# Causal Web Search

> Causal Web Search is a paid API for AI agents from stripe-agent-payment-mvp.vercel.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-11).

Performs a normalized web search and returns structured results suitable for agent consumption, paid per query via x402.

## Facts

- Endpoint: POST https://stripe-agent-payment-mvp.vercel.app/api/x402/search?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/causal-web-search-3752b589
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VmsxQPzZqwV7PkpUax0ZJ

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 causal-web-search-3752b589 -d '<json body>'
```

Example prompt: Search the web for the top 5 results about 'best open-source LLM frameworks in 2025' and give me the titles and summaries.

## When to prefer this

Use this endpoint when an AI agent needs live, normalized web search results in a structured format, especially within x402 micropayment-enabled pipelines where per-query billing is acceptable. Prefer this over scraping or browser automation when you need clean, pre-normalized result objects without HTML parsing overhead.

## Known failure modes

- Query exceeds 240 character limit — request rejected with validation error
- Count outside 1-10 range — request rejected
- Payment failure via x402 protocol — search not performed
- Query string is empty or missing — validation error
- Upstream search provider unavailable — service error returned

## How this service works

Normalized web search results for agents.

## Output

Returns a normalized list of web search results (up to 10), each containing a title, URL, and snippet/description, structured for direct agent consumption.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "count": {
   "type": "integer",
   "maximum": 10,
   "minimum": 1
  },
  "query": {
   "type": "string",
   "maxLength": 240,
   "minLength": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/causal-web-search-3752b589/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stripe-agent-payment-mvp.vercel.app](https://www.zero.xyz/host/stripe-agent-payment-mvp.vercel.app/llms.txt)