cortex/docs/milestones/05-daily-journal.md

# Milestone 5: Daily Journal

## Overview

Quick-capture system for daily notes, thoughts, and todos. Every day gets its own node, making it easy to track what happened when.

## Motivation

- Logseq's daily notes are beloved by users
- Low-friction capture encourages consistent use
- Chronological organization aids recall
- Natural integration with auto-capture

## Features

### 5.1 Daily Note Creation

```bash
# Open/create today's journal
cortex journal

# Add to today's journal
cortex journal "Fixed the auth bug"
cortex j "Quick thought"  # Alias

# View specific day
cortex journal --date 2024-01-15
cortex journal --yesterday
```

### 5.2 Quick Capture

Append to today's journal without opening it:

```bash
# Quick capture
cortex capture "Remember to update docs"
cortex c "TODO: refactor auth"  # Alias

# Capture with tags
cortex capture "API rate limiting idea" --tags api,performance

# Capture from clipboard
cortex capture --clipboard
```

### 5.3 Journal Structure

```typescript
interface JournalNode {
  kind: 'memory';
  title: string;           // "Journal: 2024-01-15"
  content: string;         // Markdown with entries
  tags: ['journal', 'daily', '2024-01', '2024'];
  metadata: {
    date: string;          // "2024-01-15"
    entries: JournalEntry[];
  };
}

interface JournalEntry {
  time: string;            // "14:30"
  text: string;
  tags?: string[];
}
```

### 5.4 Journal Linking

Auto-link journals to related nodes:

- Mentioned node IDs → `relates_to` edge
- Mentioned tags → find and link relevant nodes
- Mentioned files → link to indexed components

### 5.5 End-of-Day Summary

Optional AI-generated summary:

```bash
# Generate summary of today
cortex journal --summarize

# Auto-summarize at end of day (cron/scheduled task)
cortex journal --summarize --auto
```

### 5.6 Journal Search

```bash
# Search within journals
cortex journal --search "auth bug"

# List recent journals
cortex journal --list
cortex journal --list --month 2024-01
```

## Implementation

### Journal Service

```typescript
// src/core/journal.ts
export async function getOrCreateJournal(date?: string): Promise<Node> {
  const targetDate = date || formatDate(new Date());
  const title = `Journal: ${targetDate}`;

  // Find existing
  const existing = await findNodeByTitle(title);
  if (existing) return existing;

  // Create new
  return addNode({
    kind: 'memory',
    title,
    content: `# ${targetDate}\n\n`,
    tags: ['journal', 'daily', ...dateTags(targetDate)],
    metadata: { date: targetDate, entries: [] },
  });
}

export async function appendToJournal(text: string, options?: CaptureOptions): Promise<void> {
  const journal = await getOrCreateJournal();
  const time = formatTime(new Date());

  const entry: JournalEntry = {
    time,
    text,
    tags: options?.tags,
  };

  // Append to content
  const newContent = `${journal.content}\n- **${time}** ${text}`;

  // Update metadata
  const entries = [...(journal.metadata.entries || []), entry];

  await updateNode(journal.id, {
    content: newContent,
    metadata: { ...journal.metadata, entries },
  });

  // Auto-link mentioned nodes
  await linkMentionedNodes(journal.id, text);
}
```

### Daily Summary Generator

```typescript
async function generateDailySummary(date: string): Promise<string> {
  const journal = await getOrCreateJournal(date);
  if (!journal.metadata.entries?.length) return '';

  const prompt = `
Summarize this day's journal entries in 2-3 sentences.
Focus on: accomplishments, decisions, blockers.

Entries:
${journal.metadata.entries.map(e => `- ${e.time}: ${e.text}`).join('\n')}

Summary:`;

  return generate(prompt);
}
```

## CLI Commands

| Command | Description |
|---------|-------------|
| `cortex journal` | Open today's journal |
| `cortex journal <text>` | Add entry to today |
| `cortex journal --date <date>` | View/edit specific day |
| `cortex journal --yesterday` | Yesterday's journal |
| `cortex journal --list` | List recent journals |
| `cortex journal --search <query>` | Search journals |
| `cortex journal --summarize` | Generate summary |
| `cortex capture <text>` | Quick capture alias |
| `cortex c <text>` | Even shorter alias |

## MCP Tools

```typescript
memory_journal       // Get/create today's journal
memory_capture       // Quick capture to journal
memory_journal_list  // List recent journals
```

## Integration

### With Auto-Capture (Milestone 2)

Auto-captured conversations link to that day's journal:

```typescript
// In auto-capture hook
const journal = await getOrCreateJournal();
addEdge(capturedNode.id, journal.id, 'relates_to', { reason: 'same-day' });
```

### With Context Injection (Milestone 3)

Recent journal entries included in context:

```typescript
// In context gathering
const recentJournals = await getRecentJournals(3); // Last 3 days
candidates.push(...recentJournals.map(j => ({ node: j, score: 0.6, reason: 'journal' })));
```

## Testing

- [ ] Creates journal node for today
- [ ] Appends entries with timestamps
- [ ] `--date` flag accesses correct day
- [ ] Search finds entries across journals
- [ ] Summary generation works
- [ ] Journal linked to mentioned nodes

## Acceptance Criteria

- [ ] `cortex capture "text"` takes <100ms
- [ ] Journals organized by date
- [ ] Can search across all journals
- [ ] Summary captures key points
- [ ] Integrates with auto-capture
- [ ] MCP tools work correctly

## Estimated Effort

- Journal CRUD: 3 hours
- Quick capture: 2 hours
- Search/list: 2 hours
- Summary generation: 2 hours
- Linking: 2 hours
- CLI polish: 2 hours
- Testing: 2 hours
- **Total: ~15 hours**

## Dependencies

- None (independent milestone)

## References

- [Logseq daily notes](https://docs.logseq.com/#/page/daily%20notes)
- [Obsidian daily notes plugin](https://help.obsidian.md/Plugins/Daily+notes)