Auto Check Engine

The Auto Check Engine is the core technology that automatically monitors your USCIS case status without manual checking.

Overview

Instead of manually visiting egov.uscis.gov multiple times per day, the Auto Check Engine runs in the background and checks your case status automatically every few hours. When a change is detected, you receive an instant notification.

How It Works

Step 1: Case Registration

When you add a USCIS receipt number to the app:

• Receipt number is validated (format check)
• Initial status is fetched from USCIS
• Case is registered in Auto Check queue
• Local database record created

Step 2: Background Monitoring

The Auto Check Engine runs as a background service:

• Frequency: Every 2-6 hours (varies by user settings and iOS background limits)
• Method: HTTP request to egov.uscis.gov API
• Data sent: Only your receipt number (public information)
• Data received: Current case status, last updated date, form type

Step 3: Change Detection Algorithm

1. Fetch current status from USCIS
2. Load previous status from local database
3. Compare status text (exact match)
4. If different:
   - Save new status to history
   - Update "last checked" timestamp
   - Trigger notification system
5. If same:
   - Update "last checked" timestamp only
   - No notification

Step 4: History Tracking

Every status change is recorded with:

• Status text
• Timestamp (when USCIS updated it)
• Detection timestamp (when app discovered it)
• Form type
• Service center

Step 5: Notification Delivery

When change detected:

• Push notification sent to device
• In-app badge updated
• Case card highlighted in app
• History tab updated

Technical Architecture

Background Processing

iOS Background Modes:

• Uses BGTaskScheduler for efficient background refresh
• Respects iOS battery optimization
• Adapts frequency based on device conditions

Network Efficiency:

• Lightweight API calls (typically <5KB)
• Concurrent requests for multiple cases
• Automatic retry on network failure
• Exponential backoff if USCIS server issues

Data Storage

Local Database (SQLite):

• Encrypted case receipt numbers
• Complete status history
• Last check timestamps
• User preferences

iCloud Sync (Optional):

• Backup of case list
• Sync across user's iOS devices
• End-to-end encrypted

Check Frequency Explained

Why Not Real-Time?

USCIS does not provide real-time webhooks or APIs. The only way to check status is by querying their website periodically.

Why Every 2-6 Hours?

Balance between:

• ✅ Timeliness: Catch updates within a few hours
• ✅ Battery life: Not drain phone battery
• ✅ Server load: Respectful to USCIS servers
• ✅ iOS limits: Background tasks have restrictions

Reality check: USCIS typically updates cases during business hours (9 AM - 6 PM EST), so checking every 4 hours is sufficient.

Check Frequency Tiers

What Gets Checked

USCIS Case Status Elements:

• Status title (e.g., "Case Approved", "Case Received")
• Status description (detailed text)
• Last updated date
• Form type (I-130, I-485, etc.)
• Service center location

What does NOT get checked:

• ❌ Your USCIS online account details (we don't have access)
• ❌ Your email from USCIS
• ❌ Internal USCIS systems
• ❌ Non-public information

Notification Logic

When Notifications Are Sent

Trigger conditions:

• Status text changed
• OR Status description changed
• OR Last updated date advanced

Smart Filtering

To avoid false positives:

• Ignore whitespace changes
• Ignore trivial wording changes
• Debounce rapid changes (only notify once)
• Respect user's quiet hours

Notification Content

Example notification:

📬 Case Status Update
IOE0123456789

Old: Case Was Received
New: Case Was Approved

Tap to view details

Reliability & Error Handling

Network Failures

If check fails due to network:

• Automatic retry after 15 minutes
• Max 3 retries before waiting for next cycle
• User sees "last checked" timestamp

USCIS Server Issues

If USCIS website is down:

• App shows "Unable to connect to USCIS"
• Continues retrying on schedule
• No false notifications

Invalid Receipt Numbers

If receipt number becomes invalid:

• App shows warning
• Continues checking (may be temporary USCIS issue)
• User can manually verify

Privacy & Security

What We Send to USCIS

• Your receipt number (public information anyone can check)
• No personal information
• No authentication credentials

Data Stored Locally

• Receipt numbers (encrypted at rest)
• Status history (encrypted)
• Timestamps
• User preferences

Data NOT Stored

• Your name or personal details
• USCIS login credentials (we never ask for these)
• Any documents or forms

Battery Impact

Optimization Techniques

• Uses iOS Background App Refresh (energy-efficient)
• Batches multiple case checks together
• Only network activity every few hours
• CPU usage <1% during checks

User Control

You can:

• Adjust check frequency
• Disable auto-check for specific cases
• Enable/disable completely
• Use manual check only

Limitations

iOS Background Restrictions

Apple's limitations:

• Background tasks may be delayed if battery low
• Low Power Mode reduces frequency
• iOS may suspend background refresh if not used

Recommendation: Open app occasionally to keep background refresh active

USCIS Update Timing

Even if we check every 2 hours, there's inherent delay:

• USCIS updates case (unknown exact time)
• Our app checks 0-2 hours later
• Notification sent
• Total delay: 0-2 hours after USCIS update

This is still much better than checking manually once per day!

Comparison: Manual vs Auto

Technical Specifications

API Endpoint: https://egov.uscis.gov/casestatus/mycasestatus.do

Method: POST with form data

Response: HTML parsing (USCIS doesn't provide JSON API)

Timeout: 30 seconds

User-Agent: CaseTracker Auto iOS/3.0

Learn More

• USCIS Tracking Overview
• Notification Settings
• Data Sources
• Privacy & Security
• FAQ: Check Frequency