diff --git a/src/cli/commands/journal.ts b/src/cli/commands/journal.ts
new file mode 100644
index 0000000..d835bfb
--- /dev/null
+++ b/src/cli/commands/journal.ts
@@ -0,0 +1,160 @@
+import { Command } from 'commander';
+import chalk from 'chalk';
+import {
+  getOrCreateJournal,
+  appendToJournal,
+  listJournals,
+  searchJournals,
+  generateJournalSummary,
+  getJournalByDate,
+  formatDate,
+  getDateFromOffset,
+  JournalMetadata,
+} from '../../core/journal';
+
+export const journalCommand = new Command('journal')
+  .description('Daily journal - quick capture and daily notes')
+  .argument('[text...]', 'Text to add to today\'s journal')
+  .option('-d, --date <date>', 'Specific date (YYYY-MM-DD)')
+  .option('--yesterday', 'Yesterday\'s journal')
+  .option('-l, --list', 'List recent journals')
+  .option('--month <month>', 'Filter by month (YYYY-MM)')
+  .option('-s, --search <query>', 'Search journals')
+  .option('--summarize', 'Generate AI summary')
+  .option('-t, --tags <tags>', 'Tags for the entry (comma-separated)')
+  .action(async (textParts: string[], opts) => {
+    try {
+      // Determine target date
+      let targetDate: string | undefined;
+      if (opts.date) {
+        targetDate = opts.date;
+      } else if (opts.yesterday) {
+        targetDate = getDateFromOffset('yesterday');
+      }
+
+      // List journals
+      if (opts.list) {
+        const journals = listJournals({ month: opts.month, limit: 20 });
+        if (journals.length === 0) {
+          console.log(chalk.yellow('No journals found.'));
+          return;
+        }
+        console.log(chalk.cyan('Recent Journals:\n'));
+        for (const j of journals) {
+          const meta = j.metadata as JournalMetadata;
+          const entryCount = meta.entries?.length || 0;
+          const summaryIndicator = meta.summary ? ' [summarized]' : '';
+          console.log(`  ${chalk.white(meta.date)}  ${chalk.dim(`${entryCount} entries`)}${chalk.green(summaryIndicator)}`);
+        }
+        return;
+      }
+
+      // Search journals
+      if (opts.search) {
+        const results = await searchJournals(opts.search);
+        if (results.length === 0) {
+          console.log(chalk.yellow('No matching journals found.'));
+          return;
+        }
+        console.log(chalk.cyan(`Found ${results.length} journals:\n`));
+        for (const j of results) {
+          const meta = j.metadata as JournalMetadata;
+          console.log(chalk.white(`${meta.date}:`));
+          // Show matching entries
+          const entries = meta.entries?.filter(e =>
+            e.text.toLowerCase().includes(opts.search.toLowerCase())
+          ) || [];
+          for (const e of entries.slice(0, 3)) {
+            console.log(chalk.dim(`  ${e.time}`) + ` ${e.text}`);
+          }
+          if (entries.length > 3) {
+            console.log(chalk.dim(`  ... and ${entries.length - 3} more`));
+          }
+          console.log();
+        }
+        return;
+      }
+
+      // Generate summary
+      if (opts.summarize) {
+        console.log(chalk.cyan('Generating summary...'));
+        const summary = await generateJournalSummary(targetDate);
+        if (!summary) {
+          console.log(chalk.yellow('No entries to summarize.'));
+          return;
+        }
+        console.log();
+        console.log(chalk.green('Summary:'));
+        console.log(summary);
+        return;
+      }
+
+      // Add entry or view journal
+      const text = textParts.join(' ').trim();
+
+      if (text) {
+        // Add entry
+        const tags = opts.tags?.split(',').map((t: string) => t.trim());
+        const { journal, entry } = await appendToJournal(text, { tags, date: targetDate });
+        const meta = journal.metadata as JournalMetadata;
+        console.log(chalk.green(`✓ Added to ${meta.date}`));
+        console.log(chalk.dim(`  ${entry.time}`) + ` ${text}`);
+      } else {
+        // View journal
+        const journal = await getOrCreateJournal(targetDate);
+        const meta = journal.metadata as JournalMetadata;
+        console.log(chalk.cyan(`Journal: ${meta.date}`));
+        console.log(chalk.dim(`ID: ${journal.id.slice(0, 8)}`));
+        console.log();
+
+        if (!meta.entries?.length) {
+          console.log(chalk.dim('No entries yet. Add one with: cortex journal "your text"'));
+        } else {
+          for (const entry of meta.entries) {
+            const tagStr = entry.tags?.length ? chalk.blue(` [${entry.tags.join(', ')}]`) : '';
+            console.log(chalk.dim(`${entry.time}`) + tagStr + ` ${entry.text}`);
+          }
+        }
+
+        if (meta.summary) {
+          console.log();
+          console.log(chalk.green('Summary:'));
+          console.log(meta.summary);
+        }
+      }
+    } catch (err: any) {
+      console.error(chalk.red(`Error: ${err.message}`));
+      process.exit(1);
+    }
+  });
+
+// Alias: cortex j
+export const journalAliasCommand = new Command('j')
+  .description('Alias for journal command')
+  .argument('[text...]', 'Text to add')
+  .option('-t, --tags <tags>', 'Tags (comma-separated)')
+  .action(async (textParts: string[], opts) => {
+    const text = textParts.join(' ').trim();
+    if (!text) {
+      const journal = await getOrCreateJournal();
+      const meta = journal.metadata as JournalMetadata;
+      console.log(chalk.cyan(`Journal: ${meta.date} (${meta.entries?.length || 0} entries)`));
+      return;
+    }
+    const tags = opts.tags?.split(',').map((t: string) => t.trim());
+    const { journal, entry } = await appendToJournal(text, { tags });
+    const meta = journal.metadata as JournalMetadata;
+    console.log(chalk.green(`✓ ${meta.date} ${entry.time}`) + ` ${text}`);
+  });
+
+// Quick capture: cortex c
+export const quickCaptureCommand = new Command('c')
+  .description('Quick capture to today\'s journal')
+  .argument('<text...>', 'Text to capture')
+  .option('-t, --tags <tags>', 'Tags (comma-separated)')
+  .action(async (textParts: string[], opts) => {
+    const text = textParts.join(' ').trim();
+    const tags = opts.tags?.split(',').map((t: string) => t.trim());
+    const { entry } = await appendToJournal(text, { tags });
+    console.log(chalk.green(`✓ ${entry.time}`) + ` ${text}`);
+  });
diff --git a/src/cli/index.ts b/src/cli/index.ts
index 27602a8..a802482 100644
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -17,6 +17,7 @@ import { restoreCommand } from './commands/restore';
 import { captureCommand, captureHookCommand, configCommand } from './commands/capture';
 import { contextCommand, contextHookCommand } from './commands/context';
 import { indexCommand } from './commands/index-cmd';
+import { journalCommand, journalAliasCommand, quickCaptureCommand } from './commands/journal';
 import { closeDb } from '../core/db';
 
 const program = new Command();
@@ -46,6 +47,9 @@ program.addCommand(contextCommand);
 program.addCommand(contextHookCommand);
 program.addCommand(configCommand);
 program.addCommand(indexCommand);
+program.addCommand(journalCommand);
+program.addCommand(journalAliasCommand);
+program.addCommand(quickCaptureCommand);
 
 program.hook('postAction', () => {
   closeDb();
diff --git a/src/core/journal.ts b/src/core/journal.ts
new file mode 100644
index 0000000..8ed39b3
--- /dev/null
+++ b/src/core/journal.ts
@@ -0,0 +1,222 @@
+import { addNode, updateNode, listNodes, getNode, addEdge } from './store';
+import { Node } from '../types';
+import { generate, isGenAvailable } from './search/ollamaGen';
+
+export interface JournalEntry {
+  time: string;
+  text: string;
+  tags?: string[];
+}
+
+export interface JournalMetadata {
+  date: string;
+  entries: JournalEntry[];
+  summary?: string;
+}
+
+function formatDate(date: Date): string {
+  return date.toISOString().split('T')[0];
+}
+
+function formatTime(date: Date): string {
+  return date.toTimeString().slice(0, 5);
+}
+
+function dateTags(dateStr: string): string[] {
+  const [year, month] = dateStr.split('-');
+  return [year, `${year}-${month}`];
+}
+
+function getDateFromOffset(offset: string): string {
+  const now = new Date();
+  if (offset === 'yesterday') {
+    now.setDate(now.getDate() - 1);
+  } else if (offset === 'tomorrow') {
+    now.setDate(now.getDate() + 1);
+  } else if (offset.match(/^-\d+$/)) {
+    now.setDate(now.getDate() + parseInt(offset));
+  }
+  return formatDate(now);
+}
+
+export async function getOrCreateJournal(date?: string): Promise<Node> {
+  const targetDate = date || formatDate(new Date());
+  const title = `Journal: ${targetDate}`;
+
+  // Find existing journal for this date
+  const existing = listNodes({ kind: 'memory', tags: ['journal'] })
+    .find(n => n.title === title);
+
+  if (existing) {
+    return existing;
+  }
+
+  // Create new journal
+  const dayName = new Date(targetDate).toLocaleDateString('en-US', { weekday: 'long' });
+  return addNode({
+    kind: 'memory',
+    title,
+    content: `# ${dayName}, ${targetDate}\n\n`,
+    tags: ['journal', 'daily', ...dateTags(targetDate)],
+    metadata: {
+      date: targetDate,
+      entries: [],
+    },
+  });
+}
+
+export async function appendToJournal(
+  text: string,
+  options?: { tags?: string[]; date?: string }
+): Promise<{ journal: Node; entry: JournalEntry }> {
+  const journal = await getOrCreateJournal(options?.date);
+  const time = formatTime(new Date());
+
+  const entry: JournalEntry = {
+    time,
+    text,
+    tags: options?.tags,
+  };
+
+  // Format entry line
+  const tagStr = options?.tags?.length ? ` \`${options.tags.join(', ')}\`` : '';
+  const entryLine = `- **${time}**${tagStr} ${text}`;
+
+  // Append to content
+  const newContent = journal.content.trimEnd() + '\n' + entryLine + '\n';
+
+  // Update metadata
+  const metadata = journal.metadata as JournalMetadata;
+  const entries = [...(metadata.entries || []), entry];
+
+  const updated = await updateNode(journal.id, {
+    content: newContent,
+    metadata: { ...metadata, entries },
+  });
+
+  // Auto-link mentioned nodes (if text contains node IDs or @mentions)
+  await linkMentionedNodes(journal.id, text);
+
+  return { journal: updated!, entry };
+}
+
+async function linkMentionedNodes(journalId: string, text: string): Promise<void> {
+  // Find UUID-like patterns (node IDs)
+  const uuidPattern = /\b([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\b/gi;
+  const matches = text.match(uuidPattern);
+
+  if (matches) {
+    for (const id of matches) {
+      const node = getNode(id);
+      if (node && node.id !== journalId) {
+        try {
+          addEdge(journalId, node.id, 'relates_to', { reason: 'mentioned' });
+        } catch {
+          // Edge might already exist
+        }
+      }
+    }
+  }
+
+  // Find #hashtag patterns
+  const hashtagPattern = /#(\w+)/g;
+  const hashtags = [...text.matchAll(hashtagPattern)].map(m => m[1]);
+
+  if (hashtags.length) {
+    // Find nodes with these tags
+    const related = listNodes({ tags: hashtags, limit: 5 });
+    for (const node of related) {
+      if (node.id !== journalId) {
+        try {
+          addEdge(journalId, node.id, 'relates_to', { reason: 'hashtag' });
+        } catch {
+          // Edge might already exist
+        }
+      }
+    }
+  }
+}
+
+export function listJournals(options?: {
+  limit?: number;
+  month?: string;
+  year?: string;
+}): Node[] {
+  let tags = ['journal'];
+  if (options?.month) tags.push(options.month);
+  else if (options?.year) tags.push(options.year);
+
+  return listNodes({
+    kind: 'memory',
+    tags,
+    limit: options?.limit || 30,
+  }).sort((a, b) => {
+    // Sort by date descending
+    const dateA = (a.metadata as JournalMetadata)?.date || '';
+    const dateB = (b.metadata as JournalMetadata)?.date || '';
+    return dateB.localeCompare(dateA);
+  });
+}
+
+export async function searchJournals(query: string, limit: number = 10): Promise<Node[]> {
+  const journals = listNodes({ kind: 'memory', tags: ['journal'], limit: 100 });
+  const lowerQuery = query.toLowerCase();
+
+  return journals
+    .filter(j => j.content.toLowerCase().includes(lowerQuery) || j.title.toLowerCase().includes(lowerQuery))
+    .slice(0, limit);
+}
+
+export async function generateJournalSummary(date?: string): Promise<string | null> {
+  const journal = await getOrCreateJournal(date);
+  const metadata = journal.metadata as JournalMetadata;
+
+  if (!metadata.entries?.length) {
+    return null;
+  }
+
+  const available = await isGenAvailable();
+  if (!available) {
+    // Fallback: simple summary
+    const count = metadata.entries.length;
+    return `${count} entries recorded.`;
+  }
+
+  const entriesText = metadata.entries
+    .map(e => `- ${e.time}: ${e.text}`)
+    .join('\n');
+
+  const prompt = `Summarize this day's journal entries in 2-3 sentences. Focus on accomplishments, decisions, and key points.
+
+Journal entries:
+${entriesText}
+
+Summary:`;
+
+  const summary = await generate(prompt);
+
+  if (summary) {
+    // Save summary to journal
+    await updateNode(journal.id, {
+      metadata: { ...metadata, summary },
+    });
+  }
+
+  return summary;
+}
+
+export function getJournalByDate(date: string): Node | null {
+  const title = `Journal: ${date}`;
+  return listNodes({ kind: 'memory', tags: ['journal'] })
+    .find(n => n.title === title) || null;
+}
+
+export function getTodayJournal(): Node | null {
+  return getJournalByDate(formatDate(new Date()));
+}
+
+export function getYesterdayJournal(): Node | null {
+  return getJournalByDate(getDateFromOffset('yesterday'));
+}
+
+export { formatDate, formatTime, getDateFromOffset };
diff --git a/src/mcp/index.ts b/src/mcp/index.ts
index 703c028..b1d2600 100644
--- a/src/mcp/index.ts
+++ b/src/mcp/index.ts
@@ -590,6 +590,66 @@ server.tool(
   }
 );
 
+// --- memory_journal ---
+import { getOrCreateJournal, appendToJournal, listJournals, generateJournalSummary, JournalMetadata } from '../core/journal';
+
+server.tool(
+  'memory_journal',
+  'Get or create today\'s journal, or add an entry to it',
+  {
+    text: z.string().optional().describe('Text to add to journal (if omitted, returns current journal)'),
+    date: z.string().optional().describe('Specific date (YYYY-MM-DD)'),
+    tags: z.array(z.string()).optional().describe('Tags for the entry'),
+  },
+  async ({ text, date, tags }) => {
+    if (text) {
+      const { journal, entry } = await appendToJournal(text, { tags, date });
+      const meta = journal.metadata as JournalMetadata;
+      return { content: [{ type: 'text' as const, text: serialize({ added: true, date: meta.date, entry }) }] };
+    }
+    const journal = await getOrCreateJournal(date);
+    return { content: [{ type: 'text' as const, text: serialize(journal) }] };
+  }
+);
+
+server.tool(
+  'memory_journal_list',
+  'List recent journals',
+  {
+    limit: z.number().optional().describe('Max journals to return (default: 10)'),
+    month: z.string().optional().describe('Filter by month (YYYY-MM)'),
+  },
+  async ({ limit, month }) => {
+    const journals = listJournals({ limit: limit || 10, month });
+    return {
+      content: [{
+        type: 'text' as const,
+        text: serialize(journals.map(j => {
+          const meta = j.metadata as JournalMetadata;
+          return {
+            id: j.id,
+            date: meta.date,
+            entries: meta.entries?.length || 0,
+            hasSummary: !!meta.summary,
+          };
+        })),
+      }],
+    };
+  }
+);
+
+server.tool(
+  'memory_journal_summarize',
+  'Generate AI summary for a journal',
+  {
+    date: z.string().optional().describe('Date to summarize (default: today)'),
+  },
+  async ({ date }) => {
+    const summary = await generateJournalSummary(date);
+    return { content: [{ type: 'text' as const, text: serialize({ summary }) }] };
+  }
+);
+
 // --- memory_index ---
 import { indexProject } from '../core/indexer';