diff --git a/.env.example b/.env.example
index 4ca924b..acad8bf 100644
--- a/.env.example
+++ b/.env.example
@@ -6,9 +6,10 @@
 # Get one at: https://platform.openai.com/api-keys
 OPENAI_API_KEY=
 
-# Database path (defaults work for most users)
-# SQLITE_DB_PATH=~/Library/Application Support/RA-H/db/rah.sqlite
-SQLITE_VEC_EXTENSION_PATH=./vendor/sqlite-extensions/vec0.dylib
+# Database/vector paths are auto-detected for macOS, Windows, and Linux.
+# Override only if you intentionally want a custom location.
+# SQLITE_DB_PATH=/absolute/path/to/rah.sqlite
+# SQLITE_VEC_EXTENSION_PATH=/absolute/path/to/vec0.<dylib|dll|so>
 
 # App config (no changes needed)
 NODE_ENV=development
diff --git a/apps/mcp-server-standalone/README.md b/apps/mcp-server-standalone/README.md
index 91f5330..63e85a4 100644
--- a/apps/mcp-server-standalone/README.md
+++ b/apps/mcp-server-standalone/README.md
@@ -50,13 +50,13 @@ Restart Claude fully. If you need to freeze behavior for debugging, pin an exact
 ## Requirements
 
 - Node.js 18-22 LTS recommended
-- a RA-H database at `~/Library/Application Support/RA-H/db/rah.sqlite`, created by `setup`, `init-db`, or the app
+- a RA-H database at the platform default path, created by `setup`, `init-db`, or the app
 
 ## Environment Variables
 
 | Variable | Default | Description |
 |----------|---------|-------------|
-| `RAH_DB_PATH` | `~/Library/Application Support/RA-H/db/rah.sqlite` | Database path |
+| `RAH_DB_PATH` | Platform default app-data path | Database path |
 
 For demos or isolated installs:
 
diff --git a/apps/mcp-server-standalone/services/sqlite-client.js b/apps/mcp-server-standalone/services/sqlite-client.js
index 7fa3c8b..65004f2 100644
--- a/apps/mcp-server-standalone/services/sqlite-client.js
+++ b/apps/mcp-server-standalone/services/sqlite-client.js
@@ -7,24 +7,32 @@ const os = require('node:os');
 
 /**
  * Get the database path.
- * Priority: RAH_DB_PATH env var > default app data location
+ * Priority: RAH_DB_PATH env var > SQLITE_DB_PATH env var > platform app data location
  */
-function getDatabasePath() {
-  if (process.env.RAH_DB_PATH) {
-    return process.env.RAH_DB_PATH;
+function getDefaultDbPath() {
+  const homeDir = os.homedir() || process.env.HOME || '~';
+
+  if (process.platform === 'win32') {
+    const appData = process.env.APPDATA || path.join(homeDir, 'AppData', 'Roaming');
+    return path.join(appData, 'RA-H', 'db', 'rah.sqlite');
+  }
+
+  if (process.platform === 'darwin') {
+    return path.join(homeDir, 'Library', 'Application Support', 'RA-H', 'db', 'rah.sqlite');
   }
 
-  // Default: ~/Library/Application Support/RA-H/db/rah.sqlite
   return path.join(
-    os.homedir(),
-    'Library',
-    'Application Support',
+    process.env.XDG_DATA_HOME || path.join(homeDir, '.local', 'share'),
     'RA-H',
     'db',
     'rah.sqlite'
   );
 }
 
+function getDatabasePath() {
+  return process.env.RAH_DB_PATH || process.env.SQLITE_DB_PATH || getDefaultDbPath();
+}
+
 let db = null;
 
 function getExistingColumnNames(db, tableName) {
diff --git a/apps/mcp-server-standalone/skills/onboarding.md b/apps/mcp-server-standalone/skills/onboarding.md
index ce5b095..0266c1d 100644
--- a/apps/mcp-server-standalone/skills/onboarding.md
+++ b/apps/mcp-server-standalone/skills/onboarding.md
@@ -24,7 +24,7 @@ Start with product orientation and goal discovery first.
 Only bring up setup details if the user actually needs them:
 
 1. If they are on local/BYO-key mode, point them to Settings → API Keys.
-2. If they ask about the database location, tell them the default macOS path is `~/Library/Application Support/RA-H/db/rah.sqlite`.
+2. If they ask about the database location, tell them RA-H uses the platform default: macOS `~/Library/Application Support/RA-H/db/rah.sqlite`, Windows `%APPDATA%/RA-H/db/rah.sqlite`, Linux `~/.local/share/RA-H/db/rah.sqlite`.
 3. If API keys are relevant, explain them plainly:
    - **OpenAI** — powers embeddings, semantic retrieval, and extraction-related AI work.
    - **Anthropic** — mainly relevant for compatible runtime paths and local/dev setups.
diff --git a/scripts/dev/setup-local.mjs b/scripts/dev/setup-local.mjs
index 400c7c5..af584cb 100644
--- a/scripts/dev/setup-local.mjs
+++ b/scripts/dev/setup-local.mjs
@@ -6,8 +6,14 @@ function run(command, args) {
   const result = spawnSync(command, args, {
     stdio: 'inherit',
     env: process.env,
+    shell: process.platform === 'win32',
   });
 
+  if (result.error) {
+    console.error(`[setup-local] Failed to run ${command}: ${result.error.message}`);
+    process.exit(1);
+  }
+
   if (result.status !== 0) {
     process.exit(result.status || 1);
   }
diff --git a/src/config/skills/onboarding.md b/src/config/skills/onboarding.md
index ce5b095..0266c1d 100644
--- a/src/config/skills/onboarding.md
+++ b/src/config/skills/onboarding.md
@@ -24,7 +24,7 @@ Start with product orientation and goal discovery first.
 Only bring up setup details if the user actually needs them:
 
 1. If they are on local/BYO-key mode, point them to Settings → API Keys.
-2. If they ask about the database location, tell them the default macOS path is `~/Library/Application Support/RA-H/db/rah.sqlite`.
+2. If they ask about the database location, tell them RA-H uses the platform default: macOS `~/Library/Application Support/RA-H/db/rah.sqlite`, Windows `%APPDATA%/RA-H/db/rah.sqlite`, Linux `~/.local/share/RA-H/db/rah.sqlite`.
 3. If API keys are relevant, explain them plainly:
    - **OpenAI** — powers embeddings, semantic retrieval, and extraction-related AI work.
    - **Anthropic** — mainly relevant for compatible runtime paths and local/dev setups.
diff --git a/src/services/database/sqlite-client.ts b/src/services/database/sqlite-client.ts
index 0026c7b..d966a75 100644
--- a/src/services/database/sqlite-client.ts
+++ b/src/services/database/sqlite-client.ts
@@ -2,6 +2,7 @@ import Database from 'better-sqlite3';
 import fs from 'fs';
 import path from 'path';
 import { DatabaseError } from '@/types/database';
+import { getDatabasePath, getVecExtensionPath } from '@/services/database/sqlite-runtime';
 
 export interface SQLiteConfig {
   dbPath: string;
@@ -115,17 +116,9 @@ class SQLiteClient {
   }
 
   private getSQLiteConfig(): SQLiteConfig {
-    const dbPath = process.env.SQLITE_DB_PATH || path.join(
-      process.env.HOME || '~', 
-      'Library/Application Support/RA-H/db/rah.sqlite'
-    );
-    
-    const vecExtensionPath = process.env.SQLITE_VEC_EXTENSION_PATH || 
-      './vendor/sqlite-extensions/vec0.dylib';
-
     return {
-      dbPath,
-      vecExtensionPath
+      dbPath: getDatabasePath(),
+      vecExtensionPath: getVecExtensionPath()
     };
   }
 
diff --git a/src/services/typescript/sqlite-vec.ts b/src/services/typescript/sqlite-vec.ts
index 8fda92c..92e2243 100644
--- a/src/services/typescript/sqlite-vec.ts
+++ b/src/services/typescript/sqlite-vec.ts
@@ -4,9 +4,11 @@
  */
 
 import Database from 'better-sqlite3';
-import path from 'path';
-import os from 'os';
-import { getDbVectorCapability as getVectorCapability } from '@/services/database/sqlite-runtime';
+import {
+  getDatabasePath as getRuntimeDatabasePath,
+  getDbVectorCapability as getVectorCapability,
+  getVecExtensionPath as getRuntimeVecExtensionPath
+} from '@/services/database/sqlite-runtime';
 
 /**
  * Serialize a float array to binary format for vec0 storage
@@ -35,27 +37,14 @@ export function deserializeFloat32Vector(blob: Buffer): number[] {
  * Get SQLite database path from environment or default location
  */
 export function getDatabasePath(): string {
-  const envPath = process.env.SQLITE_DB_PATH;
-  if (envPath) {
-    return envPath;
-  }
-
-  // Default path: ~/Library/Application Support/RA-H/db/rah.sqlite
-  const homeDir = os.homedir();
-  return path.join(homeDir, 'Library', 'Application Support', 'RA-H', 'db', 'rah.sqlite');
+  return getRuntimeDatabasePath();
 }
 
 /**
  * Get vec extension path from environment or default location
  */
 export function getVecExtensionPath(): string {
-  const envPath = process.env.SQLITE_VEC_EXTENSION_PATH;
-  if (envPath) {
-    return envPath;
-  }
-
-  // Default path relative to project root
-  return path.join(process.cwd(), 'vendor', 'sqlite-extensions', 'vec0.dylib');
+  return getRuntimeVecExtensionPath();
 }
 
 /**
diff --git a/src/tools/other/sqliteQuery.ts b/src/tools/other/sqliteQuery.ts
index 4ed6ac3..b0be719 100644
--- a/src/tools/other/sqliteQuery.ts
+++ b/src/tools/other/sqliteQuery.ts
@@ -2,18 +2,10 @@ import { tool } from 'ai';
 import { z } from 'zod';
 import { exec } from 'child_process';
 import { promisify } from 'util';
-import path from 'path';
+import { getDatabasePath } from '@/services/database/sqlite-runtime';
 
 const execAsync = promisify(exec);
 
-// Get database path (same logic as sqlite-client.ts)
-function getDatabasePath(): string {
-  return process.env.SQLITE_DB_PATH || path.join(
-    process.env.HOME || '~',
-    'Library/Application Support/RA-H/db/rah.sqlite'
-  );
-}
-
 // Security: Only allow SELECT statements
 function isReadOnlyQuery(sql: string): boolean {
   const normalized = sql.trim().toLowerCase();