GET /basis/{coin}

$0.02 USDC Powered by Chainlink

Two different measurements for one market:

perp_premium_bps, the perp premium: Hyperliquid’s mark price against Hyperliquid’s own oracle price. This is the premium that funding follows, and the one direction, signal and interpretation describe.
oracle_divergence_bps: Hyperliquid’s oracle (a weighted median of exchange spot prices) against Chainlink’s spot price on Arbitrum. Both are spot references, so this measures how far two spot sources disagree, not funding pressure.

basis_bps and basis_pct are kept for old clients and are deprecated. They carry the oracle vs Chainlink gap, as they always have, not the perp premium.

Request

GET https://api.cerebruspulse.xyz/basis/{coin}

Path Parameters

Parameter	Type	Required	Description
`coin`	string	Yes	Token symbol (`BTC`, `ETH`, `SOL`). It needs a Chainlink feed in the snapshot (38 on 2026-09-24, BTC, ETH, SOL, LINK, ARB, DOGE, AVAX, NEAR, AAVE, UNI, OP and PEPE among them) and a Hyperliquid market. An unsupported coin gets a 400 listing the available ones, not charged.

Response

All prices are USD per single token, including for 1000-token markets such as PEPE.

Field	Type	Description
`endpoint`	string	`basis`
`coin`	string	The symbol, upper-case
`market_symbol`	string	Hyperliquid’s name for the market (`kPEPE` for PEPE)
`price_unit`	string	`1 <coin>`: every price here is per token
`timestamp_iso`	string	When the response was computed (UTC)
`basis.hl_mark_px`	number	Hyperliquid mark price
`basis.hl_oracle_px`	number	Hyperliquid oracle price
`basis.chainlink_spot_px`	number	Chainlink spot price (Arbitrum)
`basis.perp_premium_bps`	number	Perp premium: `(hl_mark_px − hl_oracle_px) / hl_oracle_px × 10000`
`basis.premium_index_bps`	number \| null	Hyperliquid’s own premium sample (impact prices against the oracle) in basis points, which its funding averages
`basis.oracle_divergence_bps`	number \| null	`(hl_oracle_px − chainlink_spot_px) / chainlink_spot_px × 10000`; null, with the warning `chainlink_price_implausible`, when the two differ by more than 2×
`basis.basis_bps`	number \| null	Deprecated: the same value as `oracle_divergence_bps` (see `meta.deprecated`)
`basis.basis_pct`	number \| null	Deprecated: `basis_bps` in percent
`basis.direction`	string	`hl_premium`, `hl_discount` or `aligned`: the sign of `perp_premium_bps`
`basis.signal`	string	A label for the premium’s size and sign: `neutral` (−10 to 10 bps), `mildly_bullish` (10 to 50), `mildly_bearish` (−50 to −10), `bearish_contrarian` (above 50), `bullish_contrarian` (below −50). A description of the premium, not a recommendation
`basis.interpretation`	string	The label in words
`meta`	object	Common metadata (Response Schemas)
`meta.offering`	string	`pulse_basis`
`meta.basis_definition`	string	The two definitions above, as text
`meta.deprecated`	object	Fields kept for old clients, each with what to read instead
`meta.chainlink_data_age_seconds`	number \| null	Age of the Chainlink snapshot. Above 120 seconds, `meta.warning` is `stale_chainlink_data`
`meta.chainlink_round_age_seconds`	number \| null	Age of the Chainlink round behind the price, when the snapshot records it; null otherwise
`meta.chainlink_feed_network`	string	`arbitrum`
`meta.hl_source`	string	`mark_and_oracle`

Example

GET /basis/BTC: real engine output on market data captured at 2026-09-24 17:05 UTC. Lists are cut to 3 items. Live responses may also carry meta.disclaimer, which the gateway adds.

{
  "endpoint": "basis",
  "coin": "BTC",
  "market_symbol": "BTC",
  "price_unit": "1 BTC",
  "timestamp_iso": "2026-09-24T17:05:00Z",
  "basis": {
    "hl_mark_px": 84517,
    "hl_oracle_px": 84539,
    "chainlink_spot_px": 84501.01946422,
    "perp_premium_bps": -2.6,
    "premium_index_bps": -4.61,
    "oracle_divergence_bps": 4.49,
    "basis_bps": 4.49,
    "basis_pct": 0.0449,
    "direction": "hl_discount",
    "signal": "neutral",
    "interpretation": "Perp trades at its oracle price: no significant premium"
  },
  "meta": {
    "provider": "Cerebrus Pulse",
    "offering": "pulse_basis",
    "execution_ms": 0,
    "basis_definition": "perp_premium_bps: Hyperliquid mark vs its oracle (perp premium), which direction, signal and interpretation describe; oracle_divergence_bps: Hyperliquid oracle vs Chainlink spot, which basis_bps has always carried",
    "deprecated": {
      "basis.basis_bps": "the Hyperliquid oracle vs Chainlink spot gap, not the perp premium; read basis.oracle_divergence_bps, or basis.perp_premium_bps for the premium",
      "basis.basis_pct": "basis.basis_bps / 100; read basis.oracle_divergence_bps"
    },
    "data_age_seconds": 60,
    "chainlink_data_age_seconds": 55.6,
    "chainlink_round_age_seconds": null,
    "chainlink_feed_network": "arbitrum",
    "hl_source": "mark_and_oracle",
    "sources": [
      {
        "name": "Hyperliquid",
        "url": "https://hyperliquid.xyz"
      },
      {
        "name": "Chainlink Data Feeds (Arbitrum One)",
        "url": "https://data.chain.link"
      }
    ]
  }
}

Errors

Status	Reason
400	No Chainlink feed or Hyperliquid market for the coin, or no snapshot yet (not charged)
402	Payment required (the standard x402 flow)
429	Rate limit exceeded
503	Service disabled, payments down, or an upstream feed is missing or stale; no price is quoted
504	Engine timeout (not charged)