Skip to main content

​
Why Site Visit Verification is Critical

In high-ticket real estate sales, site visits represent the most significant leading indicator of future bookings. Brokerages must verify that sales executives actually accompanied prospective buyers to the physical project site, rather than logging fictitious meetings from home or office desks. BrokerOS eliminates fraudulent check-ins through a tamper-resistant GPS selfie verification workflow:
  • The executive must capture a live photo using the in-app camera (gallery uploads are disallowed)
  • Device GPS coordinates are captured at the exact second the shutter triggers
  • The system computes the distance between the agent’s location and the project’s registered coordinates
  • Photos and metadata are uploaded to Vercel Blob and submitted to the manager for validation

​
Step-by-Step Verification Workflow

1

Open Scheduled Site Visit

The sales executive opens an active SiteVisit record on their mobile app and taps Verify Visit.
2

GPS Precision Check

The app requests high-accuracy foreground coordinates using expo-location. The GPS fix must have an accuracy rating within 50 meters. If an agent is in an underground parking lot with a degraded satellite fix, they are instructed to move to an open area.
3

Capture Live Selfie on Site

The camera opens directly inside the application. The executive captures a photo with the project building, sales lounge, or construction gate visible in the background. The app overlays:
  • Live UTC and local timestamp
  • High-precision GPS latitude and longitude
  • Project name and lead identification number
4

Upload to Cloud Storage

The photo is uploaded to Vercel Blob cloud storage via @brokeros/storage. A permanent URL is attached to a new SiteVisitVerification database record.
5

Automated Proximity Calculation

The backend runs the Haversine formula comparing the capture coordinates against the project’s official coordinates registered in the database:
  • If distance is within 500 meters: Marked as VERIFIED.
  • If distance exceeds 500 meters: Flagged as OUT_OF_RANGE for administrative audit.
6

Manager Review & Approval

In the Next.js web application, the Sales Manager inspects the site visit record:
  • Reviews the submitted selfie image
  • Inspects the Google Maps satellite pin showing where the photo was taken vs. the project gate
  • Clicks Approve or Reject (with mandatory rejection reasoning).

​
Database Architecture (SiteVisitVerification)

The verification record is persisted in PostgreSQL using the Prisma schema:

​
Anti-Spoofing Safeguards

BrokerOS enforces three strict anti-spoofing measures:
  1. No Photo Gallery Ingestion: The app interface intentionally disables external gallery or camera roll selection. Only real-time shutter clicks from the active device camera are accepted.
  2. Mock Location Detection: On Android devices, the location engine inspects the isFromMockProvider flag. If mock locations or fake GPS simulation apps are active, the submission is rejected.
  3. Timestamp Integrity Checks: The client timestamp is cross-referenced with server time to ensure employees cannot alter their device clock to fake historical visits.

​
Configurable Project Geofencing Tolerances

Admins can customize geofence tolerances per project in Web Dashboard -> Inventory -> Project Settings: