{"uid":"cap_SM0qKo9mVsAzieRcaP3o4","slug":"numeral-systems-roman-numeral-converter-f48b9e7d","name":"Numeral Systems – Roman Numeral Converter","description":"Convert between integers (1–3999) and Roman numerals in either direction — a digit string is encoded to Roman, a Roman numeral is decoded to an integer. Non-canonical numerals (IIII, IC) are rejected.","url":"https://numeral.openverbs.com/v1/roman","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["value"],"properties":{"value":{"type":"string","maxLength":32,"minLength":1,"description":"An integer 1–3999, or a Roman numeral like \"MCMXCIV\"."}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_7kQmH4ej-WpH5GlMIfZZA","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Converts between Arabic integers (1–3999) and Roman numerals bidirectionally via a single POST call","exampleAgentPrompt":"Convert 1994 to its Roman numeral equivalent — the value is 1994.","exampleUseCases":[{"title":"Display year in Roman numerals","prompt":"What's 2024 written as a Roman numeral? I want to engrave it on a trophy."},{"title":"Decode Roman numeral inscription","prompt":"I found the inscription MCMXCIX on a building — what year does that actually represent?"},{"title":"Automate Roman numeral formatting","prompt":"I need to convert the number 399 to a Roman numeral for a chapter heading in my book."}],"resultDescription":"Returns the converted value: if an Arabic integer was submitted, the response contains the corresponding Roman numeral string; if a Roman numeral was submitted, the response contains the corresponding integer — along with any relevant metadata about the conversion.","failureModes":["Input integer out of range (must be 1–3999): returns validation error","Invalid Roman numeral string (malformed sequence): returns parsing error","Empty or missing value field: returns required field error","Value exceeds 32 character maxLength: returns validation error","Non-integer string submitted as numeric input: returns type error"],"whenToPreferThis":"Use this endpoint when you need a quick, reliable bidirectional conversion between standard Arabic integers and classical Roman numerals (range 1–3999). Ideal for formatting chapter numbers, years, engraving text, clock faces, or decoding historical inscriptions. Prefer this over a general math API when the specific Roman numeral representation is the desired output.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:34:21.387Z","isFirstParty":false}