{"uid":"cap_g83v1Iry2DIO9uI-6iRb6","slug":"fastapi-online-zero-shot-text-classifier-5bf09665","name":"fastapi.online Zero-Shot Text Classifier","description":"Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding & crypto utilities, date/time calculators, geo/coordinate math, math & finance calculators, novelty tools, and business/social writing generators — 179 endpoints in all, across multiple specialized self-hosted models. Pay per call with crypto — no signup — or get an API key.","url":"https://api.fastapi.online/zero-shot-classify","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"text":{"type":"string","maxLength":8000,"minLength":1},"labels":{"type":"array","items":{"type":"string"},"maxItems":20,"minItems":2}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_s-gDpwN_i7kjmUJ_tFzmg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Classifies a piece of text into one of several user-defined labels without any prior training, using a self-hosted zero-shot classification model.","exampleAgentPrompt":"Can you classify the following customer review into one of these categories — 'shipping issue', 'product defect', 'billing problem', or 'general praise' — and tell me which fits best: 'My order arrived three weeks late and the packaging was completely crushed.'","exampleUseCases":[{"title":"Support ticket routing by topic","prompt":"I have a support message that says 'I was charged twice for my subscription last month' — can you classify it as one of: 'billing', 'technical issue', 'account access', or 'feature request'?"},{"title":"News article topic detection","prompt":"Classify this headline into one of these topics — 'politics', 'sports', 'technology', 'entertainment', or 'health': 'Scientists develop new mRNA vaccine effective against multiple flu strains.'"},{"title":"Customer sentiment classification","prompt":"Tell me whether this product review is 'positive', 'neutral', or 'negative': 'The battery life is decent but the screen dims way too fast and the buttons feel cheap.'"}],"resultDescription":"Returns a ranked list of the candidate labels with a confidence score for each, indicating how well each label matches the input text. The highest-scoring label represents the predicted class.","failureModes":["Fewer than 2 labels provided — request rejected","More than 20 labels provided — request rejected","Text exceeds 8000 characters — request rejected","Empty or missing text field — validation error","Payment not included or insufficient — 402 Payment Required","Model may assign low confidence to all labels if text is ambiguous or unrelated to all candidates"],"whenToPreferThis":"Choose this endpoint when you need to categorize text into custom, domain-specific labels without having trained a classifier — especially useful for ad hoc routing, triage, or analysis tasks where labels vary per request. Prefer this over fine-tuned classifiers when flexibility matters more than peak accuracy, and over general LLM prompting when you want structured confidence scores across multiple candidate labels at low per-call cost ($0.001 USDC).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:58:12.789Z","isFirstParty":false}