Building an Autonomous Competitor Price Monitor with Python, Playwright, and Discord (Zero SaaS Fees)

Description and use

An autonomous competitor price monitor built with Python, HTTPX, Playwright, SQLite, and Discord webhooks eliminates SaaS fees, offers resilient scraping, and provides real‑time alerts.

Problem

Missing competitor price changes by even a few hours can erode daily margins; commercial SaaS monitoring platforms are costly, fragile, and lack fine-grained control.

Outcome

The pipeline reduces cost to zero SaaS fees, improves resilience to dynamic DOM changes, and provides real‑time alerts with color coding for price changes.

Workflow

• Schedule cron job (15–60 min) → Tiered Scraper (HTTPX → Playwright fallback) → SQLite engine (compare & compute delta) → Discord alert dispatcher

Evidence

Missing a competitor's flash sale or midnight re‑pricing event by even three hours can wipe out daily margins.

Source

These platforms run between $150 and $800 per month, enforce arbitrary SKU tracking tiers, and frequently fail when target sites tweak dynamic DOM selectors or deploy basic JavaScript challenges.

Source

It leverages HTTPX for rapid REST/static scraping, Playwright with stealth parameters for client‑side rendered stores, SQLite for time‑series pricing and stock tracking, and Discord Webhooks for instant, color‑coded visual alerts.

Source