{"uid":"cap_xa9z5NjRHFQaPNUvAuksF","slug":"fastapi-online-code-explainer-648482f6","name":"fastapi.online Code Explainer","description":"Chat, embeddings, OCR, speech-to-text, image editing, image understanding (captioning/Q&amp;A), text-to-speech, translation, writing tools, classification tools, developer tools, local utilities, format/checksum validators, encoding &amp; crypto utilities, date/time calculators, geo/coordinate math, math &amp; 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/code-explain","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"code":{"type":"string","maxLength":20000,"minLength":1},"language":{"type":"string","maxLength":40}}},"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_yHO4H3AydO1I5gHwCDw0W","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":"Explains a given code snippet in plain language, identifying what it does and how it works","exampleAgentPrompt":"Can you explain what this Python function does in plain English? Here's the code: `def fib(n): return n if n <= 1 else fib(n-1) + fib(n-2)`","exampleUseCases":[{"title":"Onboarding to unfamiliar codebase","prompt":"I just inherited this legacy JavaScript module and have no idea what it does — can you explain it to me line by line? Here's the code: `function throttle(fn, delay) { let last = 0; return function(...args) { const now = Date.now(); if (now - last >= delay) { last = now; fn(...args); } }; }`"},{"title":"Code review assistant for non-technical stakeholders","prompt":"Our developer sent me this SQL query and I need to understand what data it's pulling before I approve it — can you explain what it does? `SELECT u.name, COUNT(o.id) AS order_count FROM users u LEFT JOIN orders o ON u.id = o.user_id GROUP BY u.id HAVING order_count > 5;`"},{"title":"Learning aid for programming students","prompt":"I'm learning Rust and I don't understand what this ownership example is doing — can you walk me through it in plain English? `fn main() { let s1 = String::from(\"hello\"); let s2 = s1; println!(\"{}\", s2); }`"}],"resultDescription":"A plain-language explanation of the submitted code snippet, describing what the code does, how it works, and the logic behind it — suitable for developers seeking clarity or non-technical stakeholders needing a summary.","failureModes":["Empty or missing code field returns a validation error","Code exceeding 20,000 characters is rejected","Ambiguous or obfuscated code may produce inaccurate or vague explanations","Unsupported or extremely niche language may yield generic output","Payment failure via x402 protocol results in 402 response with no explanation returned"],"whenToPreferThis":"Choose this endpoint when you need a quick, pay-per-call code explanation without API key signup overhead. It is well-suited for lightweight developer tooling integrations, one-off code comprehension tasks, or agentic workflows where understanding arbitrary code snippets is a transient step. Prefer it over heavier LLM API calls when you want a dedicated, pre-scoped code-explanation endpoint billed at a fixed micro-rate.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:10:29.502Z","isFirstParty":false}