| name | aster-api-websocket-v3 |
| description | WebSocket market + user data streams for Aster Futures API v3. Subscription model, stream names, listenKey. Use when implementing real-time market or user events (orders, balance, positions). listenKey = signed; see aster-api-auth-v3. |
Aster API WebSocket
Base: wss://fstream.asterdex.com. Raw: /ws/<streamName>. Combined: /stream?streams=name1/name2/... → {"stream":"<name>","data":<payload>}. Stream names lowercase (e.g. btcusdt).
Limits: 24h; ping 5 min → pong within 15 min; 10 msg/s; max 200 streams.
Market: subscribe / unsubscribe
JSON: Subscribe {"method":"SUBSCRIBE","params":["btcusdt@aggTrade","btcusdt@depth"],"id":1} → {"result":null,"id":1}. Unsubscribe: UNSUBSCRIBE + params. List: LIST_SUBSCRIPTIONS. id = unsigned int.
Stream names (market)
| Stream | Description |
|---|
<symbol>@aggTrade | Aggregate trades (100ms) |
<symbol>@depth | Diff. book depth (250/500/100ms: @depth@500ms, @depth@100ms) |
<symbol>@depth5, @depth10, @depth20 | Partial book depth |
<symbol>@kline_<interval> | Kline (e.g. 1m, 1h); interval as in REST |
<symbol>@markPrice, <symbol>@markPrice@1s | Mark price (3s or 1s) |
!markPrice@arr, !markPrice@arr@1s | All symbols mark price |
<symbol>@miniTicker | 24h mini ticker (500ms) |
!miniTicker@arr | All mini tickers (1000ms) |
<symbol>@ticker | 24h ticker (500ms) |
!ticker@arr | All tickers (1000ms) |
<symbol>@bookTicker | Best bid/ask (real-time) |
!bookTicker | All book tickers |
<symbol>@forceOrder | Liquidation snapshot (1000ms) |
!forceOrder@arr | All liquidations |
User data stream
- Start:
POST /fapi/v3/listenKey (signed) → { "listenKey": "..." }. If account already has active listenKey, same key returned and validity extended 60 min.
- Connect:
wss://fstream.asterdex.com/ws/<listenKey>.
- Keepalive:
PUT /fapi/v3/listenKey (signed) at least every <60 min (e.g. every 30 min).
- Close:
DELETE /fapi/v3/listenKey (signed).
User data events are not guaranteed in order during heavy load; order updates by event time E.
Events: ACCOUNT_UPDATE (balance/position), ORDER_TRADE_UPDATE, ACCOUNT_CONFIG_UPDATE (leverage, multi-asset, position mode), MARGIN_CALL, listenKeyExpired.
Order book sync (depth stream)
- Connect to
btcusdt@depth (or combined).
- Buffer incoming events.
- Get snapshot:
GET /fapi/v3/depth?symbol=BTCUSDT&limit=1000.
- Drop events with
u < snapshot lastUpdateId.
- First valid event:
U ≤ lastUpdateId and u ≥ lastUpdateId.
- Then each event’s
pu must equal previous event’s u; else re-sync from step 3.
- Quantity in events is absolute; quantity 0 means remove that price level.
Payload shapes: reference.md.
