrypting them first.

All recommended Meshtastic settings:

Setting Value Note
mqtt.enabled true No MQTT without this
mqtt.address mqtt.honeypot.net
mqtt.username defcon
mqtt.password 2025
mqtt.encryption_enabled true Turn this on! Otherwise your radio will decrypt packets before sending them to the MQTT server.
mqtt.json_enabled false This is being deprecated. nRF52 radios don't support it at all.
mqtt.tls_enabled true if it works on your radio, but false is OK Meshtastic has its own encryption. In any case, we usually send packets over the air and that's not encrypted at all, so not adding TLS here isn't making it less secure.
mqtt.root msh
mqtt.proxy_to_client_enabled false (but true if you're tethered to a phone or laptop)
mqtt.map_reporting_enabled false Don't send locations of all your local nodes to MQTT

Quick setup of the "DefCon" channel

Assuming you want to use channel 2 to chat over MQTT:

meshtastic --port --ch-set name "DefCon" --ch-set psk base64:vipbUmGGts4ufJMPqMtNvMUvOR4ri8YmAw5YvP1A+Go= --ch-set uplink_enabled true --ch-set downlink_enabled true --ch-set module_settings.position_precision 13 --ch-index 2