Basis & carry API

What this is

Funding rates are an income stream. The trade is to be long the cheap side, short the expensive side, neutralize price exposure, and collect the spread. This API exposes the inputs (per-symbol cross-venue spread, oracle-family disclosure, volume-weighted spread) and a premium pre-computed signal endpoint that ranks the cleanest opportunities after filtering same-source pairs and thin books.

• Systematic carry desks running cross-venue delta-neutral books.
• Agents executing carry policies who need a one-call 'is there a trade right now?' answer.
• Researchers comparing funding-arb returns vs basis-trade returns vs the underlying volatility.
• RWA-focused traders looking at Hyperliquid HIP-3 perp basis vs cash markets.

Endpoints

The endpoints below are live on api.usenami.io. Prices are per call in USDC, settled on Base via x402 — no signup, no API key, no monthly minimum. Full spec at /.well-known/x402.json.

Often used alongside (same API, same pricing model):

Quickstart

The premium funding-signal route returns ranked opportunities; the cheaper routes return the raw inputs. The free endpoints (/v1/health, /v1/venues/list, /v1/venues/health, and the preview routes) return without payment so you can validate connectivity before any USDC moves.

# premium one-call signal — already filtered, ranked
curl -X POST <x402-pay> https://api.usenami.io/v1/perp/arbitrage/funding-signal

# typical response (truncated)
{
  "as_of": "...",
  "opportunities": [
    {
      "symbol": "BTC-PERP",
      "long_venue":  "binance",       "long_rate_apr":  4.2,
      "short_venue": "hyperliquid",   "short_rate_apr": -88.0,
      "net_apr": 92.2, "vw_size_usd": 850000,
      "same_oracle_family": false,
      "stale_data_flag":    false
    },
    ...
  ]
}

# DIY path — same answer, cheaper, more lifting
spread     = pay("/v1/perp/funding-spread")     # $0.001
families   = pay("/v1/perp/oracle-families")    # $0.001
vw         = pay("/v1/perp/vw-spread")           # $0.003
# join, filter, rank — $0.005 total but you control the logic

What you actually get

The honest disclaimer: The funding-signal endpoint is our judgment call, not a guarantee. We rank by net APR after oracle-family and minimum-volume filters; we don't model execution slippage, withdrawal time, or funding-payment timing — your model does. The cheaper raw routes give you all the inputs to build a stricter ranker if ours doesn't fit your risk view.

FAQ