---
title: "Cross-model PQS comparison, Claude vs GPT-4o ($1.25 USDC)"
method: POST
path: "/api/score/compare"
tags: ["compare", "paid", "evm"]
---

# Cross-model PQS comparison, Claude vs GPT-4o ($1.25 USDC)

`POST /api/score/compare`

## Request

- Base URL: `https://promptqualityscore.com`
- URL: `https://promptqualityscore.com/api/score/compare`
- Auth: one of:
  - API key in header `X-PAYMENT`
  - API key in header `Authorization`

Cross-model scoring: Claude Sonnet 4 vs GPT-4o, judged by a third model

## Request body

- object
  - `prompt` string, required: Prompt to score
  - `vertical` 'software' | 'content' | 'business' | 'education' | 'science' | 'crypto' | 'general' | 'research'

## Response `200`

Scoring result

- object
  - `pqs_version` '2.0', required
  - `original_prompt` string
  - `optimized_prompt` string
  - `vertical` string
  - `results` object, required
    - `claude` object
      - `model` string
      - `output` string
      - `scores` object
        - `completeness` integer
        - `relevancy` integer
        - `reasoning_depth` integer
        - `faithfulness` integer
        - `total` integer
    - `gpt4o` object
      - `model` string
      - `output` string
      - `scores` object
        - `completeness` integer
        - `relevancy` integer
        - `reasoning_depth` integer
        - `faithfulness` integer
        - `total` integer
  - `winner` 'claude' | 'gpt4o', required
  - `verdict` string, required
  - `powered_by` string

## Other responses

- `400`: Invalid request body
- `401`: Invalid or missing bearer API key (when using bearer auth)
- `402`: Payment Required - x402 challenge when no bearer API key present. See x-payment-info.

---

[API](https://skmtc.dev/promptqualityscore/apis/pqs-prompt-quality-score.md) · [All operations](https://skmtc.dev/promptqualityscore/apis/pqs-prompt-quality-score/llms.txt) · [OpenAPI document](https://skmtc.dev/promptqualityscore/apis/pqs-prompt-quality-score/revisions/7f3f43a1c864?raw)