58.9 Session Tracking Improvements

Documentation for Sessions

Session Tracking Improvements (v8.5)

Session: 58.9 Date: 2026-01-22 Author: AI Architecture Agent

Problem Statement

The MCP session tracking system had critical bugs causing:

SubSessionNumber precision loss - 54.10 became 54.1 due to JavaScript's parseFloat() behavior
Missing session manifests - Sessions 55-58 were never created because updateSessionManifest() only updated existing files
history.json desync - New sessions weren't added to the sessions[] array
Poor schema readability - Decisions at root level, subSessions array separate

Root Cause Analysis

Bug 1: parseFloat Precision Loss

// THE BUG
parseFloat("54.10") === 54.1  // TRUE - loses trailing zero!

This caused:

subSessionNumber: 54.1 when sessionID: "editor2-54.10"
Incorrect ordering of subSessions
Confusion in tracking

Bug 2: Missing Auto-Creation

// BEFORE (broken)
if (fs.existsSync(manifestPath)) {
  // Updates existing... ✅
} else {
  console.error(`⚠️ Session manifest not found`);
  // NOTHING CREATES IT! ❌
}

Solution Implemented (v8.5)

1. Integer-Based Decimal Tracking

Added _subDecimal field to store the integer decimal part:

{
  "sessionNumber": 54,
  "subSessionNumber": 54.10,
  "_subDecimal": 10,
  "sessionID": "editor2-54.10"
}

The _subDecimal field is the authoritative source for the decimal part.

2. Auto-Creation of Session Manifests

updateSessionManifest() now creates manifests if they don't exist:

if (!fs.existsSync(manifestPath)) {
  console.error(`📝 Creating new session manifest: session-${sessionNumber}.json`);
  manifest = {
    schemaVersion: '8.5',
    workspace,
    session: sessionNumber,
    // ... defaults
  };
}

3. Session Repair Script

Created tools/scripts/database/session-repair.js to:

Create missing session manifests
Add _subDecimal to existing manifests
Sync history.json with activeSessions
Create missing docs directories

Usage:

node tools/scripts/database/session-repair.js --dry-run  # Preview
node tools/scripts/database/session-repair.js            # Apply

Improved Schema (v8.5)

Session Manifest Structure

{
  "schemaVersion": "8.5",
  "workspace": "editor2",
  "session": 58,
  "sessionNumber": 58,
  "title": "Description of the session",
  "status": "active",
  "startedAt": "2026-01-22T16:38:35.573Z",
  "lastUpdatedAt": "2026-01-22T17:49:13.252Z",
  
  // v8.5: Integer decimal tracking
  "subSessionNumber": 58.10,
  "_subDecimal": 10,
  "sessionID": "editor2-58.10",
  
  // Ordered lists
  "sessionIDs": ["editor2-58.1", "editor2-58.2", ..., "editor2-58.10"],
  
  "subSessions": [
    {
      "subSessionNumber": 58.1,
      "_subDecimal": 1,
      "sessionID": "editor2-58.1",
      "platform": "cursor",
      "focus": "Initial setup",
      "startedAt": "2026-01-22T10:00:00.000Z",
      "status": "complete",
      "decisionsLogged": 3
    },
    // ... more subSessions, sorted by _subDecimal
  ],
  
  "decisions": [
    // All decisions for this session
  ]
}

Key Changes

Field	Purpose	Type
`_subDecimal`	Integer decimal for accurate tracking	number
`subSessionNumber`	Full float value (may lose precision)	number
`sessionID`	String format, authoritative source	string

JSONL Recommendation

Current State

Session manifests are single JSON files
Large sessions (like 54 with 13 decisions) grow linearly
Editing requires full file read/write

Recommended Future State

For sessions with 50+ decisions, consider JSONL format:

sessions/sessions-history/editor2/session-54/
  ├── manifest.json           # Session metadata
  ├── decisions.jsonl         # Append-only decisions log
  └── subSessions.jsonl       # SubSession records

decisions.jsonl format:

{"id":"dev_123","timestamp":"2026-01-22T10:00:00Z","type":"architecture","subSession":54.1,"question":"...","chosen":"..."}
{"id":"dev_124","timestamp":"2026-01-22T10:30:00Z","type":"implementation","subSession":54.2,"question":"...","chosen":"..."}

Benefits of JSONL

Append-only writes - No need to read/rewrite entire file
Streaming reads - Process one decision at a time
Memory efficient - Don't load all decisions into memory
Git-friendly - Easier to see individual decision diffs
Compression-friendly - Gzip works great on JSONL

Implementation Phases

Phase 1 (Done): Fix tracking accuracy with _subDecimal
Phase 2 (Future): Migrate large sessions to JSONL format
Phase 3 (Future): Add JSONL streaming support to MCP tools

Files Modified

MCP/mcp-gograb-ai/src/storage/docs-data-integration.ts - Core tracking fixes
MCP/mcp-gograb-ai/src/tools/chat-context.ts - Integer decimal support
tools/scripts/database/session-repair.js - New repair script
sessions/sessions-history/editor2/session-*.json - Added _subDecimal

Testing

After changes, verify:

# Check current session info
node -e "import('./MCP/mcp-gograb-ai/src/storage/docs-data-integration.js').then(m => console.log(m.getCurrentSessionInfo()))"

# Run repair script in dry-run mode
node tools/scripts/database/session-repair.js --dry-run

# Check a specific manifest
cat sessions/sessions-history/editor2/session-58.json | jq '._subDecimal, .subSessionNumber, .sessionID'

MongoDB Compatibility

The backend schema already supports:

subSessionNumber (float)
sessionID (string)
subSessions[] array

The _subDecimal field is for local tracking only and doesn't need MongoDB schema changes.

Conclusion

The v8.5 changes fix the critical tracking bugs while maintaining backward compatibility. The JSONL recommendation is for future consideration when sessions grow larger (50+ decisions).