Version: 2.0 | Status: Active | Last Updated: January 2026
Change Log
| Version | Date | Changes |
|---|
| 2.0 | Jan 2026 | Converted to business-focused format with measurable outcomes and success metrics |
| 1.0 | Initial | Technical implementation documentation |
1. Overview
1.1 Purpose
The Google APIs Integration provides address autocomplete, distance calculations, and calendar synchronization capabilities that streamline location handling, enable accurate delivery pricing, and keep staff schedules synchronized across platforms.
1.2 Problem Statement
Rental operators and customers face significant friction without Google integrations:
- Manual address entry causes 15-20% error rates and adds 2-3 minutes per booking
- Inconsistent address formats create operational confusion and failed deliveries
- Manual distance calculations for delivery pricing lead to revenue leakage (undercharging) or customer complaints (overcharging)
- Staff miss reservations when switching between booking system and personal calendars
- Multi-language address support is difficult, limiting international market expansion
1.3 Business Value
| Value Claim | Measurable Outcome | Baseline | Target | Timeframe |
|---|
| Faster Address Entry | Reduce address input time per booking | 2-3 minutes manual entry | <30 seconds with autocomplete (80%+ reduction) | Within 30 days |
| Improved Data Quality | Reduce address-related booking errors | ~15-20% manual entry errors | <2% with autocomplete | Within 60 days |
| Accurate Delivery Pricing | Eliminate manual distance calculation discrepancies | ±20% pricing variance | <2% variance from actual | Within 30 days |
| API Cost Efficiency | Reduce Google API costs through caching | 100% API calls for repeated routes | 90%+ cache hit rate | Within 90 days |
| Staff Visibility | Reduce missed reservations due to calendar gaps | Manual calendar checking | Automatic sync (zero manual updates) | Within 30 days |
| Booking Conversion | Improve checkout completion with familiar address UI | Current checkout abandonment rate | 5-10% improvement in address step completion | Within 90 days |
1.4 Target Users
| Role | Primary Use Case | Business Impact |
|---|
| Admin | Integration configuration, cost monitoring | Manages API spend, ensures compliance |
| Operator | Address autocomplete, delivery pricing | Faster booking creation, accurate quotes |
| Partner | Location setup, optional calendar sync | Efficient fleet management |
| Customer | Address selection during booking | Reduced friction, fewer errors |
| Widget Users | Embedded address autocomplete | Consistent experience across channels |
2. Success Metrics
| Category | Metric | Definition | Baseline | Target | Measurement Method |
|---|
| Efficiency | Address Entry Time | Average time to complete address field | 2-3 min (manual) | <30 sec | User session analytics |
| Quality | Address Error Rate | % bookings with address-related issues | 15-20% (estimated) | <2% | Support ticket analysis |
| Revenue | Delivery Pricing Accuracy | Variance between quoted and actual delivery cost | ±20% | <2% | Order audit sampling |
| Cost | API Cache Hit Rate | % distance requests served from cache | 0% (no caching) | >90% | Database query logs |
| Cost | Monthly API Spend | Google Maps Platform charges | Baseline month 1 | 60% reduction by month 3 | Google Cloud billing |
| Adoption | Calendar Sync Activation | % eligible users with calendar connected | 0% | >50% operators | User settings database |
| Satisfaction | Address Autocomplete NPS | User satisfaction with address input | Not measured | >8/10 | In-app survey |
Measurement Framework:
- Baseline Period: 30-day pre-implementation measurement
- Sources: Support tickets, session analytics, API billing, user surveys
- Review Cadence: Weekly for first month, monthly thereafter
3. User Stories
Address Autocomplete (P0 - Critical)
| Priority | User Story | Acceptance Criteria |
|---|
| P0 | As an operator creating a reservation, I can search for addresses with autocomplete so that I quickly select accurate locations | Suggestions appear within 500ms of typing 3+ characters; selected address populates all fields |
| P0 | As a customer booking a vehicle, I can select my address from suggestions so that I avoid typing errors | Mobile-friendly dropdown; address validated before checkout |
| P1 | As an operator, I can select from saved office locations so that I reuse frequent addresses | Office addresses appear in suggestions; labeled distinctly |
| P1 | As a multilingual operator, I can search addresses in my preferred language | Suggestions match user locale (12 languages supported) |
| P2 | As an operator, I can add custom notes to addresses (apt #, gate code) | Notes persist with address; displayed in booking details |
Distance Calculation (P0 - Critical)
| Priority | User Story | Acceptance Criteria |
|---|
| P0 | As an operator, delivery distance is calculated automatically so that pricing is accurate | Distance displayed within 3 seconds; shown in kilometers |
| P0 | As a billing manager, distance-based fees are calculated correctly | Fee matches distance × rate; visible on invoice |
| P1 | As an admin, I can monitor distance calculation costs | Dashboard shows API calls vs cache hits; monthly spend visible |
Google Calendar Sync (P1 - Important)
| Priority | User Story | Acceptance Criteria |
|---|
| P1 | As an operator, I can sync reservations to Google Calendar | One-click OAuth; reservations appear in calendar within 5 minutes |
| P1 | As an operator, calendar events update when reservations change | Updates sync within 15 minutes; no duplicate events |
| P2 | As an operator, I can customize calendar event content | Settings for deposit, pricing, partner name visibility |
| P2 | As an operator, I can disconnect calendar sync | One-click disconnect; existing events remain in Google Calendar |
4. Functional Requirements
4.1 Address Autocomplete
| ID | Requirement | Business Rationale |
|---|
| FR-01 | System must provide address suggestions within 500ms of user typing 3+ characters | Enables fast, accurate address entry |
| FR-02 | System must support 12 languages for address suggestions (en, es, fr, de, it, pl, lt, nl, cs, pt, zh, ru) | Enables international market expansion |
| FR-03 | System must include company office addresses in autocomplete suggestions | Reduces repetitive data entry for frequent locations |
| FR-04 | System must return structured address components (street, city, postal code, country, coordinates) | Enables reliable reporting, delivery routing, and mapping |
| FR-05 | System must display country flags for visual location identification | Improves accuracy for cross-border operations |
| FR-06 | System must support custom address notes (apartment, gate codes) | Captures delivery-critical information |
4.2 Distance Calculation
| ID | Requirement | Business Rationale |
|---|
| FR-07 | System must calculate driving distance between two locations in kilometers | Enables accurate delivery pricing |
| FR-08 | System must cache distance calculations indefinitely | Reduces API costs by 90%+ for repeated routes |
| FR-09 | System must return results within 3 seconds or fail gracefully | Ensures responsive user experience |
| FR-10 | System must prevent duplicate API calls for identical concurrent requests | Prevents unnecessary API spend |
| FR-11 | System must select minimum distance when multiple routes exist | Ensures customers receive fair pricing |
| FR-12 | System must return zero distance when origin equals destination | Handles same-location scenarios correctly |
4.3 Calendar Synchronization
| ID | Requirement | Business Rationale |
|---|
| FR-13 | System must provide one-click Google Calendar connection via OAuth | Minimizes setup friction |
| FR-14 | System must create calendar events for all reservations within 5 minutes | Keeps staff schedules current |
| FR-15 | System must update calendar events when reservations are modified | Maintains calendar accuracy |
| FR-16 | System must prevent duplicate calendar events for the same reservation | Avoids staff confusion |
| FR-17 | System must allow customization of event content (deposit, pricing visibility) | Respects user privacy preferences |
| FR-18 | System must support calendar disconnection without deleting existing events | Provides clean off-boarding |
| FR-19 | System must limit calendar sync to Admin, Operator, and Partner roles | Maintains appropriate access control |
| ID | Requirement | Business Rationale |
|---|
| FR-20 | System must log all API failures with context for troubleshooting | Enables rapid issue resolution |
| FR-21 | System must provide fallback behavior when APIs are unavailable | Prevents booking workflow interruption |
| FR-22 | System must process calendar sync jobs with retry capability | Ensures eventual consistency |
5. Acceptance Criteria
AC-01: Address Autocomplete
- Given I am entering an address in any booking flow
- When I type “123 Main” (3+ characters)
- Then suggestions appear within 500ms
- And I can select an address to populate all fields including coordinates
- And my company’s office addresses appear if they match my search
AC-02: Multi-Language Support
- Given my account language is Italian
- When I search for “Via Roma”
- Then suggestions appear in Italian with Italian formatting conventions
AC-03: Distance Calculation with Caching
- Given I need delivery pricing from Rome to Milan
- When the distance is calculated for the first time
- Then the result is returned within 3 seconds and cached
- When the same route is requested again (by any user)
- Then the cached value is returned instantly with zero API cost
AC-04: Concurrent Request Handling
- Given 100 simultaneous requests for the same route
- When all requests arrive within the same second
- Then only 1 API call is made
- And all 100 requesters receive the same result
AC-05: Calendar Connection
- Given I am an operator without calendar sync
- When I click “Connect Google Calendar”
- Then I complete Google OAuth consent
- And a calendar is created/linked
- And all my reservations sync within 5 minutes
AC-06: Calendar Event Updates
- Given I have calendar sync enabled
- When a reservation is created or modified
- Then the calendar event reflects current reservation details
- And no duplicate events exist for the same reservation
AC-07: Calendar Disconnection
- Given I have active calendar sync
- When I click “Disconnect”
- Then future reservations stop syncing
- And existing calendar events remain (not deleted)
AC-08: Error Handling
- Given the Google API is unavailable
- When an address search or distance calculation fails
- Then the error is logged for investigation
- And I see a graceful fallback (manual entry option or retry prompt)
6. Business Rules
Address Processing
- BR-01: Minimum 3 characters required before autocomplete triggers (reduces unnecessary API calls)
- BR-02: 500ms debounce on typing to batch requests (80%+ API call reduction)
- BR-03: Office addresses prioritized in results for frequent-use convenience
- BR-04: Address components extracted: street, number, city, state, postal code, country, coordinates
- BR-05: Custom address notes persist across address re-selection
Distance Calculation
- BR-06: Distances cached indefinitely (locations don’t move)
- BR-07: Cache key uses alphabetically-sorted locations for bidirectional consistency
- BR-08: Concurrent identical requests share single API call result
- BR-09: Sequential API execution (one at a time) to prevent rate limiting
- BR-10: 3-second timeout with graceful failure
Calendar Sync
- BR-11: OAuth requires offline access for refresh token (persistent sync without re-authentication)
- BR-12: Event ID = Reservation ID (prevents duplicates, enables updates)
- BR-13: Only Admin, Operator, and Partner roles can enable calendar sync
- BR-14: Calendar settings control visibility: deposit, pricing, payments, partner name
- BR-15: Disconnection preserves existing events in Google Calendar
Cost Optimization
- BR-16: Request deduplication prevents duplicate API charges
- BR-17: Database caching eliminates repeated route calculations
- BR-18: Field masking requests only required data from Places API
7. Dependencies
Internal Systems
| Dependency | Integration Point | Impact |
|---|
| Order/Reservation System | Calendar sync, delivery addresses | Calendar events reflect reservation data |
| Vehicle Management | Vehicle location addresses | Location accuracy for fleet tracking |
| Office Management | Office addresses in autocomplete | Streamlined address selection |
| Authentication | User roles for calendar access | Access control enforcement |
| GPS Tracking | Coordinates from Places API | Vehicle location mapping |
External Services
| Service | Purpose | Failure Impact |
|---|
| Google Places API | Address autocomplete and details | Manual address entry fallback |
| Google Distance Matrix API | Route distance calculation | Manual distance entry fallback |
| Google Calendar API | Reservation synchronization | Calendar remains out of sync |
| Vercel OIDC | Places API authentication | Places features unavailable |
Infrastructure
| Component | Purpose |
|---|
| PostgreSQL | Distance cache, calendar settings, user tokens |
| Error Tracking (Sentry) | API failure monitoring and alerting |
| Job Queue | Reliable calendar event delivery |
| Scheduled Tasks (QStash) | Periodic calendar synchronization |
8. Non-Functional Requirements
| Category | Requirement | Target |
|---|
| Performance | Address autocomplete response time | <500ms |
| Performance | Distance calculation response time | <3 seconds |
| Performance | Calendar event sync latency | <5 minutes |
| Reliability | API request timeout handling | 3-second timeout with graceful degradation |
| Reliability | Calendar sync job retry | Automatic retry on transient failures |
| Cost | Distance API cache hit rate | >90% |
| Cost | Places API field optimization | Request only required fields |
| Security | OAuth token encryption | Encrypted at rest |
| Security | Service account credentials | Server-side only, never exposed to client |
| Scalability | Concurrent request deduplication | 100+ simultaneous identical requests → 1 API call |
9. Risks & Mitigations
| Risk | Impact | Likelihood | Mitigation |
|---|
| Google API rate limiting | Service degradation | Medium | Sequential execution, request deduplication |
| API cost overruns | Budget impact | Medium | Caching, monitoring dashboard, alerts |
| OAuth token expiration | Calendar sync failure | Low | Automatic refresh token renewal |
| Places API unavailability | Address entry friction | Low | Manual entry fallback, cached office addresses |
| Multi-language data quality | International UX issues | Low | Google’s native localization, user locale detection |
10. Future Considerations
Not in current scope but potential future enhancements:
- Interactive maps for vehicle locations and delivery routes
- Turn-by-turn navigation for couriers
- Nearby pickup location suggestions
- Two-way calendar sync (block availability from external events)
- Real-time traffic-aware delivery pricing
11. Glossary
| Term | Definition |
|---|
| Autocomplete | Suggesting address completions as user types |
| Distance Matrix | Service calculating travel distances between locations |
| OAuth | Authorization framework for third-party calendar access |
| Refresh Token | Long-lived credential for persistent calendar sync |
| Cache Hit Rate | Percentage of requests served from stored data vs API |
| Debouncing | Delaying function execution until input stabilizes |
| Field Masking | Requesting only required data fields to reduce costs |