# topic-scorer: Taxonomy Scoring over MCP by PixelCove

> topic-scorer: Taxonomy Scoring over MCP by PixelCove is a paid API for AI agents from topic-scorer.pixelcove.co, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-11).

Scores a text document against 11,485 public taxonomy categories and returns ranked matches plus missing phrases needed to improve targeting.

## Facts

- Endpoint: POST https://topic-scorer.pixelcove.co/v1/score?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/topic-scorer-taxonomy-scoring-over-mcp-by-pixelcove-468f61fd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TowAK94L_4eMxFocAaUcV

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 topic-scorer-taxonomy-scoring-over-mcp-by-pixelcove-468f61fd -d '<json body>'
```

Example prompt: Score this article against the google_ads_topics taxonomy, targeting the category 'Computers & Electronics > Computer Security > Network Security', and give me the top 10 results plus up to 30 phrases I still need to include: [paste article text here].

## When to prefer this

Choose this endpoint when you need precise, ranked placement of a piece of content within a named public taxonomy (Google Ads Topics, IAB Content, IAB Audience, IAB Ad Product, Google Merchant, or LinkedIn Industries) and want actionable phrase suggestions to improve category relevance. It is ideal for content optimization workflows, ad targeting validation, and programmatic SEO. Prefer it over generic keyword tools when you need structured taxonomy-level scoring with a gap analysis, not just keyword density or raw similarity.

## Known failure modes

- Text exceeds 32,768 character limit — request rejected
- Category string does not uniquely match any taxonomy entry — use topic_scorer_find to resolve
- Taxonomy enum value not recognized — must be one of the six supported values
- Empty or whitespace-only text input — minimum 1 character required
- Payment not completed — x402 payment of $0.05 USDC required per call
- Text too short to produce meaningful embeddings — low-confidence scores returned

## How this service works

An MCP server that scores a page or draft against 11,485 public taxonomy categories, returns its rank per taxonomy, and gives you the phrases it still needs. $0.05 per call.

## Output

Returns a JSON object containing: the number of characters scored, the embedding model used, the target category's rank and relevance score and gap to top, a phrase bank split into used and unused phrases for the target category, and a breakdown of top-ranked categories across the requested taxonomy with their IDs, full paths, ranks, and scores.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "per": {
   "type": "integer",
   "default": 10,
   "maximum": 25,
   "minimum": 1,
   "description": "Rows per taxonomy."
  },
  "full": {
   "type": "boolean",
   "default": false,
   "description": "Score the whole text as the mean of 8,192-char chunks instead of only the first 8,192 chars."
  },
  "text": {
   "type": "string",
   "maxLength": 32768,
   "minLength": 1,
   "description": "The page or draft text to score, as plain text or HTML (tags are stripped). 1 to 32768 characters. URLs are not fetched; send the content."
  },
  "phrases": {
   "type": "integer",
   "default": 30,
   "maximum": 100,
   "minimum": 0,
   "description": "Phrase bank size for the target category (0 skips it)."
  },
  "category": {
   "type": "string",
   "maxLength": 200,
   "minLength": 1,
   "description": "Target category id, full path, or a unique path substring within the taxonomy (use topic_scorer_find to look one up)."
  },
  "taxonomy": {
   "enum": [
    "google_ads_topics",
    "google_merchant",
    "iab_content",
    "iab_audience",
    "iab_ad_product",
    "linkedin_industries"
   ],
   "type": "string",
   "description": "Taxonomy of the target category."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chars": 5120,
  "model": "gemini-embedding-001",
  "target": {
   "id": "344",
   "path": "Computers & Electronics > Computer Security > Network Security",
   "rank": 1,
   "score": 0.842,
   "gap_to_top": 0
  },
  "phrases": {
   "used": [
    "firewall"
   ],
   "unused": [
    "intrusion detection"
   ]
  },
  "taxonomies": {
   "google_ads_topics": {
    "top": [
     {
      "id": "344",
      "path": "...",
      "rank": 1,
      "score": 0.842
     }
    ],
    "count": 2558,
    "label": "Google Ads Topics"
   }
  },
  "scored_chars": 5120
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/topic-scorer-taxonomy-scoring-over-mcp-by-pixelcove-468f61fd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from topic-scorer.pixelcove.co](https://www.zero.xyz/host/topic-scorer.pixelcove.co/llms.txt)