Add max_position_size to account configs

- DB migration: ALTER TABLE account_configs ADD COLUMN max_position_size INTEGER NOT NULL DEFAULT 0
- Added max_position_size to AccountConfigRow, createAccountConfig, updateAccountConfig in lib/db.ts
- Added maxPositionSize to AccountConfig type in types.ts (0 = no limit)
- GET /api/firms/[id] now returns maxPositionSize per account
- POST /api/firms/[id]/accounts and PUT /api/account-configs/[id] accept maxPositionSize
- Firm settings page: new Max Contracts column (blank = no limit)
- auto-trade: contracts capped at maxPositionSize when > 0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/account-configs/[id]/route.ts

@@ -20,9 +20,10 @@ export async function PUT(
         minTradingDays?: number;
         accountSize?: number;
         maxLoss?: number;
+        maxPositionSize?: number;
     };
 
-    const { prefix, profitTarget, consistency, minDayPnL, minTradingDays, accountSize, maxLoss } = body;
+    const { prefix, profitTarget, consistency, minDayPnL, minTradingDays, accountSize, maxLoss, maxPositionSize } = body;
 
     if (
         typeof prefix !== 'string' || !prefix.trim() ||
@@ -44,6 +45,7 @@ export async function PUT(
             minTradingDays,
             accountSize,
             maxLoss: maxLoss ?? 0,
+            maxPositionSize: maxPositionSize ?? 0,
         });
 
         if (!updated) {

app/api/firms/[id]/accounts/route.ts

@@ -24,9 +24,10 @@ export async function POST(
         minTradingDays?: number;
         accountSize?: number;
         maxLoss?: number;
+        maxPositionSize?: number;
     };
 
-    const { prefix, profitTarget, consistency, minDayPnL, minTradingDays, accountSize, maxLoss } = body;
+    const { prefix, profitTarget, consistency, minDayPnL, minTradingDays, accountSize, maxLoss, maxPositionSize } = body;
 
     if (
         typeof prefix !== 'string' || !prefix.trim() ||
@@ -48,6 +49,7 @@ export async function POST(
             minTradingDays,
             accountSize,
             maxLoss: maxLoss ?? 0,
+            maxPositionSize: maxPositionSize ?? 0,
         });
 
         return NextResponse.json({
@@ -59,6 +61,7 @@ export async function POST(
             minTradingDays: row.min_trading_days,
             accountSize: row.account_size,
             maxLoss: row.max_loss,
+            maxPositionSize: row.max_position_size,
         }, { status: 201 });
     } catch (err) {
         console.error('[POST /api/firms/:id/accounts]', err);

app/api/firms/[id]/route.ts

@@ -31,6 +31,8 @@ export async function GET(
             minDayPnL: a.min_day_pnl,
             minTradingDays: a.min_trading_days,
             accountSize: a.account_size,
+            maxLoss: a.max_loss,
+            maxPositionSize: a.max_position_size,
         })),
     });
 }

app/firms/[id]/settings/page.tsx

@@ -13,6 +13,7 @@ interface AccountConfig {
     minDayPnL: number;
     minTradingDays: number;
     accountSize: number;
+    maxPositionSize: number;
 }
 
 interface FirmConfig {
@@ -49,6 +50,7 @@ function newRow(): RowState {
         minDayPnL: -999,
         minTradingDays: 5,
         accountSize: 50_000,
+        maxPositionSize: 0,
         dirty: true,
         saving: false,
         error: '',
@@ -115,6 +117,7 @@ export default function FirmSettingsPage() {
                 minDayPnL: row.minDayPnL,
                 minTradingDays: row.minTradingDays,
                 accountSize: row.accountSize,
+                maxPositionSize: row.maxPositionSize,
             };
 
             if (row.id < 0) {
@@ -223,13 +226,14 @@ export default function FirmSettingsPage() {
                                 <th className="px-4 py-3 text-left text-xs font-semibold uppercase tracking-wider text-slate-400">Consistency</th>
                                 <th className="px-4 py-3 text-left text-xs font-semibold uppercase tracking-wider text-slate-400">Min Day P&L</th>
                                 <th className="px-4 py-3 text-left text-xs font-semibold uppercase tracking-wider text-slate-400">Min Trading Days</th>
+                                <th className="px-4 py-3 text-left text-xs font-semibold uppercase tracking-wider text-slate-400">Max Contracts</th>
                                 <th className="px-3 py-3 w-32" />
                             </tr>
                         </thead>
                         <tbody>
                             {rows.length === 0 && firmName && (
                                 <tr>
-                                    <td colSpan={7} className="px-4 py-6 text-center text-sm text-slate-400 italic">
+                                    <td colSpan={8} className="px-4 py-6 text-center text-sm text-slate-400 italic">
                                         No account types yet
                                     </td>
                                 </tr>
@@ -354,6 +358,23 @@ export default function FirmSettingsPage() {
                                         />
                                     </td>
 
+                                    {/* Max Contracts */}
+                                    <td className="px-4 py-2.5">
+                                        <input
+                                            type="number"
+                                            className={`${inputCls} w-20`}
+                                            value={row.maxPositionSize === 0 ? '' : row.maxPositionSize}
+                                            placeholder="No limit"
+                                            min={0}
+                                            step={1}
+                                            onChange={(e) =>
+                                                updateRow(row.id, {
+                                                    maxPositionSize: e.target.value === '' ? 0 : Number(e.target.value),
+                                                })
+                                            }
+                                        />
+                                    </td>
+
                                     {/* Actions */}
                                     <td className="px-3 py-2.5">
                                         <div className="flex items-center justify-end gap-1.5">
@@ -402,7 +423,7 @@ export default function FirmSettingsPage() {
 
                             {/* Add row */}
                             <tr className="border-t border-dashed border-slate-200">
-                                <td colSpan={7} className="px-2 py-2">
+                                <td colSpan={8} className="px-2 py-2">
                                     <button
                                         onClick={() => setRows((prev) => [...prev, newRow()])}
                                         className="w-full py-1.5 text-sm text-slate-400 hover:text-slate-600 hover:bg-slate-50 rounded-lg transition-colors"

lib/auto-trade.ts

@@ -41,6 +41,7 @@ function mapFirmConfig(firm: FirmWithAccounts): FirmConfig {
             minTradingDays: a.min_trading_days,
             accountSize: a.account_size,
             maxLoss: a.max_loss,
+            maxPositionSize: a.max_position_size,
         })),
     };
 }
@@ -124,7 +125,8 @@ export async function runTrade(action: 'Buy' | 'Sell', symbol: string) {
         const totalProfit = dailyPnL.reduce((sum, d) => sum + d.pnl, 0);
         const target = computeDailyTarget(cfg.profitTarget, cfg.consistency, totalProfit, dailyPnL);
 
-        const contracts = Math.max(1, Math.ceil(target.amount / 1000));
+        const rawContracts = Math.max(1, Math.ceil(target.amount / 1000));
+        const contracts = cfg.maxPositionSize > 0 ? Math.min(rawContracts, cfg.maxPositionSize) : rawContracts;
         const fill = await client.sendOrder(acc.id, contract.name, contracts, action, 'Market');
 
         // Wait briefly for the cash balance WebSocket update to reflect entry commission

lib/db.ts

@@ -43,6 +43,13 @@ try {
     // Column already exists
 }
 
+// Migration: add max_position_size column (0 = no limit)
+try {
+    db.exec('ALTER TABLE account_configs ADD COLUMN max_position_size INTEGER NOT NULL DEFAULT 0');
+} catch {
+    // Column already exists
+}
+
 // Seed default firms if empty
 const firmCount = (db.prepare('SELECT COUNT(*) as count FROM firms').get() as { count: number }).count;
 if (firmCount === 0) {
@@ -77,6 +84,7 @@ export interface AccountConfigRow {
     min_trading_days: number;
     account_size: number;
     max_loss: number;
+    max_position_size: number;
 }
 
 export interface FirmRow {
@@ -129,11 +137,12 @@ export function createAccountConfig(firmId: number, data: {
     minTradingDays: number;
     accountSize: number;
     maxLoss: number;
+    maxPositionSize: number;
 }): AccountConfigRow {
     const stmt = db.prepare(
-        'INSERT INTO account_configs (firm_id, prefix, profit_target, consistency, min_day_pnl, min_trading_days, account_size, max_loss) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
+        'INSERT INTO account_configs (firm_id, prefix, profit_target, consistency, min_day_pnl, min_trading_days, account_size, max_loss, max_position_size) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)'
     );
-    const result = stmt.run(firmId, data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss);
+    const result = stmt.run(firmId, data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, data.maxPositionSize);
     return db.prepare('SELECT * FROM account_configs WHERE id = ?').get(result.lastInsertRowid) as AccountConfigRow;
 }
 
@@ -150,12 +159,13 @@ export function updateAccountConfig(id: number, data: {
     minTradingDays: number;
     accountSize: number;
     maxLoss: number;
+    maxPositionSize: number;
 }): boolean {
     const result = db.prepare(`
         UPDATE account_configs
-        SET prefix = ?, profit_target = ?, consistency = ?, min_day_pnl = ?, min_trading_days = ?, account_size = ?, max_loss = ?
+        SET prefix = ?, profit_target = ?, consistency = ?, min_day_pnl = ?, min_trading_days = ?, account_size = ?, max_loss = ?, max_position_size = ?
         WHERE id = ?
-    `).run(data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, id);
+    `).run(data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, data.maxPositionSize, id);
     return result.changes > 0;
 }
 

types.ts

@@ -5,7 +5,8 @@ export interface AccountConfig {
     minDayPnL: number;
     minTradingDays: number;
     accountSize: number;
-    maxLoss: number;  // 0 = no limit; positive = account is "Dead" when loss exceeds this
+    maxLoss: number;          // 0 = no limit; positive = account is "Dead" when loss exceeds this
+    maxPositionSize: number;  // 0 = no limit; positive = max contracts per trade
 }
 
 export interface FirmConfig {