# WhatChUNeed LLM Chat

> WhatChUNeed LLM Chat is a paid API for AI agents from whatchuneed.vercel.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Send a prompt to a hosted LLM and receive a text response, with optional model override and system prompt, via pay-per-call API.

## Facts

- Endpoint: POST https://whatchuneed.vercel.app/api/llm/chat
- 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/whatchuneed-llm-chat-54d272fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DMaxAXHEULCqX7uNXfnvL

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 whatchuneed-llm-chat-54d272fa -d '<json body>'
```

Example prompt: Ask the WhatChUNeed LLM chat endpoint this question as the user: 'What are the top three causes of the French Revolution?' — use a system prompt that says 'You are a concise historian' and limit the response to 300 tokens.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call LLM text generation capability without committing to a monthly subscription, especially if your agent operates in a crypto-native or x402-compatible payment environment. It is well-suited for sporadic or bursty LLM usage where per-call USDC micropayments are more economical than a flat-rate plan.

## Known failure modes

- Payment failure or insufficient USDC balance causes 402 error before the request is processed
- Missing required 'prompt' field returns a 400 validation error
- Invalid or unsupported model identifier in the 'model' override field may cause a 422 or fallback to default model
- max_tokens value too large may be capped or rejected depending on underlying model limits
- Prompt triggering content policy violations may return a filtered or empty response

## How this service works

320+ pay-per-call API endpoints across accommodation, LLM, code execution, crypto, medical, finance, and more. One API, one payment. Powered by x402 protocol.

## Output

A JSON object containing the name of the model that processed the request and the generated text response to the provided prompt.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "prompt"
 ],
 "properties": {
  "model": {
   "type": "string",
   "description": "Model override"
  },
  "prompt": {
   "type": "string",
   "description": "The user message"
  },
  "system": {
   "type": "string",
   "description": "System prompt"
  },
  "max_tokens": {
   "type": "integer"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string"
  },
  "response": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/whatchuneed-llm-chat-54d272fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from whatchuneed.vercel.app](https://www.zero.xyz/host/whatchuneed.vercel.app/llms.txt)