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fastapi.online Code Explainer
x402
fastapi.online Code Explainer is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Explains a given code snippet in plain language, identifying what it does and how it works
Price / call$0.001
Success—
StatusUnknown
How this service works
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.
Output
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.
Example use cases
Onboarding to unfamiliar codebase
“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); } }; }`”
Code review assistant for non-technical stakeholders
“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;`”
Learning aid for programming students
“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); }`”
Technical details
Endpoint
POSThttps://api.fastapi.online/code-explainWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| code | string | |
| language | string |
Tags
x402
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