# SCOPE Research API – Compare Endpoint

> SCOPE Research API – Compare Endpoint is a paid API for AI agents from x402-agent.scope-research-api.workers.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Compares two topics, products, or entities side-by-side using source-backed public web research, optionally evaluated against specific criteria.

## Facts

- Endpoint: POST https://x402-agent.scope-research-api.workers.dev/compare
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/scope-research-api-compare-endpoint-4e3653bb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_whayvKzm0efQ9ET0bLzp2

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 scope-research-api-compare-endpoint-4e3653bb -d '<json body>'
```

Example prompt: Can you do a source-backed web research comparison of React vs Vue — looking at performance, ecosystem, and learning curve?

## When to prefer this

Choose this endpoint when you need a neutral, source-backed head-to-head comparison of two specific topics, products, technologies, or entities — especially when accuracy and citation quality matter. It is preferable over general search when structured comparative output is needed and over LLM-only answers when you need grounding in real public web sources. Best for research-heavy agent workflows that require defensible, sourced analysis rather than opinion.

## Known failure modes

- Missing required 'left' or 'right' fields returns a 400 validation error
- Payment not included or insufficient triggers a 402 Payment Required response
- Ambiguous or very obscure entity names may return low-quality or inconclusive comparisons
- Rate limiting or upstream web research failures may result in 5xx errors
- Criteria array with unsupported or vague items may be ignored or partially addressed

## How this service works

Source-backed public web research API for AI agents using x402 payments.

## Output

A structured, source-backed comparative analysis of the two input entities. The response includes research findings for each side, evaluated against any provided criteria, with citations or references to public web sources supporting the conclusions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "left",
  "right"
 ],
 "properties": {
  "left": {
   "type": "string"
  },
  "right": {
   "type": "string"
  },
  "criteria": {
   "type": "array"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/scope-research-api-compare-endpoint-4e3653bb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-agent.scope-research-api.workers.dev](https://www.zero.xyz/host/x402-agent.scope-research-api.workers.dev/llms.txt)