JSON output option for Home Assistant Text Sensor

[philpem]

Component name

text_sensor, homeassistant platform

Link to component documentation on our website

https://esphome.io/components/text_sensor/homeassistant/

Describe the enhancement

Currently if a complex attribute is passed in (one represented as Python dicts, lists and objects) the Text Sensor will send a Python-syntax string representation from Home Assistant to the ESPHome device. This is hard to deserialise in ESPhome and involves either string replacements to convert the code to JSON, or writing a parser from scratch.

It would be nice to have an option for the Home Assistant Text Sensor so that objects like this could be represented as JSON, e.g.:

text_sensor:
  - platform: homeassistant
    id: octopus_tomorrow_rates
    entity_id: event.octopus_energy_electricity_today_rates
    attribute: rates
    encoding: json

Use cases

This would allow me to more easily pull the data from the Octopus Energy Integration (https://bottlecapdave.github.io/HomeAssistant-OctopusEnergy/entities/electricity/#current-day-rates) into the ESP32 which runs my solar energy system.
I'd like to use this data to optimise the charging of the battery from grid, to charge the battery when energy is cheap and prevent charging during expensive peak periods.

(My inverter doesn't integrate with my energy supplier so I'm having to write this myself)

Anything else?

Octopus Energy integration: https://bottlecapdave.github.io/HomeAssistant-OctopusEnergy

Details of the current day rates data format: https://bottlecapdave.github.io/HomeAssistant-OctopusEnergy/entities/electricity/#current-day-rates

Shortened example of the data the Text Sensor currently sends to the ESPHome device:

[D][homeassistant.text_sensor:014]: 'event.octopus_energy_electricity_REDACTED_current_day_rates::rates': Got attribute state '[{'start': datetime.datetime(2025, 8, 21, 0, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 21, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat': 0.16611, 'is_capped': False}, {'start': datetime.datetime(2025, 8, 21, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025
[D][text_sensor:069]: 'octopus_today_rates': Sending state '[{'start': datetime.datetime(2025, 8, 21, 0, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 21, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat': 0.16611, 'is_capped': False}, {'start': datetime.datetime(2025, 8, 21, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 21, 1, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat': 0.1

[D][homeassistant.text_sensor:014]: 'event.octopus_energy_electricity_REDACTED_next_day_rates::rates': Got attribute state '[{'start': datetime.datetime(2025, 8, 22, 0, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 22, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat': 0.173355, 'is_capped': False}, {'start': datetime.datetime(2025, 8, 22, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 
[D][text_sensor:069]: 'octopus_tomorrow_rates': Sending state '[{'start': datetime.datetime(2025, 8, 22, 0, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 22, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat': 0.173355, 'is_capped': False}, {'start': datetime.datetime(2025, 8, 22, 0, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'end': datetime.datetime(2025, 8, 22, 1, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London')), 'value_inc_vat':

(Redacted content is my electricity meter's serial number)

[jesserockz]

I could be wrong, but I have a feeling that any integration that is actually merged into HA would not expose the attributes directly as python objects like that.

Can you reproduce this with any built-in integration?

[philpem]

The only integration I can think of which does something similar is Forecast Solar, and as far as I can tell it only makes the forecast data visible to the Energy Dashboard.

The use case here is the same as the one which triggered esphome/esphome#10421

At the moment I'm working around the 'throwing large object representations around' problem by doing this in Python on the machine hosting my Home Assistant VM, querying the energy provider API, and using HASS REST API calls to set the timers.
At this point the data in HASS is only being used for a pretty "cheap rate" indicator on one of my dashboards.