Add context injection system (Milestone 3)

- Add src/core/context.ts with context gathering, ranking, and formatting
- Add src/core/config.ts for persistent configuration storage
- Add CLI commands: cortex context, cortex context-hook, cortex config
- Add memory_context MCP tool for Claude Code integration
- Add GET /api/context endpoint
- Include summary.ts from main branch for heartbeat dependency

src/cli/commands/config.ts

@@ -0,0 +1,81 @@
+import { Command } from 'commander';
+import chalk from 'chalk';
+import { getConfig, setConfig, listConfig, resetConfig, CortexConfig } from '../../core/config';
+
+export const configCommand = new Command('config')
+  .description('Manage Cortex configuration');
+
+configCommand
+  .command('get <key>')
+  .description('Get a config value')
+  .action((key: string) => {
+    try {
+      const value = getConfig(key as keyof CortexConfig);
+      console.log(value);
+    } catch (err) {
+      console.error(chalk.red(`Unknown config key: ${key}`));
+      process.exit(1);
+    }
+  });
+
+configCommand
+  .command('set <key> <value>')
+  .description('Set a config value')
+  .action((key: string, value: string) => {
+    // Validate key exists
+    const validKeys = [
+      'context.maxTokens',
+      'context.maxNodes',
+      'context.includeRecent',
+      'context.includeProject',
+      'context.includeTasks',
+      'context.includeDecisions',
+    ];
+
+    if (!validKeys.includes(key)) {
+      console.error(chalk.red(`Unknown config key: ${key}`));
+      console.error(chalk.dim(`Valid keys: ${validKeys.join(', ')}`));
+      process.exit(1);
+    }
+
+    // Parse value based on key type
+    let parsed: string | number | boolean = value;
+    if (key.startsWith('context.max')) {
+      parsed = parseInt(value, 10);
+      if (isNaN(parsed)) {
+        console.error(chalk.red(`Invalid number: ${value}`));
+        process.exit(1);
+      }
+    } else if (key.startsWith('context.include')) {
+      if (value !== 'true' && value !== 'false') {
+        console.error(chalk.red(`Invalid boolean: ${value} (use true or false)`));
+        process.exit(1);
+      }
+      parsed = value === 'true';
+    }
+
+    setConfig(key as keyof CortexConfig, parsed as any);
+    console.log(chalk.green(`Set ${key} = ${parsed}`));
+  });
+
+configCommand
+  .command('list')
+  .description('List all config values')
+  .action(() => {
+    const configs = listConfig();
+    console.log(chalk.bold('Configuration:'));
+    console.log();
+
+    for (const { key, value, isDefault } of configs) {
+      const displayValue = isDefault ? chalk.dim(`${value} (default)`) : chalk.cyan(value);
+      console.log(`  ${chalk.yellow(key)}: ${displayValue}`);
+    }
+  });
+
+configCommand
+  .command('reset <key>')
+  .description('Reset a config key to default')
+  .action((key: string) => {
+    resetConfig(key as keyof CortexConfig);
+    console.log(chalk.green(`Reset ${key} to default`));
+  });

src/cli/commands/context.ts

@@ -0,0 +1,85 @@
+import { Command } from 'commander';
+import chalk from 'chalk';
+import * as path from 'path';
+import { gatherContext, DEFAULT_CONTEXT_CONFIG } from '../../core/context';
+
+export const contextCommand = new Command('context')
+  .description('Preview or inject context for a Claude session')
+  .option('-p, --project <name>', 'Project name (defaults to current directory name)')
+  .option('-q, --query <text>', 'Additional semantic search query')
+  .option('--max-tokens <n>', 'Maximum tokens', String(DEFAULT_CONTEXT_CONFIG.maxTokens))
+  .option('--max-nodes <n>', 'Maximum nodes', String(DEFAULT_CONTEXT_CONFIG.maxNodes))
+  .option('--format <fmt>', 'Output format: markdown or json', 'markdown')
+  .option('--no-recent', 'Exclude recent activity')
+  .option('--no-tasks', 'Exclude open tasks')
+  .option('--no-decisions', 'Exclude decisions')
+  .action(async (opts) => {
+    const project = opts.project ?? path.basename(process.cwd());
+
+    const result = await gatherContext({
+      project,
+      semanticQuery: opts.query,
+      config: {
+        maxTokens: parseInt(opts.maxTokens),
+        maxNodes: parseInt(opts.maxNodes),
+        includeRecent: opts.recent !== false,
+        includeTasks: opts.tasks !== false,
+        includeDecisions: opts.decisions !== false,
+      },
+    });
+
+    if (opts.format === 'json') {
+      console.log(JSON.stringify({
+        project,
+        nodeCount: result.nodes.length,
+        nodes: result.nodes.map(r => ({
+          id: r.node.id,
+          kind: r.node.kind,
+          title: r.node.title,
+          score: r.score,
+          reason: r.reason,
+        })),
+      }, null, 2));
+      return;
+    }
+
+    // Markdown output
+    if (result.nodes.length === 0) {
+      console.log(chalk.yellow('No relevant context found.'));
+      return;
+    }
+
+    console.log(chalk.cyan(`# Context for ${project}`));
+    console.log(chalk.dim(`(${result.nodes.length} nodes)`));
+    console.log();
+    console.log(result.formatted);
+  });
+
+/**
+ * Hook command for Claude Code integration
+ * Outputs context to stdout for injection
+ */
+export const contextHookCommand = new Command('context-hook')
+  .description('Hook handler for Claude Code session start (outputs context to stdout)')
+  .option('-p, --project <name>', 'Project name (defaults to current directory name)')
+  .option('--max-tokens <n>', 'Maximum tokens', String(DEFAULT_CONTEXT_CONFIG.maxTokens))
+  .action(async (opts) => {
+    const project = opts.project ?? path.basename(process.cwd());
+
+    const result = await gatherContext({
+      project,
+      config: {
+        maxTokens: parseInt(opts.maxTokens),
+      },
+    });
+
+    if (result.nodes.length === 0) {
+      // Output nothing if no context
+      return;
+    }
+
+    // Output markdown directly to stdout for Claude to consume
+    console.log(`<cortex-context project="${project}">`);
+    console.log(result.formatted);
+    console.log('</cortex-context>');
+  });

src/cli/index.ts

@@ -11,6 +11,8 @@ import { graphCommand } from './commands/graph';
 import { serveCommand } from './commands/serve';
 import { decayCommand } from './commands/decay';
 import { childrenCommand } from './commands/children';
+import { contextCommand, contextHookCommand } from './commands/context';
+import { configCommand } from './commands/config';
 import { closeDb } from '../core/db';
 
 const program = new Command();
@@ -31,6 +33,9 @@ program.addCommand(graphCommand);
 program.addCommand(serveCommand);
 program.addCommand(decayCommand);
 program.addCommand(childrenCommand);
+program.addCommand(contextCommand);
+program.addCommand(contextHookCommand);
+program.addCommand(configCommand);
 
 program.hook('postAction', () => {
   closeDb();

src/core/config.ts

@@ -0,0 +1,119 @@
+import { getDb } from './db';
+
+export interface CortexConfig {
+  // Context injection settings
+  'context.maxTokens': number;
+  'context.maxNodes': number;
+  'context.includeRecent': boolean;
+  'context.includeProject': boolean;
+  'context.includeTasks': boolean;
+  'context.includeDecisions': boolean;
+}
+
+const DEFAULTS: CortexConfig = {
+  'context.maxTokens': 4000,
+  'context.maxNodes': 20,
+  'context.includeRecent': true,
+  'context.includeProject': true,
+  'context.includeTasks': true,
+  'context.includeDecisions': true,
+};
+
+/**
+ * Ensure the config table exists
+ */
+function ensureConfigTable(): void {
+  const db = getDb();
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS config (
+      key TEXT PRIMARY KEY,
+      value TEXT NOT NULL,
+      updated_at INTEGER NOT NULL
+    )
+  `);
+}
+
+/**
+ * Get a config value
+ */
+export function getConfig<K extends keyof CortexConfig>(key: K): CortexConfig[K] {
+  ensureConfigTable();
+  const db = getDb();
+  const row = db.prepare('SELECT value FROM config WHERE key = ?').get(key) as { value: string } | undefined;
+
+  if (!row) {
+    return DEFAULTS[key];
+  }
+
+  // Parse based on expected type
+  const defaultValue = DEFAULTS[key];
+  if (typeof defaultValue === 'boolean') {
+    return (row.value === 'true') as unknown as CortexConfig[K];
+  }
+  if (typeof defaultValue === 'number') {
+    return parseInt(row.value, 10) as unknown as CortexConfig[K];
+  }
+  return row.value as unknown as CortexConfig[K];
+}
+
+/**
+ * Set a config value
+ */
+export function setConfig<K extends keyof CortexConfig>(key: K, value: CortexConfig[K]): void {
+  ensureConfigTable();
+  const db = getDb();
+  const now = Date.now();
+  const strValue = String(value);
+
+  db.prepare(`
+    INSERT INTO config (key, value, updated_at)
+    VALUES (?, ?, ?)
+    ON CONFLICT(key) DO UPDATE SET value = ?, updated_at = ?
+  `).run(key, strValue, now, strValue, now);
+}
+
+/**
+ * List all config values
+ */
+export function listConfig(): Array<{ key: string; value: string; isDefault: boolean }> {
+  ensureConfigTable();
+  const db = getDb();
+  const rows = db.prepare('SELECT key, value FROM config').all() as Array<{ key: string; value: string }>;
+  const stored = new Map(rows.map(r => [r.key, r.value]));
+
+  const result: Array<{ key: string; value: string; isDefault: boolean }> = [];
+
+  for (const [key, defaultValue] of Object.entries(DEFAULTS)) {
+    const storedValue = stored.get(key);
+    if (storedValue !== undefined) {
+      result.push({ key, value: storedValue, isDefault: false });
+    } else {
+      result.push({ key, value: String(defaultValue), isDefault: true });
+    }
+  }
+
+  return result;
+}
+
+/**
+ * Reset a config key to default
+ */
+export function resetConfig(key: keyof CortexConfig): void {
+  ensureConfigTable();
+  const db = getDb();
+  db.prepare('DELETE FROM config WHERE key = ?').run(key);
+}
+
+/**
+ * Get context config as a structured object
+ */
+export function getContextConfig() {
+  return {
+    maxTokens: getConfig('context.maxTokens'),
+    maxNodes: getConfig('context.maxNodes'),
+    includeRecent: getConfig('context.includeRecent'),
+    includeProject: getConfig('context.includeProject'),
+    includeTasks: getConfig('context.includeTasks'),
+    includeDecisions: getConfig('context.includeDecisions'),
+  };
+}

src/core/context.ts

@@ -0,0 +1,291 @@
+import { getDb } from './db';
+import { query, listNodes } from './store';
+import { Node, NodeKind } from '../types';
+import { getContextConfig } from './config';
+
+export interface RankedNode {
+  node: Node;
+  score: number;
+  reason: 'recent' | 'project' | 'task' | 'decision' | 'semantic';
+}
+
+export interface ContextConfig {
+  maxTokens: number;
+  maxNodes: number;
+  includeRecent: boolean;
+  includeProject: boolean;
+  includeTasks: boolean;
+  includeDecisions: boolean;
+}
+
+export const DEFAULT_CONTEXT_CONFIG: ContextConfig = {
+  maxTokens: 4000,
+  maxNodes: 20,
+  includeRecent: true,
+  includeProject: true,
+  includeTasks: true,
+  includeDecisions: true,
+};
+
+/**
+ * Get nodes accessed within the last N hours
+ */
+export function getRecentNodes(hours: number = 48, limit: number = 10): Node[] {
+  const db = getDb();
+  const cutoff = Date.now() - hours * 60 * 60 * 1000;
+
+  const rows = db.prepare(`
+    SELECT * FROM nodes
+    WHERE is_stale = 0 AND last_accessed_at > ?
+    ORDER BY last_accessed_at DESC
+    LIMIT ?
+  `).all(cutoff, limit) as any[];
+
+  return rows.map(rowToNode);
+}
+
+/**
+ * Get nodes tagged with a specific project name
+ */
+export function getProjectNodes(projectName: string, limit: number = 10): Node[] {
+  return listNodes({ tags: [projectName.toLowerCase()], limit });
+}
+
+/**
+ * Get open tasks (status: todo, in_progress, or active)
+ */
+export function getOpenTasks(limit: number = 10): Node[] {
+  const db = getDb();
+
+  const rows = db.prepare(`
+    SELECT * FROM nodes
+    WHERE is_stale = 0
+      AND kind = 'task'
+      AND (status = 'todo' OR status = 'in_progress' OR status = 'active' OR status IS NULL)
+    ORDER BY updated_at DESC
+    LIMIT ?
+  `).all(limit) as any[];
+
+  return rows.map(rowToNode);
+}
+
+/**
+ * Get recent decisions
+ */
+export function getRecentDecisions(limit: number = 5): Node[] {
+  return listNodes({ kind: 'decision', limit });
+}
+
+/**
+ * Get semantic matches for a query
+ */
+export async function getSemanticMatches(queryText: string, limit: number = 10): Promise<RankedNode[]> {
+  const results = await query(queryText, { limit });
+  return results.map(r => ({
+    node: r.node,
+    score: r.score,
+    reason: 'semantic' as const,
+  }));
+}
+
+/**
+ * Estimate token count for a node (rough approximation)
+ */
+function estimateTokens(node: Node): number {
+  const text = `${node.title} ${node.content || ''} ${node.tags.join(' ')}`;
+  // Rough estimate: 1 token ≈ 4 characters
+  return Math.ceil(text.length / 4);
+}
+
+/**
+ * Deduplicate and rank nodes, keeping highest score per node
+ */
+function dedupeAndRank(candidates: RankedNode[]): RankedNode[] {
+  const byId = new Map<string, RankedNode>();
+
+  for (const c of candidates) {
+    const existing = byId.get(c.node.id);
+    if (!existing || c.score > existing.score) {
+      byId.set(c.node.id, c);
+    }
+  }
+
+  return Array.from(byId.values()).sort((a, b) => b.score - a.score);
+}
+
+/**
+ * Select nodes within token budget
+ */
+function selectWithinBudget(candidates: RankedNode[], maxTokens: number, maxNodes: number): RankedNode[] {
+  const selected: RankedNode[] = [];
+  let totalTokens = 0;
+
+  for (const c of candidates) {
+    if (selected.length >= maxNodes) break;
+
+    const tokens = estimateTokens(c.node);
+    if (totalTokens + tokens > maxTokens) continue;
+
+    selected.push(c);
+    totalTokens += tokens;
+  }
+
+  return selected;
+}
+
+/**
+ * Group nodes by their reason
+ */
+function groupByReason(nodes: RankedNode[]): Record<string, RankedNode[]> {
+  const groups: Record<string, RankedNode[]> = {};
+
+  for (const n of nodes) {
+    if (!groups[n.reason]) groups[n.reason] = [];
+    groups[n.reason].push(n);
+  }
+
+  return groups;
+}
+
+/**
+ * Format a single node for context output
+ */
+function formatNode(ranked: RankedNode): string {
+  const n = ranked.node;
+  const lines: string[] = [];
+
+  lines.push(`### ${n.title}`);
+  if (n.content) {
+    // Truncate long content
+    const content = n.content.length > 500 ? n.content.slice(0, 500) + '...' : n.content;
+    lines.push(content);
+  }
+  if (n.tags.length) {
+    lines.push(`*Tags: ${n.tags.join(', ')}*`);
+  }
+
+  return lines.join('\n');
+}
+
+/**
+ * Format context as markdown
+ */
+export function formatContext(nodes: RankedNode[]): string {
+  if (nodes.length === 0) {
+    return '*No relevant context found.*';
+  }
+
+  const groups = groupByReason(nodes);
+  const sections: string[] = [];
+
+  // Order: project > decisions > tasks > recent > semantic
+  const order: Array<{ key: string; title: string }> = [
+    { key: 'project', title: 'Project Context' },
+    { key: 'decision', title: 'Key Decisions' },
+    { key: 'task', title: 'Open Tasks' },
+    { key: 'recent', title: 'Recent Activity' },
+    { key: 'semantic', title: 'Related Memories' },
+  ];
+
+  for (const { key, title } of order) {
+    const group = groups[key];
+    if (group?.length) {
+      sections.push(`## ${title}\n\n${group.map(formatNode).join('\n\n')}`);
+    }
+  }
+
+  return sections.join('\n\n---\n\n');
+}
+
+/**
+ * Main context gathering function
+ */
+export async function gatherContext(
+  options: {
+    project?: string;
+    semanticQuery?: string;
+    config?: Partial<ContextConfig>;
+  } = {}
+): Promise<{ nodes: RankedNode[]; formatted: string }> {
+  // Load stored config, then override with any passed options
+  const storedConfig = getContextConfig();
+  const config = { ...storedConfig, ...options.config };
+  const candidates: RankedNode[] = [];
+
+  // 1. Project-specific nodes (highest priority)
+  if (config.includeProject && options.project) {
+    const projectNodes = getProjectNodes(options.project, 10);
+    candidates.push(...projectNodes.map(node => ({
+      node,
+      score: 0.95,
+      reason: 'project' as const,
+    })));
+  }
+
+  // 2. Recent decisions
+  if (config.includeDecisions) {
+    const decisions = getRecentDecisions(5);
+    candidates.push(...decisions.map(node => ({
+      node,
+      score: 0.85,
+      reason: 'decision' as const,
+    })));
+  }
+
+  // 3. Open tasks
+  if (config.includeTasks) {
+    const tasks = getOpenTasks(5);
+    candidates.push(...tasks.map(node => ({
+      node,
+      score: 0.80,
+      reason: 'task' as const,
+    })));
+  }
+
+  // 4. Recent activity
+  if (config.includeRecent) {
+    const recent = getRecentNodes(48, 10);
+    candidates.push(...recent.map(node => ({
+      node,
+      score: 0.70,
+      reason: 'recent' as const,
+    })));
+  }
+
+  // 5. Semantic search on project context
+  if (options.semanticQuery) {
+    const semantic = await getSemanticMatches(options.semanticQuery, 10);
+    // Scale semantic scores to fit our priority scheme
+    candidates.push(...semantic.map(r => ({
+      ...r,
+      score: r.score * 0.6, // Max 0.6 for semantic matches
+    })));
+  }
+
+  // Dedupe, rank, and select within budget
+  const ranked = dedupeAndRank(candidates);
+  const selected = selectWithinBudget(ranked, config.maxTokens, config.maxNodes);
+
+  return {
+    nodes: selected,
+    formatted: formatContext(selected),
+  };
+}
+
+// Helper to convert DB row to Node (duplicated from store.ts to avoid circular deps)
+function rowToNode(row: any): Node {
+  return {
+    id: row.id,
+    kind: row.kind,
+    title: row.title,
+    content: row.content,
+    status: row.status ?? undefined,
+    tags: JSON.parse(row.tags || '[]'),
+    metadata: JSON.parse(row.metadata || '{}'),
+    embedding: null, // Don't load embeddings for context
+    createdAt: row.created_at,
+    updatedAt: row.updated_at,
+    lastAccessedAt: row.last_accessed_at ?? row.updated_at,
+    isStale: !!row.is_stale,
+  };
+}

src/core/summary.ts

@@ -0,0 +1,165 @@
+import { getDb } from './db';
+import { isGenAvailable, generate } from './search/ollamaGen';
+
+export interface SummaryData {
+  generatedAt: number;
+  overview: string;
+  components: { title: string; status?: string; summary?: string }[];
+  decisions: { title: string; status?: string }[];
+  tasks: { todo: string[]; in_progress: string[]; done: string[] };
+  memories: { byTag: Record<string, string[]> };
+  stats: { total: number; stale: number; orphans: number; edges: number };
+}
+
+// Ensure cache table exists
+function ensureCacheTable(): void {
+  const db = getDb();
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS system_cache (
+      key TEXT PRIMARY KEY,
+      value TEXT NOT NULL,
+      updated_at INTEGER NOT NULL
+    )
+  `);
+}
+
+export function getCachedSummary(): SummaryData | null {
+  ensureCacheTable();
+  const db = getDb();
+  const row = db.prepare('SELECT value FROM system_cache WHERE key = ?').get('summary') as { value: string } | undefined;
+  if (!row) return null;
+  try {
+    return JSON.parse(row.value);
+  } catch {
+    return null;
+  }
+}
+
+export function cacheSummary(data: SummaryData): void {
+  ensureCacheTable();
+  const db = getDb();
+  db.prepare(`
+    INSERT INTO system_cache (key, value, updated_at) VALUES (?, ?, ?)
+    ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = excluded.updated_at
+  `).run('summary', JSON.stringify(data), Date.now());
+}
+
+export async function generateSummary(): Promise<SummaryData> {
+  const db = getDb();
+  const now = Date.now();
+
+  // Gather all active nodes
+  const rows = db.prepare(`
+    SELECT id, kind, title, status, tags, metadata, content
+    FROM nodes WHERE is_stale = 0
+    ORDER BY kind, title
+  `).all() as any[];
+
+  // Stats
+  const totalNodes = rows.length;
+  const staleCount = (db.prepare('SELECT COUNT(*) as c FROM nodes WHERE is_stale = 1').get() as any).c;
+  const edgeCount = (db.prepare('SELECT COUNT(*) as c FROM edges').get() as any).c;
+
+  const edgeRows = db.prepare('SELECT from_id, to_id FROM edges').all() as any[];
+  const hasEdge = new Set<string>();
+  for (const e of edgeRows) {
+    hasEdge.add(e.from_id);
+    hasEdge.add(e.to_id);
+  }
+  const orphanCount = rows.filter(r => !hasEdge.has(r.id)).length;
+
+  // Categorize nodes
+  const components: SummaryData['components'] = [];
+  const decisions: SummaryData['decisions'] = [];
+  const tasks: SummaryData['tasks'] = { todo: [], in_progress: [], done: [] };
+  const memoryTags: Record<string, string[]> = {};
+
+  for (const row of rows) {
+    const meta = JSON.parse(row.metadata || '{}');
+
+    if (row.kind === 'component') {
+      components.push({
+        title: row.title,
+        status: row.status,
+        summary: meta.summary || (row.content?.slice(0, 100) + (row.content?.length > 100 ? '...' : '')),
+      });
+    } else if (row.kind === 'decision') {
+      decisions.push({ title: row.title, status: row.status });
+    } else if (row.kind === 'task') {
+      const status = (row.status || 'todo').toLowerCase();
+      if (status === 'done' || status === 'completed') {
+        tasks.done.push(row.title);
+      } else if (status === 'in_progress' || status === 'in-progress') {
+        tasks.in_progress.push(row.title);
+      } else {
+        tasks.todo.push(row.title);
+      }
+    } else if (row.kind === 'memory') {
+      const tags: string[] = JSON.parse(row.tags || '[]');
+      // Group by first tag, or 'untagged'
+      const primaryTag = tags[0] || 'untagged';
+      if (!memoryTags[primaryTag]) memoryTags[primaryTag] = [];
+      memoryTags[primaryTag].push(row.title);
+    }
+  }
+
+  // Sort tags by count descending, limit to top 10
+  const sortedTags = Object.entries(memoryTags)
+    .sort((a, b) => b[1].length - a[1].length)
+    .slice(0, 10);
+  const limitedMemoryTags: Record<string, string[]> = {};
+  for (const [tag, titles] of sortedTags) {
+    // Limit to 5 titles per tag
+    limitedMemoryTags[tag] = titles.slice(0, 5);
+    if (titles.length > 5) {
+      limitedMemoryTags[tag].push(`+${titles.length - 5} more`);
+    }
+  }
+
+  // Generate overview
+  let overview: string;
+  const aiAvailable = await isGenAvailable();
+
+  if (aiAvailable) {
+    const prompt = `Write a single sentence (max 30 words) summarizing this knowledge graph for a developer starting a coding session.
+
+Stats: ${totalNodes} nodes (${components.length} components, ${decisions.length} decisions, ${tasks.todo.length + tasks.in_progress.length + tasks.done.length} tasks, ${totalNodes - components.length - decisions.length - tasks.todo.length - tasks.in_progress.length - tasks.done.length} memories), ${edgeCount} edges.
+
+Components: ${components.map(c => c.title).join(', ')}
+Active tasks: ${[...tasks.todo, ...tasks.in_progress].join(', ') || 'none'}
+
+Output ONLY the summary sentence.`;
+
+    const aiOverview = await generate(prompt);
+    overview = aiOverview || buildFallbackOverview(totalNodes, components.length, decisions.length, tasks, edgeCount);
+  } else {
+    overview = buildFallbackOverview(totalNodes, components.length, decisions.length, tasks, edgeCount);
+  }
+
+  const summary: SummaryData = {
+    generatedAt: now,
+    overview,
+    components,
+    decisions,
+    tasks,
+    memories: { byTag: limitedMemoryTags },
+    stats: { total: totalNodes, stale: staleCount, orphans: orphanCount, edges: edgeCount },
+  };
+
+  cacheSummary(summary);
+  return summary;
+}
+
+function buildFallbackOverview(
+  total: number,
+  components: number,
+  decisions: number,
+  tasks: SummaryData['tasks'],
+  edges: number
+): string {
+  const pending = tasks.todo.length + tasks.in_progress.length;
+  const parts = [`${total} nodes`, `${components} components`, `${decisions} decisions`];
+  if (pending > 0) parts.push(`${pending} open tasks`);
+  parts.push(`${edges} edges`);
+  return parts.join(', ') + '.';
+}

src/mcp/index.ts

@@ -367,6 +367,37 @@ server.tool(
   }
 );
 
+// --- memory_context ---
+import { gatherContext, DEFAULT_CONTEXT_CONFIG } from '../core/context';
+
+server.tool(
+  'memory_context',
+  'Get relevant context for a Claude session. Gathers recent activity, project-specific nodes, open tasks, and decisions. Use at session start.',
+  {
+    project: z.string().optional().describe('Project name to filter by (e.g. "cortex")'),
+    query: z.string().optional().describe('Optional semantic search query'),
+    maxTokens: z.number().optional().describe(`Max tokens in output (default ${DEFAULT_CONTEXT_CONFIG.maxTokens})`),
+    maxNodes: z.number().optional().describe(`Max nodes to include (default ${DEFAULT_CONTEXT_CONFIG.maxNodes})`),
+  },
+  async ({ project, query: semanticQuery, maxTokens, maxNodes }) => {
+    const result = await gatherContext({
+      project,
+      semanticQuery,
+      config: {
+        maxTokens: maxTokens ?? DEFAULT_CONTEXT_CONFIG.maxTokens,
+        maxNodes: maxNodes ?? DEFAULT_CONTEXT_CONFIG.maxNodes,
+      },
+    });
+
+    return {
+      content: [{
+        type: 'text' as const,
+        text: result.formatted,
+      }],
+    };
+  }
+);
+
 // --- memory_summary ---
 import { getCachedSummary, generateSummary } from '../core/summary';
 

src/server/routes.ts

@@ -4,6 +4,7 @@ import { getConnections, buildTree } from '../core/graph';
 import { getDb } from '../core/db';
 import { determineGroupingStrategy, groupResults } from './queryOrganizer';
 import { getLastReport, markDirty, runMaintenance } from './heartbeat';
+import { gatherContext } from '../core/context';
 
 const router = Router();
 
@@ -166,6 +167,42 @@ router.post('/maintenance/run', async (_req: Request, res: Response) => {
   }
 });
 
+// Context — get session context for Claude
+router.get('/context', async (req: Request, res: Response) => {
+  try {
+    const project = req.query.project as string | undefined;
+    const semanticQuery = req.query.query as string | undefined;
+    const maxTokens = req.query.maxTokens ? parseInt(req.query.maxTokens as string) : undefined;
+    const maxNodes = req.query.maxNodes ? parseInt(req.query.maxNodes as string) : undefined;
+    const format = req.query.format as string || 'markdown';
+
+    const result = await gatherContext({
+      project,
+      semanticQuery,
+      config: { maxTokens, maxNodes } as any,
+    });
+
+    if (format === 'json') {
+      res.json({
+        project,
+        nodeCount: result.nodes.length,
+        nodes: result.nodes.map(r => ({
+          id: r.node.id,
+          kind: r.node.kind,
+          title: r.node.title,
+          score: r.score,
+          reason: r.reason,
+        })),
+        formatted: result.formatted,
+      });
+    } else {
+      res.type('text/markdown').send(result.formatted);
+    }
+  } catch (err: any) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
 // Prompt — AI-driven natural language instruction
 router.post('/prompt', async (req: Request, res: Response) => {
   try {