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Arbitrage Signal Stream

Artery ships a streaming arbitrage detector: every 5s the system recomputes spreads for every multi-provider event, applies per-provider fees, and pushes a signal whenever the net edge crosses a profitable threshold.

Channel layout

Channel	What
`artery:stream:event:<universalId>`	Full spread snapshot every time a leg's mid moves ≥ 0.5¢
`artery:stream:arbitrage:<universalId>`	Only when net edge after fees ≥ 50 bps; emitted on every tick the condition holds

Both channels carry the standard event envelope:

json{
  "type": "event",
  "subscription_id": "uuid",
  "data": {
    "type": "event.arbitrage",
    "marketId": "evt_e8b415bf-...",
    "payload": { /* see below */ },
    "receivedAt": 1714928400000
  }
}

Arbitrage payload

json{
  "universalId": "evt_e8b415bf-be26-4766-9680-998549fe01b1",
  "fetchedAt": "2026-05-09T05:58:05.037Z",
  "buyProvider": "polymarket",
  "buyMarketId": "0xa8aceb0fb04828602057be...",
  "buyMid": 0.0095,
  "sellProvider": "kalshi",
  "sellMarketId": "KXBTCD-26MAY0917-T69999.99",
  "sellMid": 0.030,
  "grossEdge": 0.0205,
  "netEdge": 0.0203,
  "annualizedReturn": 7.41
}

Field	Meaning
`buyProvider` / `buyMid`	Cheapest YES — execute the BUY leg here
`sellProvider` / `sellMid`	Richest YES — execute the SELL leg here
`grossEdge`	Raw mid-to-mid difference (sellMid − buyMid)
`netEdge`	After both legs' round-trip taker fees
`annualizedReturn`	netEdge × 365 — for ranking only, not actual yield

Quickstart

List the universal events you want to watch

bashTOKEN="art_live_..."
curl 'https://api.artery.questflow.ai/v1/events?underlying=BTC&min_providers=2' \
  -H "Authorization: Bearer $TOKEN" \
  | jq -r '.events[].universalId'

Subscribe via WebSocket

jsimport WebSocket from 'ws';
const TOKEN = process.env.ART_TOKEN;
const eventIds = [/* from step 1 */];
const ws = new WebSocket(`wss://api.artery.questflow.ai/v1/stream?token=${TOKEN}`);
 
ws.on('open', () => {
  const channels = eventIds.flatMap((id) => [
    `artery:stream:arbitrage:${id}`,
    `artery:stream:event:${id}`,
  ]);
  ws.send(JSON.stringify({ type: 'subscribe', channels }));
});
 
ws.on('message', (raw) => {
  const m = JSON.parse(raw.toString());
  if (m.type === 'pong') return;
  if (m.data?.type === 'event.arbitrage') {
    const p = m.data.payload;
    console.log(
      `BUY ${p.buyProvider} ${p.buyMarketId} @ ${p.buyMid} → ` +
      `SELL ${p.sellProvider} ${p.sellMarketId} @ ${p.sellMid}  ` +
      `net=${(p.netEdge * 100).toFixed(2)}c`
    );
  }
});

Tune the threshold
Default minimum net edge for emission is 50 bps. To see all positive signals (including marginal):
```
bashcurl "https://api.artery.questflow.ai/v1/events/<id>/arbitrage" \
  -H "Authorization: Bearer $TOKEN"
```
The /arbitrage REST endpoint uses threshold 0 — it surfaces every positive net edge, even if too small to push to the stream.

Fee schedule

The signal engine deducts a conservative round-trip taker fee per provider:

Provider	Default `takerBps`	Override env
Polymarket	20	`ART_FEES_POLYMARKET_TAKER_BPS`
Kalshi	50	`ART_FEES_KALSHI_TAKER_BPS`
Hyperliquid HIP-4	14	`ART_FEES_HYPERLIQUID_HIP4_TAKER_BPS`
Hyperliquid Perp	14	`ART_FEES_HYPERLIQUID_PERP_TAKER_BPS`
Hyperliquid DEX	30	`ART_FEES_HYPERLIQUID_DEX_TAKER_BPS`

Set in your deployment env to tighten or loosen the filter:

bashART_FEES_KALSHI_TAKER_BPS=25 pnpm --filter @artery/api dev

What the signals don't account for

Warning

The net edge is upper-bound — many real-world frictions can erode it:

Slippage — if you're moving size, the displayed mid won't fill at that price
Funding rate exposure for leveraged positions (HL Perp / HIP-3)
Settlement risk — UMA disputes, Kalshi force-majeure clauses
Latency — the snapshot was true 5s ago; market may have moved
KYC / geo restrictions — can you actually trade on both legs?

Treat these as triggers for further analysis, not "press 'execute' to win".

Settlement consensus tracking

Each universal event also exposes its historical settlement record across providers:

bashcurl "https://api.artery.questflow.ai/v1/events/<id>/settlement" -H "Authorization: Bearer $TOKEN"

json{
  "universalId": "evt_...",
  "records": [
    { "provider": "polymarket", "polarity": "yes", "resolvedAt": "..." },
    { "provider": "kalshi",     "polarity": "yes", "resolvedAt": "..." }
  ],
  "consensusScore": 1.0
}

A consensus score < 1.0 means the linked markets disagreed on resolution — a flashing red indicator that this kind of event has structural settlement risk and any "arbitrage" should be sized accordingly.

Arbitrage Signal Stream#

Channel layout#

Arbitrage payload#

Quickstart#

Fee schedule#

What the signals don't account for#

Settlement consensus tracking#

See also#