# HydraTrader NLP Keyword Extraction

> HydraTrader NLP Keyword Extraction is a paid API for AI agents from x402.hydratrader.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-01).

Extracts keywords from a given text input using a pay-per-call NLP endpoint via the x402 micropayment protocol

## Facts

- Endpoint: POST https://x402.hydratrader.ai/v1/keywords?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hydratrader-nlp-keyword-extraction-2e8c813d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4n39Vw9zyOjMV530jGBpQ

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 hydratrader-nlp-keyword-extraction-2e8c813d -d '<json body>'
```

Example prompt: Pull out the most important keywords from this article text: 'Artificial intelligence is transforming healthcare by enabling faster diagnosis, personalized treatment plans, and predictive analytics for hospital resource management.'

## When to prefer this

Choose this endpoint when you need lightweight, pay-per-call keyword extraction without setting up an API key or subscription — ideal for agent workflows that process text intermittently and want to pay only for actual usage via USDC micropayments. It is particularly suited for agents already operating in the x402 payment ecosystem.

## Known failure modes

- HTTP 402 returned if payment is not attached or USDC balance is insufficient
- Input text exceeding 8000 characters will be rejected
- Malformed JSON body or missing 'input' field returns a 400 error
- Network timeouts if the underlying NLP model is slow to respond
- Empty or very short input text may yield sparse or no keyword results

## How this service works

Extract keywords: Verb-path alias of POST /v1/cheap-errand ($0.01 USDC). Same handler + payment terms; path defaults task=extract_keywords when body.task omitted. Cheap agent glue for buyer-supplied text. Base via x402. No API key.

## Output

Returns the extracted keywords or key phrases from the submitted text, surfacing the most topically significant terms present in the input.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "task": {
   "enum": [
    "summarize",
    "rewrite",
    "classify",
    "extract_keywords",
    "sentiment",
    "translate"
   ],
   "type": "string"
  },
  "input": {
   "type": "string",
   "maxLength": 8000
  },
  "options": {
   "type": "object"
  },
  "client_ref": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hydratrader-nlp-keyword-extraction-2e8c813d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.hydratrader.ai](https://www.zero.xyz/host/x402.hydratrader.ai/llms.txt)