# Topic Scorer – Taxonomy Rank Gate

> Topic Scorer – Taxonomy Rank Gate is a paid API for AI agents from topic-scorer.pixelcove.co, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-13).

Checks whether a piece of text ranks within the top N categories of a given ad or content taxonomy, returning pass/fail, rank, gap to #1, top 5 categories, and unused phrases to improve topical coverage.

## Facts

- Endpoint: POST https://topic-scorer.pixelcove.co/v1/gate
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/topic-scorer-taxonomy-rank-gate-c563cf7c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Lnt6m9y2kVsUc2J5PpgK8

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-rank-gate-c563cf7c -d '<json body>'
```

Example prompt: Check if this article draft passes a top-3 rank check for the IAB content category 'Technology & Computing > Artificial Intelligence' using the iab_content taxonomy, and tell me which phrases I'm missing — here's the text: [article text].

## When to prefer this

Use this endpoint when you need a deterministic pass/fail gate on whether content is topically aligned with a specific category in a standardized ad or content taxonomy (IAB, Google Ads, Google Merchant, LinkedIn Industries). It is particularly valuable in automated content pipelines where you need a hard threshold check before publishing, submitting ads, or approving content. Prefer this over general-purpose LLM classification when you need reproducible, taxonomy-anchored results with improvement guidance (unused phrases) and ranking context (top 5, gap to #1).

## Known failure modes

- Category not found or ambiguous path substring — use topic_scorer_find to look up a valid category id
- Text too short (under 1 character) or too long (over 32,768 characters)
- Invalid taxonomy enum value supplied
- min_rank out of bounds (must be 1–50)
- Payment failure or insufficient funds — $0.05 USDC required per call
- Service unavailable or timeout on large full-text scoring requests

## How this service works

Pass/fail check: does the text rank within the top `min_rank` categories of its target taxonomy? Returns `pass`, the target's rank and gap to #1, the taxonomy's top five, and the unused phrases to work in. Use it as a content-pipeline gate. Paid, $0.05/call; read-only and safe to retry.

## Output

Returns a pass/fail verdict indicating whether the text ranks within the specified top-N threshold for the target category, the target category's actual rank, its scoring gap to the #1 ranked category, the taxonomy's top 5 scoring categories for the text, and a bank of unused topically-relevant phrases that could be incorporated to improve ranking.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "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)."
  },
  "min_rank": {
   "type": "integer",
   "default": 3,
   "maximum": 50,
   "minimum": 1,
   "description": "Highest passing rank."
  },
  "taxonomy": {
   "enum": [
    "google_ads_topics",
    "google_merchant",
    "iab_content",
    "iab_audience",
    "iab_ad_product",
    "linkedin_industries"
   ],
   "type": "string",
   "description": "Taxonomy of the target category."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/topic-scorer-taxonomy-rank-gate-c563cf7c/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)