Agent Skill
2/7/2026

weight-track-database

Describes the structure of the weight tracker database that allows to store and read weight records for the user

M
marcopeg
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SKILL.md

Nameweight-track-database
DescriptionDescribes the structure of the weight tracker database that allows to store and read weight records for the user

name: Weight Track Database description: Describes the structure of the weight tracker database that allows to store and read weight records for the user version: 1.0.0

Overview

The Weight Tracker database uses a JSON file to store weight entries provided by the user.

File Location

The data file is available at {root}/db/weight-tracker.json

Writing to the db

  1. Before writing into the db, identify which is the best approach:
  • in-memory change: load the entire file in-memory, apply the change, serialize it back
  • text-based change: scan the file in text mode and apply the change as a patch
  1. Isolate the atomical change you want to apply

  2. Read existing data to understand which kind of operation is needed

  • insert
  • update
  • delete
  1. Apply the change with the identified approach.

ALWAYS: explain the execution plan to the user as output in the chat

Reading from the DB

  1. Identify the best approach to the read request:
  • in-memory change: load the entire file in-memory, evaluate logic to perform the read
  • text-based change: scan the file in text mode and calculate the expected information as context
  1. Perform the read of the pertinent information

  2. Perform aggregations if needed

ALWAYS: explain the execution plan to the user as output in the chat

Data Structure

Always ensure the database keeps a data structure like this:

{
  "2025": {
    "11": {
      "10": 99.0,
      "12": 99.5
    }
  }
}

More info:

  • the indexing of the data is: year -> month -> day
  • the value of a day is a number, the database is unit agnostic
  • if a new writing request targets an existing day, override the value for the day
Skills Info
Original Name:weight-track-databaseAuthor:marcopeg