{"uid":"cap_4BLZDd8kmsO9klvCmjUt0","slug":"playfair-cipher-encoder-decoder-4a7ec375","name":"Playfair Cipher Encoder/Decoder","description":"Playfair cipher encode or decode with a keyword; shows the 5x5 square and the digraphs. I and J are merged.","url":"https://text-ciphers.x402tookit.com/playfair?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["text","key"],"properties":{"key":{"type":"string","description":"Keyword, e.g. PLAYFAIR EXAMPLE"},"mode":{"type":"string","description":"encode (default) or decode"},"text":{"type":"string","description":"Plain or cipher text (up to 1000 characters)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"key":{"type":["null","string"]},"asOf":{"type":["null","string"]},"mode":{"type":["null","string"]},"output":{"type":["null","string"]},"secure":{"type":["boolean","null"]},"source":{"type":["null","string"]},"square":{"type":["array","null"],"items":{"type":"string"}},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"digraphsIn":{"type":["array","null"],"items":{"type":"string"}},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"outputGrouped":{"type":["null","string"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_XkPRwWGB6UplAmuN_z1sn","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Encodes or decodes text using the Playfair cipher with a given keyword, returning the 5x5 key square and step-by-step digraph pairs.","exampleAgentPrompt":"Can you encode the message 'HIDE THE GOLD IN THE TREE STUMP' using the Playfair cipher with the keyword 'MONARCHY' and show me the 5x5 square and the digraph pairs?","exampleUseCases":[{"title":"Encoding a secret message for a puzzle","prompt":"Encode the text 'MEET AT DAWN' using the Playfair cipher with the keyword 'PLAYFAIR EXAMPLE' and show me the resulting ciphertext along with the key square and digraphs."},{"title":"Decoding a received Playfair ciphertext","prompt":"I received this Playfair-encoded message: 'BMODZBXDNABEKUDMUIXMMOUVIF' — can you decode it using the keyword 'PLAYFAIR' and show me the step-by-step digraph pairs?"},{"title":"Learning Playfair cipher mechanics","prompt":"Use the keyword 'KEYWORD' to set up a Playfair cipher and encode 'HELLO WORLD' so I can see the 5x5 square and how the letters get paired into digraphs."}],"resultDescription":"Returns the encoded or decoded output text, the 5x5 Playfair key square (rows of letters with I/J merged), the input digraph pairs, the grouped output in digraph format, the keyword used, the mode applied, and any summary or disclaimer notes.","failureModes":["Missing 'text' or 'key' query parameters returns an error","Text exceeding 1000 characters may be rejected or truncated","Non-alphabetic characters may be handled or stripped without warning","Invalid mode value (not 'encode' or 'decode') may default to encode or return an error","Keyword with repeated letters is handled but unusual keywords may produce unexpected squares"],"whenToPreferThis":"Choose this endpoint when you need to apply the classic Playfair digraph substitution cipher specifically — especially when visibility into the 5x5 key square and the digraph pairing steps is important for educational, puzzle, or verification purposes. Prefer it over simpler Caesar or Vigenere endpoints when the user specifically asks for Playfair.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T12:35:24.795Z","isFirstParty":false,"canonicalSlug":"playfair-cipher-encoder-decoder-4a7ec375"}