Voice-driven Cart ↔ Shopping-list Sync

[eMeF1]

🤝 Contribute

This automation is still evolving! If you have ideas to improve usability, add new features, or fix edge cases — please let me know. It can be later turned into a Home Assistant Blueprint once the logic is refined and edge cases are handled.

🛒 Home Assistant × Rohlik.cz – Voice-driven Cart ↔ Shopping-list Sync

This automation lets anyone in the household say “Přidej mléko do nákupního seznamu” (or similar) and have:

1. Assist add the item to the HA Shopping list.
2. An automation immediately search the same product on Rohlik.cz and drop it in your online cart.
3. A script mirror the entire Rohlik cart back into the Shopping list

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Prerequisites

Component	Purpose
RohlikCZ integration	API access to your Rohlik account
Assist / Conversation agent	Voice input (uses GPT-4o-mini in example)
A todo.rohlik_shopping_list entity	Shopping list

---

1 · Conversational prompt

Add this to the “Instructions” field of your Assist - Conversation Agent - ⚙️ if you want to check for duplicities:

Při přidávání položky do nákupního seznamu zkontroluj, zda už na seznamu není. 
Pokud tam není, přidej ji bez dalšího potvrzení. 
Pokud tam už je, uveď její název a zeptej se uživatele, zda ji chce opravdu přidat znovu.

Effect: the LLM silently adds new items, but politely asks before creating duplicates.

⚠️ Known Limitation

If your voice command matches the built-in intent HassShoppingListAddItem, the request will be executed locally by Home Assistant, skipping the Conversation agent (LLM).
As a result, the duplicate check in the agent prompt will not be applied.

Workaround:
Rephrase your request to avoid triggering the default intent

---

2 · Script: mirror Rohlik cart → Shopping list

alias: "Rohlik cart to shopping list"
mode: single
sequence:
  # 1️⃣ Pull full cart
  - service: rohlikcz.get_cart_content
    data:
      config_entry_id: [your Rohlik device]
    response_variable: cart

  # 2️⃣ Build list ["Milk [2x]", "Bananas [6x]", …]
  - variables:
      product_names_with_quantity: >-
        {% set ns = namespace(lst=[]) %}
        {% for p in cart['products'] %}
          {% set ns.lst = ns.lst + [p.name ~ ' [' ~ (p.quantity | int) ~ 'x]'] %}
        {% endfor %}
        {{ ns.lst }}

  # 3️⃣ Wipe current list (mark → clear)
  - service: shopping_list.complete_all
  - service: shopping_list.clear_completed_items

  # 4️⃣ Re-create each cart line
  - repeat:
      for_each: "{{ product_names_with_quantity }}"
      sequence:
        - service: todo.add_item
          target:
            entity_id: todo.rohlik_shopping_list
          data:
            item: "{{ repeat.item }}"

⚠️ Known Limitation: Outdated Shopping List

The script that syncs the Rohlik cart to the shopping list (script.rohlik_cart_to_shopping_list) is currently triggered only when an item is picked by automation below.

This means the shopping list may become outdated if:

• Items are manually added to the Rohlik cart (e.g. via app or website)
• No new item has been added by voice recently

As a result, the Conversation agent may not be aware of what's already in the cart, and could allow duplicates unintentionally.

🧩 Open Question:
What is the best way to keep the shopping list up to date without using time-based automations (which I’m trying to avoid)?

---

3 · Automation: new spoken item → Rohlik cart

alias: "Rohlik Add Item From Shopping List to Cart"
mode: single

## 🔔 Trigger whenever the list length increases
trigger:
  - platform: state
    entity_id: todo.rohlik_shopping_list

## 📝 Ensure we’re reacting to an *addition*, not a removal
condition:
  - "{{ (trigger.to_state.state | int(0)) > (trigger.from_state.state | int(0)) }}"

## ▶️ Actions
action:
  # 1️⃣ Fetch full list → pick **last** item (the newly added one)
  - service: todo.get_items
    target: {entity_id: todo.rohlik_shopping_list}
    response_variable: shopping_list

  - variables:
      last_item: "{{ shopping_list['todo.rohlik_shopping_list']['items'][-1]['summary'] }}"

  # 2️⃣ Ignore items written by the sync-script (they contain “[2x]” etc.)
  - condition: "{{ '[' not in last_item }}"

  # 3️⃣ Add to Rohlik last_item
  - service: rohlikcz.search_and_add_to_cart
    data:
      config_entry_id: [your Rohlik device]
      product_name: "{{ last_item }}"
      quantity: 1

  # 4️⃣ Refresh local list so quantities stay in sync
  - service: script.rohlik_cart_to_shopping_list

⚠️ Known Limitation: Only One New Item Handled

If multiple new items (without [x] suffix) are added to the shopping list at once the automation currently processes only the most recent one ([-1] in the list).

This means:

• Only the last added item will be sent to the Rohlik cart
• Other new items will be removed during cart->shopping list sync while processing the first item

📝 Note:
This issue should not occur when using Assist via voice, as it adds only one item per request.

[eMeF1]

Obsolete after v0.3.0-beta