diff --git a/apps/server/src/services/memory/__tests__/entries.test.ts b/apps/server/src/services/memory/__tests__/entries.test.ts
new file mode 100644
index 0000000..a72588b
--- /dev/null
+++ b/apps/server/src/services/memory/__tests__/entries.test.ts
@@ -0,0 +1,31 @@
+import { describe, it, expect } from 'vitest';
+import { parseMemoryEntries } from '../entries.js';
+
+describe('parseMemoryEntries', () => {
+  it('parses a single entry with tags', () => {
+    const md = '## project: Indentation\n> tags: style\n\nUse two-space indentation\n';
+    const entries = parseMemoryEntries('style.md', md);
+    expect(entries).toHaveLength(1);
+    expect(entries[0].title).toBe('Indentation');
+    expect(entries[0].topic).toBe('project');
+    expect(entries[0].tags).toEqual(['style']);
+    expect(entries[0].content).toContain('two-space');
+  });
+
+  it('parses multiple entries', () => {
+    const md = [
+      '## project: Style',
+      '',
+      'Use tab indentation',
+      '',
+      '## user: Preference',
+      '',
+      'Prefer pnpm',
+      '',
+    ].join('\n');
+    const entries = parseMemoryEntries('mem.md', md);
+    expect(entries).toHaveLength(2);
+    expect(entries[0].topic).toBe('project');
+    expect(entries[1].topic).toBe('user');
+  });
+});
diff --git a/apps/server/src/services/memory/__tests__/paths.test.ts b/apps/server/src/services/memory/__tests__/paths.test.ts
new file mode 100644
index 0000000..45fc5c7
--- /dev/null
+++ b/apps/server/src/services/memory/__tests__/paths.test.ts
@@ -0,0 +1,14 @@
+import { describe, it, expect } from 'vitest';
+import { getMemoryRoot, getTopicDir } from '../paths.js';
+
+describe('getMemoryRoot', () => {
+  it('returns .boocode/memory under project root', () => {
+    expect(getMemoryRoot('/proj')).toBe('/proj/.boocode/memory');
+  });
+});
+
+describe('getTopicDir', () => {
+  it('returns project/ under memory root', () => {
+    expect(getTopicDir('/r/.boocode/memory', 'project')).toBe('/r/.boocode/memory/project');
+  });
+});
diff --git a/apps/server/src/services/memory/__tests__/prompt.test.ts b/apps/server/src/services/memory/__tests__/prompt.test.ts
new file mode 100644
index 0000000..59a72a7
--- /dev/null
+++ b/apps/server/src/services/memory/__tests__/prompt.test.ts
@@ -0,0 +1,15 @@
+import { describe, it, expect } from 'vitest';
+import { formatMemoryBlock } from '../prompt.js';
+
+describe('formatMemoryBlock', () => {
+  it('wraps entries in boocode-memory tags', () => {
+    const block = formatMemoryBlock(['Use pnpm', 'Tests in vitest']);
+    expect(block).toContain('<boocode-memory>');
+    expect(block).toContain('Use pnpm');
+    expect(block).toContain('</boocode-memory>');
+  });
+
+  it('returns empty string for no entries', () => {
+    expect(formatMemoryBlock([])).toBe('');
+  });
+});
diff --git a/apps/server/src/services/memory/__tests__/recall.test.ts b/apps/server/src/services/memory/__tests__/recall.test.ts
new file mode 100644
index 0000000..bc345e0
--- /dev/null
+++ b/apps/server/src/services/memory/__tests__/recall.test.ts
@@ -0,0 +1,15 @@
+import { describe, it, expect } from 'vitest';
+import { rankByRelevance } from '../recall.js';
+import type { MemoryEntry } from '../entries.js';
+
+describe('rankByRelevance', () => {
+  it('returns entries matching query keywords', () => {
+    const entries: MemoryEntry[] = [
+      { id: '1', topic: 'project', title: 'Style', content: 'Use two-space indentation', tags: ['style'] },
+      { id: '2', topic: 'project', title: 'Tests', content: 'Use vitest for testing', tags: ['testing'] },
+    ];
+    const result = rankByRelevance('what indentation?', entries);
+    expect(result).toHaveLength(1);
+    expect(result[0].title).toBe('Style');
+  });
+});
diff --git a/apps/server/src/services/memory/entries.ts b/apps/server/src/services/memory/entries.ts
new file mode 100644
index 0000000..0e8bd66
--- /dev/null
+++ b/apps/server/src/services/memory/entries.ts
@@ -0,0 +1,54 @@
+export interface MemoryEntry {
+  id: string;
+  topic: string;
+  title: string;
+  content: string;
+  tags: string[];
+}
+
+export function parseMemoryEntries(fileName: string, markdown: string): MemoryEntry[] {
+  const entries: MemoryEntry[] = [];
+  const lines = markdown.split('\n');
+  let currentEntry: Partial<MemoryEntry> | null = null;
+  let currentContent: string[] = [];
+
+  for (const line of lines) {
+    const headingMatch = line.match(/^##\s+(.+):\s+(.+)$/);
+    if (headingMatch && headingMatch[1] && headingMatch[2]) {
+      if (currentEntry && currentEntry.title) {
+        entries.push({
+          id: `${fileName}-${entries.length}`,
+          topic: currentEntry.topic ?? '',
+          title: currentEntry.title,
+          content: currentContent.join('\n').trim(),
+          tags: currentEntry.tags ?? [],
+        });
+      }
+      currentEntry = { topic: headingMatch[1].trim(), title: headingMatch[2].trim(), tags: [] };
+      currentContent = [];
+      continue;
+    }
+
+    const tagsMatch = line.match(/^>\s*tags:\s*(.+)$/i);
+    if (tagsMatch && tagsMatch[1] && currentEntry) {
+      currentEntry.tags = tagsMatch[1].split(',').map((t) => t.trim());
+      continue;
+    }
+
+    if (currentEntry) {
+      currentContent.push(line);
+    }
+  }
+
+  if (currentEntry && currentEntry.title) {
+    entries.push({
+      id: `${fileName}-${entries.length}`,
+      topic: currentEntry.topic ?? '',
+      title: currentEntry.title,
+      content: currentContent.join('\n').trim(),
+      tags: currentEntry.tags ?? [],
+    });
+  }
+
+  return entries;
+}
diff --git a/apps/server/src/services/memory/index.ts b/apps/server/src/services/memory/index.ts
new file mode 100644
index 0000000..9b1fae1
--- /dev/null
+++ b/apps/server/src/services/memory/index.ts
@@ -0,0 +1,6 @@
+export { loadMemoryForSession } from './recall.js';
+export { formatMemoryBlock } from './prompt.js';
+export { scanMemoryScopes } from './scan.js';
+export { parseMemoryEntries } from './entries.js';
+export { ensureMemoryScaffold, getMemoryRoot } from './paths.js';
+export type { MemoryEntry } from './entries.js';
diff --git a/apps/server/src/services/memory/paths.ts b/apps/server/src/services/memory/paths.ts
new file mode 100644
index 0000000..026ab47
--- /dev/null
+++ b/apps/server/src/services/memory/paths.ts
@@ -0,0 +1,17 @@
+import { join } from 'node:path';
+import { mkdir } from 'node:fs/promises';
+
+const TOPICS = ['project', 'user', 'reference'] as const;
+export type MemoryTopic = (typeof TOPICS)[number];
+
+export function getMemoryRoot(projectRoot: string): string {
+  return join(projectRoot, '.boocode', 'memory');
+}
+
+export function getTopicDir(root: string, topic: MemoryTopic): string {
+  return join(root, topic);
+}
+
+export async function ensureMemoryScaffold(root: string): Promise<void> {
+  await Promise.all(TOPICS.map((t) => mkdir(join(root, t), { recursive: true })));
+}
diff --git a/apps/server/src/services/memory/prompt.ts b/apps/server/src/services/memory/prompt.ts
new file mode 100644
index 0000000..d565936
--- /dev/null
+++ b/apps/server/src/services/memory/prompt.ts
@@ -0,0 +1,5 @@
+export function formatMemoryBlock(entries: string[]): string {
+  if (entries.length === 0) return '';
+  const body = entries.map((e) => `- ${e}`).join('\n');
+  return `<boocode-memory>\n${body}\n</boocode-memory>`;
+}
diff --git a/apps/server/src/services/memory/recall.ts b/apps/server/src/services/memory/recall.ts
new file mode 100644
index 0000000..bd50114
--- /dev/null
+++ b/apps/server/src/services/memory/recall.ts
@@ -0,0 +1,44 @@
+import type { MemoryEntry } from './entries.js';
+import { scanProjectMemory } from './scan.js';
+
+function extractKeywords(query: string): string[] {
+  return query
+    .toLowerCase()
+    .replace(/[^a-z0-9\s]/g, '')
+    .split(/\s+/)
+    .filter((w) => w.length > 2);
+}
+
+export function rankByRelevance(query: string, entries: MemoryEntry[]): MemoryEntry[] {
+  const keywords = extractKeywords(query);
+  if (keywords.length === 0) return entries.slice(0, 5);
+
+  const scored = entries.map((entry) => {
+    let score = 0;
+    const searchText = `${entry.title} ${entry.content} ${entry.tags.join(' ')}`.toLowerCase();
+    for (const kw of keywords) {
+      if (entry.title.toLowerCase().includes(kw)) score += 3;
+      if (entry.tags.some((t) => t.toLowerCase().includes(kw))) score += 2;
+      if (entry.content.toLowerCase().includes(kw)) score += 1;
+    }
+    return { entry, score };
+  });
+
+  return scored
+    .filter((s) => s.score > 0)
+    .sort((a, b) => b.score - a.score)
+    .slice(0, 10)
+    .map((s) => s.entry);
+}
+
+export async function loadMemoryForSession(
+  projectRoot: string,
+  _sessionId?: string,
+  query?: string,
+): Promise<string[]> {
+  const entries = await scanProjectMemory(projectRoot);
+  if (entries.length === 0) return [];
+
+  const relevant = query ? rankByRelevance(query, entries) : entries.slice(0, 5);
+  return relevant.map((e) => `[${e.topic}] ${e.title}: ${e.content}`);
+}
diff --git a/apps/server/src/services/memory/scan.ts b/apps/server/src/services/memory/scan.ts
new file mode 100644
index 0000000..15ede25
--- /dev/null
+++ b/apps/server/src/services/memory/scan.ts
@@ -0,0 +1,72 @@
+import { homedir } from 'node:os';
+import { join } from 'node:path';
+import { readFile, readdir } from 'node:fs/promises';
+import type { MemoryEntry } from './entries.js';
+import { parseMemoryEntries } from './entries.js';
+import { getMemoryRoot } from './paths.js';
+
+export interface MemoryScope {
+  projectRoot: string;
+  sessionDir?: string;
+  homeDir?: string;
+}
+
+async function scanDirectory(dir: string): Promise<MemoryEntry[]> {
+  const entries: MemoryEntry[] = [];
+  try {
+    const files = await readdir(dir, { withFileTypes: true });
+    for (const file of files) {
+      if (file.isFile() && file.name.endsWith('.md')) {
+        const content = await readFile(join(dir, file.name), 'utf8');
+        entries.push(...parseMemoryEntries(file.name, content));
+      }
+    }
+  } catch {
+    // Directory doesn't exist
+  }
+  return entries;
+}
+
+const MEMORY_TOPICS = ['project', 'user', 'reference'] as const;
+
+async function scanTopicDirs(root: string): Promise<MemoryEntry[]> {
+  const entries: MemoryEntry[] = [];
+  for (const topic of MEMORY_TOPICS) {
+    entries.push(...(await scanDirectory(join(root, topic))));
+  }
+  return entries;
+}
+
+export async function scanMemoryScopes(scope: MemoryScope): Promise<MemoryEntry[]> {
+  const allEntries: MemoryEntry[] = [];
+
+  // 1. Global (~/.boocode/memory/) - lowest priority
+  allEntries.push(...(await scanTopicDirs(getMemoryRoot(homedir()))));
+
+  // 2. Home ($HOME/.boocode/memory)
+  const homeDir = scope.homeDir ?? homedir();
+  const homeRoot = getMemoryRoot(homeDir);
+  if (homeRoot !== getMemoryRoot(homedir())) {
+    allEntries.push(...(await scanTopicDirs(homeRoot)));
+  }
+
+  // 3. Project (.boocode/memory/ under project root)
+  allEntries.push(...(await scanTopicDirs(getMemoryRoot(scope.projectRoot))));
+
+  // 4. Session (.boocode/sessions/<id>/memory.md) - highest priority
+  if (scope.sessionDir) {
+    try {
+      const sessionFile = join(scope.sessionDir, 'memory.md');
+      const content = await readFile(sessionFile, 'utf8');
+      allEntries.push(...parseMemoryEntries('session-memory', content));
+    } catch {
+      // No session memory file
+    }
+  }
+
+  return allEntries;
+}
+
+export async function scanProjectMemory(projectRoot: string): Promise<MemoryEntry[]> {
+  return scanMemoryScopes({ projectRoot });
+}
diff --git a/apps/server/src/services/memory/store.ts b/apps/server/src/services/memory/store.ts
new file mode 100644
index 0000000..9347dde
--- /dev/null
+++ b/apps/server/src/services/memory/store.ts
@@ -0,0 +1,35 @@
+import { readFile, writeFile, readdir } from 'node:fs/promises';
+import { join } from 'node:path';
+import type { MemoryTopic } from './paths.js';
+import { getTopicDir } from './paths.js';
+
+export async function readTopicFiles(root: string, topic: MemoryTopic): Promise<Map<string, string>> {
+  const dir = getTopicDir(root, topic);
+  const files = new Map<string, string>();
+  try {
+    const entries = await readdir(dir, { withFileTypes: true });
+    for (const entry of entries) {
+      if (entry.isFile() && entry.name.endsWith('.md')) {
+        const content = await readFile(join(dir, entry.name), 'utf8');
+        files.set(entry.name, content);
+      }
+    }
+  } catch {
+    // Directory doesn't exist yet
+  }
+  return files;
+}
+
+export async function writeEntry(
+  root: string,
+  topic: MemoryTopic,
+  title: string,
+  content: string,
+  tags: string[],
+): Promise<void> {
+  const dir = getTopicDir(root, topic);
+  const tagLine = tags.length > 0 ? `> tags: ${tags.join(', ')}\n\n` : '\n';
+  const entry = `## ${topic}: ${title}\n${tagLine}${content}\n`;
+  const filename = title.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/(^-|-$)/g, '') + '.md';
+  await writeFile(join(dir, filename), entry, 'utf8');
+}
diff --git a/apps/server/src/services/system-prompt.ts b/apps/server/src/services/system-prompt.ts
index b9a21d5..a1dde52 100644
--- a/apps/server/src/services/system-prompt.ts
+++ b/apps/server/src/services/system-prompt.ts
@@ -22,6 +22,8 @@ import { readFile, stat } from 'node:fs/promises';
 import type { Agent, Project, Session } from '../types/api.js';
 import { getAgentsMtimes } from './agents.js';
 import { resolveRoute } from './inference/provider.js';
+import { loadMemoryForSession } from './memory/recall.js';
+import { formatMemoryBlock } from './memory/prompt.js';
 
 const BASE_SYSTEM_PROMPT = (projectPath: string) =>
   `You are BooCode Chat, a code investigation assistant. The user is working on a project located at ${projectPath}. Use the file-read tools (view_file, list_dir, grep, find_files) to investigate code when needed. Be concise. Cite file paths and line numbers when discussing code. Do not hallucinate file contents — read the file first. Tool results may be truncated; if so, narrow your query rather than guessing.`;
@@ -164,7 +166,11 @@ export async function buildSystemPromptWithFingerprint(
   let out = BASE_SYSTEM_PROMPT(project.path);
   const guidance = await getContainerGuidance();
   if (guidance) {
-    out += `\n\n--- Container guidance ---\n${guidance}\n--- end container guidance ---\n`;
+    out += '\n\n--- Container guidance ---\n' + guidance + '\n--- end container guidance ---\n';
+  }
+  const memory = await loadMemoryForSession(project.path, session.id).catch(() => []);
+  if (memory.length > 0) {
+    out += '\n\n' + formatMemoryBlock(memory);
   }
   if (agent && agent.system_prompt.trim().length > 0) {
     out += '\n\n' + agent.system_prompt.trim();