Move database storage to platform-specific directories

README.md

@@ -58,7 +58,7 @@ Can you create a plan for this?"
 ```
 
 Claude will use the `create_plan` tool, which:
-- Creates a plan in SQLite (`~/.boost/boost.db`)
+- Creates a plan in SQLite (see Database location below)
 - Starts a web server on `localhost:3456`
 - Opens your browser to the plan UI
 - Returns the plan URL
@@ -135,7 +135,11 @@ Another instance is running. Kill it or change the port in `src/mcp-server.ts` (
 
 **Database location**
 
-Plans are stored in `~/.boost/boost.db`. Delete this file to reset.
+Plans are stored in:
+- **macOS**: `~/Library/boost/boost.db`
+- **Linux**: `$XDG_DATA_HOME/boost/boost.db` (or `~/.local/state/boost/boost.db` if `XDG_DATA_HOME` is not set)
+
+Delete this file to reset.
 
 **WebSocket connection failed**
 
@@ -155,7 +159,7 @@ npm run seed       # populate test data
 
 - **MCP server** (stdio) — exposes tools to Claude
 - **Express + WebSocket** (localhost:3456) — serves UI and pushes real-time updates
-- **SQLite** (`~/.boost/boost.db`) — stores plans, sections, comments, provocations
+- **SQLite** (platform-specific location) — stores plans, sections, comments, provocations
 - **Svelte 5 frontend** — reactive UI with markdown editing and diff view
 
 ## License

src/server/db.ts

@@ -1,7 +1,7 @@
 import Database from 'better-sqlite3';
 import { mkdirSync } from 'fs';
-import { join } from 'path';
-import { homedir } from 'os';
+import { join, dirname } from 'path';
+import { homedir, platform } from 'os';
 import { v4 as uuid } from 'uuid';
 import type {
   Plan,
@@ -14,9 +14,28 @@ import type {
   FeedbackResult,
 } from './types.js';
 
-const dbDir = join(homedir(), '.boost');
+function getDbPath(): string {
+  const home = homedir();
+  const plat = platform();
+
+  if (plat === 'darwin') {
+    // macOS: ~/Library/boost/boost.db
+    return join(home, 'Library', 'boost', 'boost.db');
+  } else {
+    // Linux and others: $XDG_DATA_HOME/boost/boost.db or $HOME/.local/state/boost/boost.db
+    // Note: Using .local/state instead of .local/share (XDG_DATA_HOME default) for state data
+    const xdgDataHome = process.env.XDG_DATA_HOME;
+    if (xdgDataHome) {
+      return join(xdgDataHome, 'boost', 'boost.db');
+    } else {
+      return join(home, '.local', 'state', 'boost', 'boost.db');
+    }
+  }
+}
+
+const dbPath = getDbPath();
+const dbDir = dirname(dbPath);
 mkdirSync(dbDir, { recursive: true });
-const dbPath = join(dbDir, 'boost.db');
 
 const db = new Database(dbPath);
 db.pragma('journal_mode = WAL');