# Delx Keyword Density

> Delx Keyword Density is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Measures the density of specified keywords or phrases within caller-supplied text, returning machine-readable JSON results.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/keyword-density
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-keyword-density-a91a7308
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_g3vDRbdyAq1wL1Fsx_w7I

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 delx-keyword-density-a91a7308 -d '<json body>'
```

Example prompt: Can you measure the keyword density of 'machine learning' and 'neural network' in this article text I have: 'Machine learning models have transformed how neural networks are trained. Neural network architectures vary widely...'?

## When to prefer this

Choose this endpoint when you already hold the text and need a fast, deterministic, stateless measurement of keyword frequency and density. It is ideal for SEO audits, content quality checks, spam analysis, or any NLP pipeline step that requires knowing how prominently specific terms appear in a document. It does not fetch URLs or search the web — the caller must supply the text directly.

## Known failure modes

- Empty or missing text field returns an error or zero results
- Empty keywords array returns no density metrics
- Extremely short text may produce unreliable or zero density values
- Very long text inputs may hit payload size limits
- Malformed JSON request body returns a 400-level error

## How this service works

Measure keyword density inside caller-supplied text — call when measuring keyword density in held text. Use on text/URLs the agent already holds—adjacent to high-volume extract demand, never advertised as general web or X search. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, and no claim of live chain tip, web search, or media generation. Results are adviso…

## Output

Returns a deterministic JSON object containing per-keyword density metrics — including occurrence counts, frequency ratios, and density percentages — for each keyword or phrase measured against the supplied text. Results are stateless and advisory.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "UTF-8 text to encode, chunk, index, or analyze (caller-supplied only)."
  },
  "keywords": {
   "type": "array",
   "description": "Keywords or phrases to measure inside the supplied text."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "schema": "delx/util-keyword-density/v1",
  "keywords": [
   {
    "count": 2,
    "keyword": "agent",
    "density_percent": 40
   },
   {
    "count": 1,
    "keyword": "commerce",
    "density_percent": 20
   }
  ],
  "word_count": 5
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-keyword-density-a91a7308/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)