{"uid":"cap_G6mDFzmGzZC_vtGYZp3hs","slug":"sindri-physical-constants-lookup-9a3b5201","name":"Sindri Physical Constants Lookup","description":"Lookup of standard physical constants (speed of light, gravitational constant, Planck constant, elementary charge, Avogadro number, Boltzmann constant, gas constant, electron mass) with exact published CODATA values.","url":"https://x402.outpimp.com/physicalConstants","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"constant":{"enum":["speedOfLight","gravitationalConstant","planckConstant","elementaryCharge","avogadroNumber","boltzmannConstant","gasConstant","electronMass"],"type":"string","description":"Which constant to look up."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_RgAttNxsnpYFCZsDXi9yk","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the exact CODATA-published value of a named fundamental physical constant (e.g. speed of light, Planck constant, Boltzmann constant).","exampleAgentPrompt":"What is the exact CODATA value of the Boltzmann constant? Look it up using the physicalConstants endpoint with 'boltzmannConstant'.","exampleUseCases":[{"title":"Physics homework unit verification","prompt":"What is the exact value of the speed of light? I need the precise CODATA figure for my physics problem set."},{"title":"Chemistry calculation with Avogadro's number","prompt":"Can you look up the exact Avogadro number for me? I need the precise value to finish my stoichiometry calculation."},{"title":"Quantum mechanics formula with Planck constant","prompt":"What's the exact published CODATA value of the Planck constant? I'm computing photon energies and need maximum precision."}],"resultDescription":"Returns the exact CODATA-published numeric value (and likely units) for the requested physical constant — one of: speedOfLight, gravitationalConstant, planckConstant, elementaryCharge, avogadroNumber, boltzmannConstant, gasConstant, or electronMass.","failureModes":["Invalid or unsupported constant name — only the eight enumerated constants are accepted","Missing 'constant' field in request body returns validation error","Network timeout or service unavailability returns HTTP error"],"whenToPreferThis":"Use this endpoint when you need a precise, authoritative CODATA value for one of the eight supported fundamental physical constants and want a deterministic, reproducible lookup rather than relying on a language model's potentially imprecise recall. Ideal for scientific computing, formula verification, or educational tools.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T18:32:03.576Z","isFirstParty":false}