# x402engine Perplexity Search-Augmented LLM

> x402engine Perplexity Search-Augmented LLM is a paid API for AI agents from x402engine.app, paid per call via x402, $0.06/call, status unknown (last checked 2026-09-13).

Answers questions using a search-augmented LLM (Perplexity) that grounds responses in real-time web search with citations

## Facts

- Endpoint: POST https://x402engine.app/api/llm/perplexity
- Price: $0.06/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402engine-perplexity-search-augmented-llm-ae6ce977
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GdjE_EheNtV8TDZTvJYx9

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 x402engine-perplexity-search-augmented-llm-ae6ce977 -d '<json body>'
```

Example prompt: Search the web and give me an up-to-date, cited answer to: what are the latest developments in nuclear fusion energy as of 2025?

## When to prefer this

Choose this endpoint when you need answers grounded in real-time web information rather than static training data — especially for recent events, current prices, breaking news, or any topic where freshness and citations matter. Prefer this over standard LLM endpoints when source verification is required, or when the user's question cannot be reliably answered from training knowledge alone. At $0.06 per call it is priced for agent use cases that require live search quality.

## Known failure modes

- Empty or malformed messages array causes validation error
- Missing required 'role' or 'content' fields in a message object returns 400
- Query on a topic with no live web results may return a less grounded answer
- max_tokens set too low may result in truncated responses
- Network or upstream Perplexity API outage causes 5xx errors
- Payment failure (insufficient USDC balance) blocks the request via x402 protocol

## How this service works

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

## Output

A natural-language answer generated by Perplexity's search-augmented LLM, grounded in real-time web search results and including citations or references to source URLs. The response follows the conversation format provided in the input messages array.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-perplexity-search-augmented-llm-ae6ce977/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402engine.app](https://www.zero.xyz/host/x402engine.app/llms.txt)