Are Perps and Polymarket US the same market data?

No. Perpetual futures live under /v1/polymarket/perps (instruments, tickers, klines, book, trades, leaderboard), and the US exchange lives under /v1/polymarket/us (events, event, market, series). They have their own ids, fields and rules, so the route groups keep them separate. Polymarket US is a different exchange from the main Polymarket event market.