Build group grocery carts through a Signal-based agent

A self-hosted Signal agent drafts a grocery list from past orders, lets group members edit it, then logs into the store and builds and validates the cart; the author finishes checkout manually.

Done with a custom-built or unnamed agent

What they did

The author runs a self-hosted agent through Signal, with group chat limited to whitelisted accounts. It drafts a starter grocery list from past orders, kept locally or pulled from the store's site. Group members add or remove items. Then the agent uses a custom browser tool to log in, build the cart from the final list, search for extra requested items, and validate the cart.

How it went

Cart building works end to end. Checkout isn't automated: the author logs in and does the last two clicks manually, and may add automatic ordering later.

Worth knowing

The author held back from giving the agent spending power, so a manual final checkout is the safeguard if you copy this.

Source: HN · Feb 22, 2026