# fastapi.online Keyword Extraction

> fastapi.online Keyword Extraction is a paid API for AI agents from api.fastapi.online, paid per call via x402, $0.001/call, status down (last checked 2026-09-15).

Extracts the most relevant keywords from a given text, optionally limiting the number returned

## Facts

- Endpoint: POST https://api.fastapi.online/keywords
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastapi-online-keyword-extraction-1500505b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uf70FHtWbaShK1wzhUCgh

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fastapi-online-keyword-extraction-1500505b -d '<json body>'
```

Example prompt: Extract the top 5 keywords from this article text: 'Artificial intelligence is transforming the way businesses operate, with machine learning models now powering customer service, logistics, and product recommendations at scale.'

## When to prefer this

Choose this endpoint when you need lightweight, pay-per-call keyword extraction without account setup, and your workflow already uses x402 crypto micropayments. It is ideal for agents processing variable volumes of documents where per-call pricing is more cost-effective than a subscription. Prefer it over heavy NLP pipelines when you only need keywords, not full entity recognition or deep semantic parsing.

## Known failure modes

- Missing required 'text' field returns a validation error
- Empty string input may return an empty keywords array
- Very short text may yield fewer keywords than max_keywords requested
- max_keywords set to 0 or negative values may cause unexpected behavior
- Rate limiting or payment failure (402) if USDC balance is insufficient

## How this service works

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.

## Output

Returns a JSON object containing a 'keywords' array of the most relevant terms or phrases extracted from the input text, ordered by relevance or frequency depending on the model's logic.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "maxLength": 8000,
   "minLength": 1
  },
  "max_keywords": {
   "type": "integer",
   "maximum": 20,
   "minimum": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastapi-online-keyword-extraction-1500505b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fastapi.online](https://www.zero.xyz/host/api.fastapi.online/llms.txt)