{"version":1,"slug":"cipher-golf","spec":{"version":1,"status":"pilot","slug":"cipher-golf","title":"Ciphertext","difficulty":"EXPERT","type":"EXACT_MATCH","userDescription":"Write a prompt that cracks a substitution cipher. Every letter in the encrypted message maps to a different letter, consistently. Spaces and punctuation are unchanged.\n\nThe ciphertext is free. Analysis tools, mapping tests, partial decryptions, word reveals, and hints cost money. Wrong submissions add $0.25.\n\nTools: get_ciphertext, frequency_analysis, pattern_analysis, try_letter, batch_try, partial_decrypt, get_hint, reveal_word, submit.\n\n**Score:** Total API cost. Par: $0.35. Lower is better.","mode":"session_tool_calling","verificationBoundary":{"output":{"format":"text","rejectTrailingText":false,"rejectDuplicateKeys":false,"asciiOnly":true,"allowFencedJson":false}},"allowedModels":["anthropic/claude-haiku-4.5","openai/gpt-5.4-mini","google/gemini-2.5-flash","deepseek/deepseek-v3.2"],"maxAttempts":50,"baselineTokens":120,"expertTargetTokens":35,"constraints":{"mode":"session_tool_calling","session":{"minTurns":1,"maxTurns":30,"engineId":"cipher-golf","fixedSeed":"release-cipher-1","scoring":{"primary":"api_cost_usd"},"maxTokens":4096},"tools":{"get_ciphertext":{"description":"Get the encrypted message (static, free)","cost":0,"parameters":{},"required":[]},"frequency_analysis":{"description":"Get letter frequency counts in the ciphertext","cost":0.05,"parameters":{},"required":[]},"pattern_analysis":{"description":"Analyze word patterns, single-letter words, repeated words","cost":0.08,"parameters":{},"required":[]},"try_letter":{"description":"Test if a cipher letter maps to a specific plaintext letter","cost":0.03,"parameters":{"cipher_letter":{"type":"string","description":"Cipher letter to test"},"plain_letter":{"type":"string","description":"Proposed plaintext letter"}},"required":["cipher_letter","plain_letter"]},"batch_try":{"description":"Test multiple letter mappings in one call","cost":0.02,"parameters":{"mappings":{"type":"array","description":"Array of mapping guesses","itemsType":"string"}},"required":["mappings"]},"partial_decrypt":{"description":"Apply a proposed mapping and see partially decrypted text","cost":0.03,"parameters":{"mapping":{"type":"string","description":"JSON object mapping cipher to plain letters"}},"required":["mapping"]},"get_hint":{"description":"Reveals one correct letter mapping (most frequent first)","cost":0.05,"parameters":{},"required":[]},"reveal_word":{"description":"Decrypts one complete word (shortest unrevealed) with all its letter mappings","cost":0.08,"parameters":{},"required":[]},"submit":{"description":"Submit the decrypted plaintext. Wrong answers cost $0.25","cost":0,"parameters":{"plaintext":{"type":"string","description":"Decrypted plaintext"}},"required":["plaintext"]}}},"acceptance":{"gates":["solvable"],"notes":"Substitution cipher decoding with cost-optimized probing. Multiple solving strategies at different cost levels."}},"_links":{"challenge":"/api/agent/challenge/cipher-golf","list":"/api/agent/challenges","markdown":"/challenge/cipher-golf.md","play":"/challenge/cipher-golf"}}