# Dev Log: Add ASIN Column to Active Inventory Tab

**Date:** 2026-05-24
**Author:** Jules (AI Agent)
**Status:** Success

## Overview
The goal of this task was to add an "ASIN" column to the "Active Inventory" tab on the Tracking page, positioned immediately to the left of the "SKU" column. This allows users to easily identify the corresponding Amazon product without needing to cross-reference data elsewhere.

## Analysis and Implementation
1. **Data Sourcing:**
   - I identified that the frontend fetches the Active Inventory data from the `/api/tracking/active` endpoint in `wsgi_handler.py`.
   - This endpoint queries the `inventory_ledger` database table using a `SELECT *` query.
   - Upon reviewing the `inventory_ledger` table schema (in `keepa_deals/db_utils.py`), I verified that the `asin` column is already stored in the table. Consequently, no database schema changes, JOINs, or backend modifications were necessary.

2. **Frontend Updates (`templates/tracking.html`):**
   - Modified the `renderActive(items)` JavaScript function.
   - Added a `<th>ASIN</th>` header in the exact position requested (before the `<th>SKU</th>` header).
   - Injected the ASIN data into the row template `<td>${item.asin || '—'}</td>`, properly implementing the edge case requirement to use an em dash (—) instead of 'undefined' or 'null' when the ASIN data is missing. No hyperlinking was added, per instructions.
   - Incrementally updated the spacer row from `<td colspan="5">` to `<td colspan="6">` to maintain proper table alignment with the new 6-column layout.

## Edge Cases Handled
- **Missing Data:** If an ASIN is missing or undefined for a specific inventory row, the UI now correctly renders a plain text em dash (—) instead of displaying "undefined".
- **Schema Impact:** Because the ASIN was already present natively on the target table, no complex JOINs were required, avoiding any potential deduplication or multiple-row-per-inventory edge cases.

## Results
The task was successfully completed. The Active Inventory table now displays the correct ASIN natively, and the formatting is consistent with instructions. All local core tests passed.