Vest platform: a client for Vest Markets, traded on a session the extension relays

Vest (next.vestmarkets.com) is a perps prop firm: index, metal and energy
perps on CME hours, plus stocks, FX and crypto. It joins as a fourth
platform, 'vest', on the DXtrade engine paths. Those are now keyed by
isNotionalPlatform() instead of === 'dxtrade': the firm's own symbols,
percent fees, notional sizing from volatility, and a scheduler lane of its
own.

- Login is relayed, not stored. Vest signs people in with Google through
  Privy and renews the session with a device key the browser won't export.
  Extension 0.17.0's vest-relay.js reads the token the Vest app renews for
  itself (~15 min). It renews nothing, so the tab is never logged out. The
  background script posts that token to POST /api/vest/session, which holds
  it in memory only. With no Vest tab open on a machine that trades Vest,
  the extension opens one.
- The firm's credential is the Vest login's wallet address. The dashboard's
  form offers the relayed wallet with one click.
- VestClient (lib/vest-class.ts), mapped from the web app's traffic and code
  since Vest publishes no API:
  - Reads the capital accounts, balances (free amount plus position
    collateral), positions and open orders with the user token.
  - Mints per-account tokens for orders and transactions.
  - Names accounts for their rules (V50K-E-D3-T10-34, V50K-F-D3-34,
    V25K-I-7) so account-type prefixes can match.
  - Takes Vest's own max-drawdown and daily-loss floors. dayStartBalance =
    floor + the type's limit, so the engine's room is never more than
    Vest's.
  - Uses each symbol's taker fee and margin rate from exchangeInfo, and
    hourly volatility over in-session hours only.
  - Places take-profit and stop as position legs, which Vest cancels as an
    OCO pair.
- Daily P&L and fund rows come from /v3/transactions by Vest's 20:00 ET
  day. A books check holds an account, naming the transaction types, when
  the balance and the transactions disagree.
- scripts/check-vest.mjs (in npm run check): Vest's day across DST, account
  names, parsing, volatility gaps, market hours, the session store.

Not yet run against Vest with a live session: the order and exit bodies
come from the app's code, and the transaction classification from its enum.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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

@@ -16,7 +16,9 @@ type Params = { params: Promise<{ id: string }> };
  *  and login domain are set on the master, per firm). TopstepX firms need the
  *  API key; username is optional for now (the loginKey call still wants it,
  *  so the client sits idle with a clear error until one is added) and
- *  password is unused. */
+ *  password is unused. Vest firms need the login's wallet address in the API
+ *  key slot: Vest's session is relayed by the extension from a signed-in Vest
+ *  tab (lib/vest-session.ts), and the address says whose to trade. */
 export async function PUT(req: NextRequest, { params }: Params) {
     const { id } = await params;
 
@@ -33,7 +35,9 @@ export async function PUT(req: NextRequest, { params }: Params) {
             ? 'apiKey is required for a TopstepX firm'
             : firm.platform === 'dxtrade'
                 ? 'username and password are required for a DXtrade firm'
-                : 'username and password are required';
+                : firm.platform === 'vest'
+                    ? 'a Vest firm needs the wallet address of the Vest login (0x followed by 40 hex characters)'
+                    : 'username and password are required';
         return NextResponse.json({ error }, { status: 400 });
     }