# Perplexity Search-Augmented LLM via x402 Gateway

> Perplexity Search-Augmented LLM via x402 Gateway is a paid API for AI agents from x402-gateway-production.up.railway.app, paid per call via x402, $0.060000/call, status unknown (last checked 2026-09-15, last successful call 2026-05-01).

Answers questions using an LLM grounded in real-time web search, returning responses with citations to live sources

## Facts

- Endpoint: POST https://x402-gateway-production.up.railway.app/api/llm/perplexity
- Price: $0.060000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Last successful call: 2026-05-01
- Success rate: 55% of calls made through Zero
- Activations on Zero: 11
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-gateway-production-up-railway-app-b3727b68
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MEG8ME31wXI_wbS0aPdO1

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 x402-gateway-production-up-railway-app-b3727b68 -d '<json body>'
```

Example prompt: What are the latest developments in the EU AI Act as of this week? I need an answer with citations to real sources, not just your training data.

## When to prefer this

Choose this endpoint when the user's question requires up-to-date, real-world information that a static LLM would not reliably know — such as recent news, current prices, live events, or recent research. It is superior to plain LLM endpoints when source citations are important for trust or verification. Prefer this over raw search APIs when you need a synthesized, readable answer rather than a list of raw URLs.

## Known failure modes

- Query times out if web search takes too long — returns error or partial response
- No relevant web results found for highly obscure or very niche queries
- Payment not included or invalid — returns 402 Payment Required
- Perplexity upstream outage — returns 503 or gateway error
- Rate limiting if too many requests sent in quick succession

## How this service works

Search-augmented LLM — answers grounded in real-time web search with citations

## Output

A natural language answer to the query, grounded in real-time web search results, along with citations including source titles and URLs that back up the response. The answer reflects current information retrieved at query time rather than static training data.

## Example request

```json
{
 "messages": [
  {
   "role": "user",
   "content": "What are the latest developments in artificial intelligence in 2024?"
  }
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-gateway-production-up-railway-app-b3727b68/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production.up.railway.app](https://www.zero.xyz/host/x402-gateway-production.up.railway.app/llms.txt)