# Track Specification: Session Insights & Efficiency Scores (session_insights_20260306)

## Overview
Token usage over time, cost projections, session summary with efficiency scores.

## Current State Audit

### Already Implemented
- **`session_logger.py`**: Logs comms, tool calls, API hooks
- **`ai_client.get_comms_log()`**: Returns API interaction history
- **`cost_tracker.estimate_cost()`**: Cost calculation

### Gaps to Fill
- No token timeline visualization
- No cost projection
- No efficiency score calculation

## Functional Requirements
- Token usage graph over session
- Cost projection based on burn rate
- Efficiency score (tokens per useful change)
- Session summary text

## Key Integration Points
| File | Purpose |
|-----|---------|
| `src/session_logger.py` | Read session data |
| `src/gui_2.py` | Timeline rendering |

## Acceptance Criteria
- [ ] Token timeline renders
- [ ] Cost projection calculated
- [ ] Efficiency score shown
- [ ] Summary displays key metrics
- [ ] 1-space indentation