---

name: offline-impact-evaluator description: Validate proposed stack against offline requirements. Use after initial stack proposal to identify gaps, assess complexity, and recommend adjustments.

Offline Impact Evaluator

Validate the proposed stack against the offline requirement captured in architecture-refinement. Identify gaps, assess if the solution is over-engineered, and recommend stack adjustments when needed.

Standalone Usage

Can be invoked directly:

• "Does this stack support session-durable offline?"
• "Evaluate offline capability of Next.js + Supabase"
• "Is this architecture over-engineered for transient offline?"

Prerequisites

Requires:

• Architecture brief with offline_requirement.level
• Stack candidates from candidate-generator

Evaluation Process

Step 1: Map Required vs. Actual Capability

Step 2: Assess Each Stack Component

For each candidate, evaluate:

Step 3: Gap Analysis

Identify:

• Under-delivery: Required capability not met
• Over-engineering: Unnecessary complexity for the requirement
• Risk areas: Components with weak offline story

Step 4: Recommendations

If gaps exist:

1. Recommend component swaps or additions
2. Estimate implementation complexity delta
3. Flag if cost re-evaluation is needed

Offline Technology Reference

Output Contract

Copyoffline_impact_evaluation:
  stack_id: "<reference>"
  
  requirement:
    level: "<none|transient|session_durable|strong_offline_first>"
    session_close_behavior: "<loses_data|persists_locally>"
    sync_strategy: "<none|background_sync|manual_sync|crdt>"
  
  assessment:
    actual_level: "<none|transient|session_durable|strong_offline_first>"
    components:
      frontend:
        capability: "<level>"
        notes: "<details>"
      data_layer:
        capability: "<level>"
        technology: "<what provides offline>"
      sync:
        capability: "<level>"
        strategy: "<how sync works>"
  
  gap_analysis:
    has_gap: true|false
    gap_description: "<what's missing>"
    over_engineered: true|false
    over_engineering_notes: "<why it's excessive>"
  
  risks:
    - risk: "<risk description>"
      severity: "<low|medium|high>"
      mitigation: "<how to address>"
  
  recommendations:
    - action: "<what to change>"
      component: "<which component>"
      impact:
        cost: "<increase|decrease|same>"
        complexity: "<increase|decrease|same>"
        timeline: "<increase|decrease|same>"
  
  verdict:
    stack_viable: true|false
    requires_stack_change: true|false
    requires_cost_reevaluation: true|false

Example: Gap Analysis

Copyoffline_impact_evaluation:
  stack_id: "next-vercel-supabase"
  
  requirement:
    level: "session_durable"
    session_close_behavior: "persists_locally"
    sync_strategy: "background_sync"
  
  assessment:
    actual_level: "transient"
    components:
      frontend:
        capability: "transient"
        notes: "No service worker configured by default"
      data_layer:
        capability: "none"
        technology: "Server-side only"
      sync:
        capability: "none"
        strategy: "N/A"
  
  gap_analysis:
    has_gap: true
    gap_description: "Stack lacks local persistence and background sync"
    over_engineered: false
  
  risks:
    - risk: "Data loss on network interruption"
      severity: "high"
      mitigation: "Add IndexedDB layer with sync"
  
  recommendations:
    - action: "Add @tanstack/query with offline persistence"
      component: "data_layer"
      impact:
        cost: "same"
        complexity: "increase"
        timeline: "increase"
    - action: "Implement service worker for caching"
      component: "frontend"
      impact:
        cost: "same"
        complexity: "increase"
        timeline: "increase"
  
  verdict:
    stack_viable: true
    requires_stack_change: false
    requires_cost_reevaluation: false

Integration Points

• Invoked by: stack-evaluation (after candidate-generator)
• May trigger: Cost re-evaluation if requires_cost_reevaluation: true
• Feeds into: implementation-plan (offline phase planning)