feat: per-event project attribution for session tracking

[sebastianbreguel]

Summary

• Adds per-event project attribution to avoid pinning all session activity to startup directory
• Each event gets project_dir, attribution_source, and attribution_confidence (0-1)
• Auto-migration for existing DBs
• Insight server aggregates analytics by project with weighted confidence

Problem

When users switch projects mid-session, all events were attributed to the initial directory. This corrupted spending/activity data per project.

Solution

New project-attribution.ts module with heuristics:

• workspace_root (0.98) > cwd_event (0.9) > input_cwd (0.88) > session_origin (0.82) > last_seen (0.76) > event_path (0.7)

Confidence propagates through session - high-confidence attributions inform subsequent events.

Test plan

• Unit tests pass (188 session tests)
• Manual test: file_read gets 0.88 confidence, user_prompt gets 0.45
• Migration works on existing DBs
• Bundles rebuilt and verified

[sebastianbreguel]

Before vs After: Per-Event Project Attribution

┌─────────────────────────────────────────────────────────────────────────────┐
│                              BEFORE                                         │
├─────────────────────────────────────────────────────────────────────────────┤
│                                                                             │
│   Session start: ~/projects/                                                │
│                                                                             │
│   ┌──────────────────────────────────────────────────────────────────┐     │
│   │                    SESSION EVENTS                                 │     │
│   ├──────────────────────────────────────────────────────────────────┤     │
│   │  Event 1: edit app-a/src/main.ts    → project: ~/projects/       │     │
│   │  Event 2: edit app-a/src/utils.ts   → project: ~/projects/       │     │
│   │  Event 3: edit app-b/lib/api.ts     → project: ~/projects/       │     │
│   │  Event 4: edit app-b/lib/db.ts      → project: ~/projects/       │     │
│   │  Event 5: edit app-a/test/foo.ts    → project: ~/projects/       │     │
│   └──────────────────────────────────────────────────────────────────┘     │
│                                                                             │
│   Insight Dashboard:                                                        │
│   ┌────────────────────────────┐                                           │
│   │  ~/projects/  ████████ 45m │   ← Everything lumped together            │
│   └────────────────────────────┘                                           │
│                                                                             │
└─────────────────────────────────────────────────────────────────────────────┘


┌─────────────────────────────────────────────────────────────────────────────┐
│                               AFTER                                         │
├─────────────────────────────────────────────────────────────────────────────┤
│                                                                             │
│   Session start: ~/projects/                                                │
│                                                                             │
│   ┌──────────────────────────────────────────────────────────────────┐     │
│   │                    SESSION EVENTS                                 │     │
│   ├──────────────────────────────────────────────────────────────────┤     │
│   │  Event 1: edit app-a/src/main.ts                                  │     │
│   │           → project: app-a  (source: file_path, conf: 0.95)       │     │
│   │  Event 2: edit app-a/src/utils.ts                                 │     │
│   │           → project: app-a  (source: file_path, conf: 0.95)       │     │
│   │  Event 3: edit app-b/lib/api.ts                                   │     │
│   │           → project: app-b  (source: git, conf: 1.0)              │     │
│   │  Event 4: edit app-b/lib/db.ts                                    │     │
│   │           → project: app-b  (source: git, conf: 1.0)              │     │
│   │  Event 5: edit app-a/test/foo.ts                                  │     │
│   │           → project: app-a  (source: file_path, conf: 0.95)       │     │
│   └──────────────────────────────────────────────────────────────────┘     │
│                                                                             │
│   Insight Dashboard:                                                        │
│   ┌────────────────────────────┐                                           │
│   │  app-a  ██████████████ 30m │   ← Per-project breakdown                 │
│   │  app-b  ████████     15m   │                                           │
│   └────────────────────────────┘                                           │
│                                                                             │
└─────────────────────────────────────────────────────────────────────────────┘

Key change: Attribution happens per-event, not per-session. Each tool call analyzed → real project detected → tracked separately.

[mksglu]

Code Review: per-event project attribution

The feature addresses a real problem — monorepo/multi-project sessions crediting all events to the startup project_dir. DB migration is clean, core attribution logic is well-structured, and 43 unit tests is solid coverage. Good work overall.

Blockers (must fix before merge)

1. DRY violation — 7 hook files with identical attribution block

The same ~12 lines are copy-pasted into codex/posttooluse, cursor/posttooluse, kiro/posttooluse, vscode-copilot/posttooluse, gemini-cli/posttooluse, posttooluse.mjs, and userpromptsubmit.mjs:

const stats = db.getSessionStats(sessionId);
const lastProject = db.getLatestAttributedProjectDir(sessionId);
const attributions = resolveProjectAttributions(events, { ... });

Extract this into a shared helper in session-loaders.mjs (e.g., resolveAndInsertWithAttribution(db, sessionId, events, input)). One source of truth, one place to update.

2. Magic confidence numbers need named constants

The values 0.98, 0.9, 0.88, 0.82, 0.76, 0.7, 0.45, 0.4, 0.35 appear inline with no explanation. Define them as named constants with a brief rationale:

const CONFIDENCE = {
  WORKSPACE_ROOT: 0.98,   // explicit workspace config — highest signal
  CWD_EVENT: 0.9,         // user navigated here intentionally
  INPUT_CWD: 0.88,        // hook payload cwd — reliable but implicit
  SESSION_ORIGIN: 0.82,   // session startup dir
  LAST_SEEN: 0.76,        // carry-forward from previous event
  EVENT_PATH: 0.7,        // inferred from file path prefix
  // ... fallbacks
} as const;

3. Squash commits

18 commits → 1-3 commits for a clean history.

Missing: Insight UI

The backend API (insight/server.mjs) now queries session_events.project_dir with weighted aggregation — but the Insight dashboard UI (React components in insight/src/) is not updated to display per-project breakdowns. The data flows to the API but there's no way for users to see it. Is this intentional (API-first, UI follow-up) or an oversight?

Test gaps (nice-to-have, not blockers)

• No integration test for the full hook → extract → attribution → DB → insight query pipeline
• No test for the hasColumn() fallback path in insight/server.mjs (221 new lines, zero test coverage)
• Non-path event types (mcp, user_prompt) fallback to low confidence but aren't tested

Summary

Aspect	Grade
Problem solved	✅ Real need
DB migration	✅ Clean, backward compatible
Core logic	✅ Pure functions, well-tested
Performance	✅ Negligible overhead
DRY / code quality	❌ 7-file copy-paste
Constants	❌ Magic numbers
Insight UI	❌ Not updated

Looking forward to the next iteration.

[mksglu]

Merged! We'll follow up with fixes for the DRY violation, magic numbers, and Insight UI on next.

[mksglu]

Follow-up fixes shipped on next

All three blockers from the review are resolved:

Aspect	Before	After
DRY / code quality	❌ 7-file copy-paste	✅ attributeAndInsertEvents() shared helper in session-loaders.mjs (-25 lines)
Constants	❌ Magic numbers	✅ ATTRIBUTION_CONFIDENCE named constants with JSDoc rationale
Insight UI	❌ Not updated	✅ Match Quality labels (Strong/Fair/Weak), thresholds aligned (≥80/≥55/<55), WCAG accessible icons (✓/~/!)

Additional UX improvements:

• "Confidence: 72%" jargon → "Match Quality: Strong"
• "3s · 42e" → "3 sessions · 42 events"
• Scary fallback warning → subtle info with Lightbulb icon
• Developer jargon removed from user-facing text

Commits: 79e0d7e, 773f863, cdce371