A client came to me with a problem. They were selling electronics on Amazon and kept getting undercut by competitors. One week they'd price their product at $120, thinking they were competitive. Then suddenly, sales would dry up. They'd check the listings and find out a competitor had dropped to $72 three days ago.
By the time they noticed and adjusted their pricing, they'd already lost significant revenue.
They needed a way to monitor competitor prices in real-time and react quickly. Manual checking wasn't cutting it anymore.
So we built an automated competitor price monitoring system.
Here's what it does
The client tells the system which competitor products to monitor. It finds them on Amazon, records the current price, and starts tracking.
Every day, it checks if any competitor has changed their price. When a competitor drops their price, the client gets an immediate email notification with the details.
No dashboard to constantly monitor. No manual checking. Just alerts when something actually matters.
The workflow
We went with N8N since the client already had it running for other automation tasks, but this could easily be done with Make, Zapier, or even just a cron job with some Python scripts.
When adding a competitor product to track:
- An MCP tool (from the MCP360 server)
- It returns the competitor's product with current price, rating, and seller details
- The system saves this to a database—this becomes the baseline for comparison
The daily check:
- A scheduled job runs every morning at 6 AM
- It loops through every competitor product in the database
- For each one, it fetches the current price from Amazon
- If current price ≠ last recorded price, send email notification
- Update the database with the new price
The email notification:
- Plain text
- Competitor product name, old price, new price, percentage change, link
- Simple and actionable
Why this approach works
Most competitor monitoring tools are enterprise-level solutions with monthly fees that don't make sense for smaller sellers. Or they're generic price trackers that weren't built with competitive intelligence in mind.
This system focuses specifically on what matters to Amazon sellers: knowing when competitors move on price so you can respond strategically.
The conversational interface took a bit of extra work, but the client loved it. Instead of filling out forms or importing spreadsheets of ASINs, they just describe which products they want to monitor. It's faster and more intuitive.
The actual code structure
Here's the basic architecture we implemented:
Database schema:
competitor_products
├── id
├── product_name
├── product_url(ASIN)
├── current_price
├── user_email
├── created_at
└── updated_at
N8N workflows:
- Chat interface workflow (handles user interaction)
- Price check workflow (runs daily via cron)
- Email notification workflow (triggered when price drops)
MCP360 integration:
The MCP tool handles all the Amazon API complexity. We just pass it a search query and get back structured product data. No scraping, no worrying about rate limits or API changes.
Things we learned
Check frequency matters for competitive response. We initially set this to check every hour, but then we made it to daily checks at 6 AM works.
Track all price changes, not just drops. Originally we only alerted on price decreases, but price increases are also valuable intelligence. If a competitor raises prices, that's an opportunity.
Context matters more than raw numbers. We added fields for competitor seller name and percentage change. Knowing that "Seller X dropped 15%" is more actionable than just seeing "$120 → $102."
Amazon's pricing is dynamic. The same ASIN can have different prices from different sellers. The MCP tool returns the Buy Box price, which is what most customers see and what actually matters competitively.
What we'd add next
If we were expanding this, we'd probably include:
- Automatic price adjustment suggestions based on competitor moves
- Historical price charts to identify patterns
- Multiple competitor tracking per product category
- Slack or SMS alerts for urgent price changes
- Integration with the client's repricing tool
But for the initial scope, this gives the client exactly what they need to stay competitive.
The actual results
Three weeks after deployment:
- 8 competitor products being monitored
- 12 price change notifications sent
- Average response time reduced from 3 days to same-day
- Estimated revenue protection of $2,400 from faster competitive response
More importantly, the client stopped obsessively checking competitor listings. They can focus on running their business while the system handles monitoring. When something changes, they know immediately.
Tech stack breakdown
The tools we used:
- N8N - workflow automation (self-hosted or cloud)
- MCP360 - provides the Amazon product data tools via MCP
- N8N Table - for the storing product data
- SMTP - for email (using Gmail's SMTP)
The whole thing runs on a $5/month VPS. Could easily run on a Raspberry Pi for a fully self-hosted solution.
If you're working on something similar and want to see the actual N8N workflow setup or dive into the technical implementation, feel free to reach out.
Custom automation doesn't have to be complicated or expensive. This project took a weekend, runs on a $5/month server, and gives a small Amazon seller the kind of competitive intelligence that used to require enterprise-level tools.
Sometimes the best solutions are the ones built for a specific problem, not the ones trying to do everything.
Building tools for e-commerce sellers or working on similar competitive intelligence projects? I'd be interested to hear what's working in this space.
Top comments (1)
Hey, really enjoyed your write-up! Clear, practical, and nicely scoped.
I’m not directly in e-commerce or price-tracking, but your workflow approach really resonated. I’ve been experimenting with n8n in projects like this one, migrating from Pocket to Wallabag. Seeing how you’ve organized alerts and data checks is super interesting.
If you’re open to sharing, I’d love to peek at your workflow setup — especially how you handle rate limits, retries, and notifications. Feels like there’s a lot to learn from that pattern beyond e-commerce!