{"uid":"cap_S527ocu_KP8gJ-AxynmdY","slug":"perp-mark-index-premium-calculator-115bf5af","name":"Perp Mark Index Premium Calculator","description":"Premium (mark-index)/index in bps. Call when monitoring perp basis without live feeds (caller prices). Returns premium_bps as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.","url":"https://api.delx.ai/api/v1/x402/perp-premium","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"mark":{"type":"number","description":"Perp mark price"},"index":{"type":"number","description":"Index price"}}},"responseSchema":{"type":"json","example":{"schema":"delx/util-perp-premium/v1","premium_bps":50}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_-c58L9Qp28-rYAP_YVXTD","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the perpetual futures basis premium as (mark - index) / index in basis points from caller-supplied prices","exampleAgentPrompt":"What's the perp premium in basis points if the mark price is 68,450 and the index price is 68,200?","exampleUseCases":[{"title":"Basis check before placing perp trade","prompt":"Before I open a long perp position, can you tell me the premium in bps if my mark price is 3,180 and the index is 3,150?"},{"title":"Monitoring contango in automated strategy","prompt":"My strategy sees a mark of 29,050 and an index of 28,900 on BTC perps — what's the current premium in basis points so I can decide whether to arb?"},{"title":"Post-fill basis attribution","prompt":"After my fills, mark settled at 1,845.50 and index was 1,842.00 — calculate the perp premium in bps for my trade log."}],"resultDescription":"Returns a deterministic JSON object containing premium_bps, the calculated (mark - index) / index value expressed in basis points, with no external data dependencies","failureModes":["Missing mark or index field returns a 4xx validation error","index price of zero causes division-by-zero error","Non-numeric values for mark or index result in schema validation failure","Payment failure via x402 returns 402 Payment Required before computation occurs"],"whenToPreferThis":"Choose this endpoint when you already have mark and index prices in hand and need a quick, deterministic basis-points computation without subscribing to live market feeds or managing API keys. It is ideal for advisory analytics, trade logging, or pre-trade basis checks inside automated agent workflows where capital decisions remain with the caller.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:01:57.685Z","isFirstParty":false}