Streams (SSE)

Server-Sent Events are the simplest live feed: one HTTP request that never ends, readable with EventSource in a browser or curl -N on a shell. No key. TRUE keeps one shared poller per market for every subscriber, so your connection costs the venue nothing extra.

curl -N "https://app.truefinance.ai/api/perps-dex/stream?market=BTCUSDC&kline=1m,15m"

Events

Each event is an event: line and a JSON data: line. Everything is pushed only when it changed; the current state of each arrives on connect, so you can render before the first live change.

event	payload	cadence
bbo	best bid and offer with sizes	on change, polled at 350 ms
orderbook	full book, depth 60, {bids:{price:size}, asks:{…}}	on change, polled at 600 ms
stats	the 24h stats row	on change, about once a second
mark	{market, mark_price}, the oracle mark	on change; the oracle moves about once a second
trades	array of new fills only, never a replay	polled at 1 s
kline	a server built bar for each interval in &kline=…; closed:true when it rolled	only when the bar changed
block	chain head: block height and settle cadence	on change
tape	venue fill counter {trades_24h, trades_today}	on change
hb	heartbeat, {}	every 15 s, on every stream

Kline intervals: 1s 1m 5m 15m 1h 4h 1d. A bar is {market, interval, start, open, high, low, close, volume, trades, closed, filled}. Bars are built from the oracle mark with volume carried from real fills, so a market with no trades still produces a moving bar.

Trades are deltas only: load the initial tape over REST, then append.

To receive only some events, add &events= with a comma separated list, for example &events=mark,kline for a chart. Without it you get every event; hb is always sent.

The list feed

stats for every market in one event, mark as one bundle {marks:{SYM:px}, ts, src:"pyth"|"oracle"} (oracle when Pyth has gone quiet) for every market, and tape. The stats bundle churns about once a second because 24h volume is a rolling window; the marks bundle is pushed only when a mark moved.

Reconnecting

The stream sends retry: 3000, so EventSource reconnects on its own after 3 s. Reconnect with backoff yourself if you use a raw HTTP client: 1 s doubling to 15 s. A reconnect gets the full current state again.

A quiet market can go minutes without a data event, so do not judge the connection by those. The hb event arrives every 15 s on every stream: if 40 s pass with no event at all, the connection is dead (a half-open socket after a network change looks open); close it and reconnect. During a deploy the server ends streams cleanly and answers new ones with 503 for a moment; back off and retry.