---
id: P-REINFORCE-WIKI-18722064
category: Unified
confidence_score: 0.95
tags: ['architecture-principles']
last_reinforced: 2026-05-02
---

# Development Log: Second Brain Trace Mode

## Purpose
Make Second Brain usage visible and testable in AI answers.

## Implementation Summary
- Added `src/features/secondBrainTrace.ts`.
- Added trace scoring over active Second Brain Markdown files.
- Added user-facing trace Markdown with usage status, referenced documents, unused documents, and grounding metrics.
- Added debug JSON output when debug mode is enabled.
- Added Trace and Dbg sidebar buttons.
- Connected trace context into `AgentExecutor`.
- Added tests for retrieval, rendering, debug JSON, and no-use cases.

## Changed Files
- `src/features/secondBrainTrace.ts`
- `src/agent.ts`
- `src/sidebarProvider.ts`
- `tests/secondBrainTrace.test.ts`
- `docs/records/ConnectAI/planning/2026-05-02_second-brain-trace-mode.md`
- `docs/records/ConnectAI/development/2026-05-02_second-brain-trace-mode_implementation.md`

## Verification
- `./node_modules/.bin/tsc --noEmit`
- `npm run compile`
- `./node_modules/.bin/jest --runInBand`

## Result
When Trace mode is on, answers can now include:
- 2nd Brain usage status
- Reason for use or non-use
- Referenced note paths and excerpts
- Searched but unused notes
- Retrieval and grounding metrics
- Optional debug JSON

## 🔗 Knowledge Connections
### Related Concepts (Auto-Linked)
* [[Architecture]]
* [[P-Reinforce]]
* [[Principles]]
* [[Purpose]]