The REST API is build for interaction with the ESP 8266 firmware, and, the OpenTherm Gateway.

System API (v0)

GET /api/v0/devtime

Returns the device time

GET /api/v0/devinfo

Returns the device information

OTGW API (v0)

GET /api/v0/otgw/{msgid}

Returns the value of the {msgid} requested. The JSON contains: Msg description, Msg value, Msg Unit (if any). The msgid between 0 and 127 are used, 128+ are reserved according to the specification.

OTGW API (v1)

The API v1 adds a little more than this:

GET /api/v1/otgw/otmonitor/

Returns a JSON key value pair array, with all relevant OTGW monitor values.

GET /api/v1/otgw/telegraf/

Returns a JSON key value pair array, compatible with telegraf, with all relevant OTGW monitor values.

GET /api/v1/otgw/id/{msgid}

Returns the value of the {msgid} requested. The JSON contains: Msg description, Msg value, Msg Unit (if any). The msgid between 0 and 127 are used, 128+ are reserved according to the specification.

GET /api/v1/otgw/label/{msglabel}

Returns the value of the {msgid by label} that is requested. The JSON contains: Msg description, Msg value, Msg Unit (if any). The msgid between 0 and 127 are used, 128+ are reserved according to the specification.

POST /api/v1/otgw/command/{command text}

Post to this API and it will send the {command text} to the OTGW. Should return a simple OK. At this time it does not check the correct receive of the command by the OTGW.
warning: not fully battletested, it should work

I would like to write a Swagger API document, but that takes more time.