Track Technology Changes Over Time with the /changes API

Knowing what technologies a website uses right now is useful. Knowing when they changed is where the real value is. Did a competitor switch from Angular to React? Did a prospect drop their analytics platform? Did a client quietly adopt a vulnerable library?

The /changes API endpoint gives you a queryable feed of every technology change detected across scanned domains. Every time a scan finds a difference from the previous snapshot, it records the change: added, removed, or version changed.

How It Works

Every call to /analyze creates a versioned snapshot of the domain's tech stack. Behind the scenes, DetectZeStack diffs the new snapshot against the previous one using the same change detection algorithm that powers webhook monitoring. When differences are found, they're recorded as structured change events.

Three types of changes are tracked:

• added — a technology appeared that wasn't in the previous scan
• removed — a technology was present before but is now gone
• version_changed — the same technology is still present but at a different version

Querying the Change Feed

The GET /changes endpoint returns recent changes with optional filtering by domain:

curl -H "X-RapidAPI-Key: YOUR_KEY" \
     -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" \
     "https://detectzestack.p.rapidapi.com/changes?domain=stripe.com"

Response:

{
  "changes": [
    {
      "domain": "stripe.com",
      "technology": "React",
      "change_type": "added",
      "category": "JavaScript frameworks",
      "created_at": "2026-03-08T14:22:00Z"
    },
    {
      "domain": "stripe.com",
      "technology": "jQuery",
      "change_type": "removed",
      "category": "JavaScript libraries",
      "created_at": "2026-03-08T14:22:00Z"
    }
  ],
  "count": 2,
  "history_days": 90,
  "tier": "pro"
}

Tier-Gated History

How far back you can look depends on your plan:

The response includes history_days and tier so your application knows the data window without hardcoding tier logic.

Inline Changes with /history

If you already use the /history endpoint to retrieve snapshots, you can get change diffs inline by adding include_changes=true. Each snapshot in the response will include a changes array showing what was added, removed, or version-changed since the previous snapshot:

curl -H "X-RapidAPI-Key: YOUR_KEY" \
     -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" \
     "https://detectzestack.p.rapidapi.com/history?domain=stripe.com&include_changes=true"

This is useful when you want both the full snapshot and the diff in a single call, without making a separate request to /changes.

Use Cases

Competitive intelligence

Track when competitors adopt new frameworks, switch analytics providers, or migrate infrastructure. If your competitor moves from Heroku to AWS, that signals serious scale investment. If they add Stripe, they're likely launching payments.

Sales prospecting

A prospect removing their current CRM or marketing automation tool is a buying signal. Poll the change feed for your target accounts and trigger outreach when their stack shifts.

Migration tracking

If you're a consulting firm helping clients migrate from Angular to React, the change feed lets you verify progress programmatically. No more asking "have you deployed yet?" — just check the changes.

Security monitoring

Combine with the /analyze endpoint's CPE identifiers to detect when a domain starts using a technology with known vulnerabilities. A version change from jQuery 3.5 to 3.6 means something different than a change from 3.6 to 2.1.

BuiltWith Comparison

BuiltWith offers historical technology tracking at $295/month. DetectZeStack gives you the same capability — a structured change feed with domain filtering and tier-gated history — starting at $0/month on the free tier. The Mega plan at $79/month gives you a full year of history plus 50,000 API requests.