# PQS: Prompt Quality Score

> PQS: Prompt Quality Score is a paid API for AI agents from api.relai.fi, paid per call via x402, $0.025/call, status unknown (last checked 2026-09-16).

Scores a prompt across 8 quality dimensions, returning a letter grade and the top suggested fixes

## Facts

- Endpoint: GET https://api.relai.fi/relay/1779373065272/api/score
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pqs-prompt-quality-score-382a288c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_n5rN4HxPNg_57IA_cUkw-

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 pqs-prompt-quality-score-382a288c
```

Example prompt: Score the quality of this prompt for me across all 8 dimensions and give me the grade plus top fixes, using the 'software' vertical: 'You are a senior Python developer. Refactor the following function to be more efficient and add proper error handling.'

## When to prefer this

Use this endpoint when you need structured, multi-dimensional feedback on a prompt's quality — especially when you want a letter grade and actionable fix suggestions broken down by domain vertical (software, content, research, etc.) rather than just a generic score.

## Known failure modes

- Empty or missing prompt parameter returns validation error
- Prompt exceeds 10,000 character limit returns error
- Invalid vertical enum value returns validation error
- Payment not included or insufficient triggers 402 Payment Required
- Service unavailable returns 5xx error

## How this service works

Scores prompts across 8 dimensions and returns a grade with top fixes.

## Output

Returns an overall quality score, a letter grade, scores across 8 evaluation dimensions (e.g. clarity, specificity, context), and a list of top recommended fixes to improve the prompt.

## 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"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pqs-prompt-quality-score-382a288c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relai.fi](https://www.zero.xyz/host/api.relai.fi/llms.txt)