{"uid":"cap__CEuDr7Dn5XgLS76MkoGj","slug":"character-4-gram-counter-247821d5","name":"Character 4-gram Counter","description":"Call when an agent needs counts of char 4-grams. No network and no LLM. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/ngram-char-4 first.","url":"https://agentshelf.syntexa.ch/v1/ngram-char-4?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"text":{"type":"string","examples":["ab ab"],"maxLength":100000,"minLength":1,"description":"Input for this SKU. The route description says whether it is plain text, a URL, base64 bytes, or an already-encoded token."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.008","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":"$0.008/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.008","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.008","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Qj54Gb0UJdp1tyDc14q01","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.008","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Counts occurrences of every character-level 4-gram (sliding window of 4 consecutive characters) in a given text string, with no network calls or LLM involvement.","exampleAgentPrompt":"Count the character 4-grams in this text: 'The quick brown fox jumps over the lazy dog' — give me the frequency of every 4-character sliding window sequence.","exampleUseCases":[{"title":"NLP feature extraction for classifier","prompt":"I need the character 4-gram counts for this product review: 'Absolutely loved the packaging and the scent was divine, will reorder soon' — I want to use these as features for a text classifier."},{"title":"Language detection preprocessing","prompt":"Can you compute all character 4-gram frequencies for this sentence: 'Bonjour, comment allez-vous aujourd'hui?' — I'm building a language detection model and need the char-level ngram distribution."},{"title":"Duplicate text fingerprinting","prompt":"Get me the character 4-gram counts for 'agentshelf syntexa provides deterministic text analysis without any network calls' so I can use them to build a text fingerprint for near-duplicate detection."}],"resultDescription":"A map of every distinct 4-character substring (sliding window, step 1) found in the input text to its integer occurrence count, computed deterministically with no external calls.","failureModes":["Empty or missing 'text' field returns a validation error","Text exceeding 100,000 characters is rejected","Payment of exactly $0.008 USDC required; insufficient or missing payment results in 402 response","Malformed JSON body returns 400 error"],"whenToPreferThis":"Use this endpoint when you need exact, deterministic character 4-gram counts from a text string with no LLM involvement and no network dependencies. It is preferable when you need reproducible ngram statistics for NLP feature engineering, language modeling, or text fingerprinting. Try the unpaid sandbox at POST /v1/sandbox/ngram-char-4 first to validate your integration before paying.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T06:50:25.064Z","isFirstParty":false,"canonicalSlug":"character-4-gram-counter-247821d5"}