GPTastic Home Assistant Add-on

Overview

GPTastic is a Home Assistant add-on that acts as a bridge between MQTT, OpenAI, and Home Assistant entities. It listens for incoming MQTT messages, forwards those messages to the OpenAI API for processing, validates the response, and then updates a Home Assistant entity based on the result.

The add-on is designed to integrate AI-driven decisions into Home Assistant automations in a structured and predictable way.

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What the Add-on Does

At a high level, GPTastic:

• Subscribes to an MQTT topic
• Receives messages from Home Assistant or external systems
• Sends those messages to the OpenAI API
• Requires the AI to respond in a strict CSV format:

  entity_name,value
  

• Validates the response format
• Updates the specified Home Assistant entity with the provided value

This allows AI-generated decisions or text to be safely consumed by Home Assistant automations.

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Workflow Steps

1. GPTastic Add-on Startup

• The GPTastic add-on starts.
• It subscribes to the MQTT topic:

  gptastic/incoming
  

2. MQTT Message Published

• An MQTT client publishes a message to the Home Assistant MQTT broker.
• The message is sent on:

  gptastic/incoming
  

Example payload:

Will it be sunny tomorrow morning in Pretoria at around 7 ? Only respond with gptastic_usebattery,No or gptastic_usebattery,Yes

3. GPTastic Sends Request to OpenAI

• GPTastic receives the MQTT message.
• It sends the message to the OpenAI API.
• GPTastic instructs the AI to respond only in the following CSV format:

  entity_name,value
  

Example response:

gptastic_usebattery,No

4. CSV Validation

• GPTastic receives the AI response.
• It verifies that:
  • The response is valid CSV
  • Exactly two values are present
  • The first value is an entity name
  • The second value is the entity state or value

Invalid responses are rejected.

5. Update Home Assistant Entity

• GPTastic uses the validated CSV data.
• It updates the Home Assistant entity specified in the response.
• The entity state is set to the provided value.

Example result:

sensor.gptastic_usebattery = No

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Example Use Cases

Battery Usage Decision

MQTT Input

Will it be sunny tomorrow morning in Pretoria at around 7 ? Only respond with gptastic_usebattery,No or gptastic_usebattery,Yes

AI Response

gptastic_usebattery,Yes

Home Assistant Result

• sensor.gptastic_usebattery is set to Yes
• Automations can act on this value

Mode Selection

MQTT Input

Decide which operating mode the system should use tomorrow.

AI Response

gptastic_mode,eco

Home Assistant Result

• sensor.gptastic_mode is set to eco

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Summary

GPTastic enables controlled use of AI-generated decisions inside Home Assistant by:

• Receiving prompts over MQTT
• Delegating reasoning to OpenAI
• Enforcing strict response formatting
• Updating Home Assistant entities safely

This makes it suitable for automation scenarios where AI output must remain predictable and structured.