# PQS /api/score — 8-Dimension Prompt Quality Scorer

> PQS /api/score — 8-Dimension Prompt Quality Scorer is a paid API for AI agents from promptqualityscore.com, paid per call via x402, $0.025/call, status unknown (last checked 2026-10-11).

Scores a prompt across 8 dimensions (clarity, context, examples, constraints, specificity, chain-of-thought structure, output format, role definition) with a grade, percentile, and top 3 actionable fixes

## Facts

- Endpoint: GET https://promptqualityscore.com/api/score?utm_source=zero.xyz
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/promptqualityscore-com-fc9e687f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zm1r2GKWiq655l7BD3Uv9

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 promptqualityscore-com-fc9e687f
```

Example prompt: Can you score this prompt for a software task and tell me the grade, dimension breakdown, and top 3 things to fix? Prompt: 'You are a senior engineer. Review the following code and suggest improvements focusing on performance.'

## When to prefer this

Use this endpoint when you need a detailed, multi-dimensional quality breakdown of a prompt with dimension-level sub-scores and prioritized fixes — not just a pass/fail or single composite score. Ideal for prompt debugging workflows, prompt optimization pipelines, or pre-flight filtering before expensive LLM calls where you want to understand *why* a prompt is weak and exactly what to fix.

## Known failure modes

- Missing required 'prompt' field — returns validation error
- Prompt too short or empty — may return low scores or error
- Invalid vertical value — falls back to 'general' or returns validation error
- Network timeout on large prompts
- Payment failure (x402) — endpoint returns 402 if USDC payment not attached

## How this service works

A Quality Gate For Prompts. Before they break production. Score any AI prompt against 8 dimensions, see what's weak, and get the fixed version in seconds.

## Output

Returns a structured object with: a total score (8–80), letter grade (A–F), percentile rank, individual scores for all 8 dimensions (clarity, context, examples, constraints, specificity, cot_structure, output_format, role_definition), an upgraded prompt string, and exactly 3 specific fix recommendations

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "prompt": {
   "type": "string",
   "maxLength": 10000,
   "minLength": 1,
   "description": "Prompt to score"
  },
  "vertical": {
   "enum": [
    "software",
    "content",
    "business",
    "education",
    "science",
    "crypto",
    "general",
    "research"
   ],
   "type": "string",
   "default": "general",
   "description": "Domain: software/content/business/education/science/crypto/general/research"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "score": {
   "grade": "C",
   "total": 46,
   "out_of": 80,
   "dimensions": {
    "total": 46,
    "clarity": 7,
    "context": 6,
    "examples": 4,
    "constraints": 5,
    "specificity": 6,
    "cot_structure": 6,
    "output_format": 7,
    "role_definition": 5
   },
   "percentile": 58
  },
  "prompt": "Explain PQS scoring in one sentence to an AI agent operator.",
  "upgrade": "For optimized prompt call /api/score/full at $0.125 USDC",
  "vertical": "general",
  "top_fixes": [
   "Specify the exact output format you want (bullets, JSON, prose).",
   "Name the target reader or persona explicitly.",
   "Add one concrete example of the ideal response."
  ],
  "powered_by": "PQS - promptqualityscore.com",
  "pqs_version": "2.0"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/promptqualityscore-com-fc9e687f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from promptqualityscore.com](https://www.zero.xyz/host/promptqualityscore.com/llms.txt)