# PQS: Prompt Quality Score – Cross-Model Compare (Solana x402)

> PQS: Prompt Quality Score – Cross-Model Compare (Solana x402) is a paid API for AI agents from api.relai.fi, paid per call via x402, $1.25/call, status unknown (last checked 2026-09-14).

Scores a prompt for quality across multiple AI models and verticals, returning a comparative quality assessment

## Facts

- Endpoint: GET https://api.relai.fi/relay/1779373065272/api/score/compare/sol
- Price: $1.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pqs-prompt-quality-score-cross-model-compare-solana-x402-6b52ef99
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DHFQTpJ9FYjMuZ5gG-8Is

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-cross-model-compare-solana-x402-6b52ef99
```

Example prompt: Can you score this prompt for quality using PQS across models — 'Write a Python function that parses JSON and handles errors gracefully' — and use the software vertical?

## When to prefer this

Use this endpoint when you need an objective, cross-model quality score for a prompt before deploying it, especially when optimizing prompts for specific verticals like software, content, research, or crypto. Prefer this over manual review or single-model evaluation when you want a comparative, multi-model perspective on prompt effectiveness.

## Known failure modes

- Empty or missing prompt returns 400 validation error
- Prompt exceeding 10,000 characters returns length error
- Invalid vertical enum value returns schema validation error
- Payment not provided or insufficient (x402 payment required) returns 402
- Service unavailable returns 503
- Malformed request returns 400

## How this service works

Cross-model scoring (Solana x402)

## Output

Returns a cross-model prompt quality score and comparative analysis for the given prompt, indicating how effective and well-formed the prompt is across different AI models within the specified vertical.

## 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"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pqs-prompt-quality-score-cross-model-compare-solana-x402-6b52ef99/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)