Polymarket Replaced RTDS: Migrating to PolyBolt

If your bot streams spot prices to decide anything — and on crypto Up/Down markets, most do — this touches you. Six things changed at once, and the awkward part is that several of them fail quietly: you stay connected, you just stop getting the prices you think you are getting.

The six breaking changes

Channel mapping

Connecting

Authenticate on the open connection first, wait for confirmation, then subscribe. Reference-price channels reject unauthenticated subscriptions.

{
  "op": "auth",
  "rid": "a1",
  "auth": {
    "apiKey": "<api key>",
    "secret": "<api secret>",
    "passphrase": "<api passphrase>"
  }
}

Those same credentials are the ones you derive for CLOB trading — key, secret and passphrase together. If you have never created them, the endpoint guide covers the L1/L2 flow.

Three things PolyBolt gives you that RTDS did not

• A snapshot on every subscribe. Each subscription returns the preceding two minutes of prices with snapshot: true, possibly empty. Seed local state from it, then apply live updates. Under RTDS a quiet symbol just gave you silence and you had no idea whether you were connected or simply between ticks.
• A dense seq and a dropped counter. You can finally detect gaps. RTDS had no sequence at all, so a missed message was invisible. Track seq per channel and treat any jump as a resync trigger.
• Typed close codes instead of raw 1006: 4001 auth, 4002 slow consumer, 4003 draining, 4008 policy. A 4002 means you are too slow to drain the socket — that is a consumer bug, not a network problem, and reconnecting will not fix it.

Connection limits

RTDS published none. PolyBolt does, and breaching any of them closes the socket with 4008:

64 subscriptions is the one to plan around. If you track BTC, ETH and SOL across spot and TWAP that is six, so there is plenty of headroom for a crypto bot — but a system that fans out across the equity catalogue will hit it.

Migrating a bot, in order

1. Derive CLOB API credentials if you do not have them. RTDS was public; PolyBolt is not. This is the step that blocks everything else.
2. Change the URL to wss://ws-live-v2.polymarket.com/ws.
3. Delete your client heartbeat. The 5-second PING loop is not just unnecessary, it is now noise. The server pings you every 25 seconds.
4. Rewrite subscribe frames — action → op, topic → channel, and filter becomes a JSON object rather than a string.
5. Fix every symbol: btcusdt and btc/usd both become btcusd. Lowercase, USD.
6. Handle the snapshot frame so you do not treat two minutes of backfill as live ticks.
7. Add seq gap detection and resync on a jump.
8. Recalibrate anything tuned to Binance prices. The source is Pyth now.

What this does not change

Worth being precise, because it is easy to over-migrate. The CLOB market and user channels are untouched. wss://ws-subscriptions-clob.polymarket.com/ws/market still carries order book and price updates, still wants a client PING every 10 seconds, and still hides best_bid_ask, new_market and market_resolved behind custom_feature_enabled. Only reference prices moved. Details in the WebSocket guide.

And the deeper limitation is unchanged too: a stream gives you prices from the moment you connect. It cannot tell you what the book looked like last Tuesday. Polymarket returns 404 for a resolved market's book and keeps only about one point a minute of price history, which is why backtesting needs an archive recorded while the markets ran. See how Up/Down markets work or look up a specific market in the market lookup.