# fold · x402 — Grok-4 Market Intelligence (x402)

> fold · x402 — Grok-4 Market Intelligence (x402) is a paid API for AI agents from x402.fold.computer, paid per call via x402, $2/call, status down (last checked 2026-09-15).

Provides machine-readable onchain market intelligence via the Grok-4 LLM, billed per-call over the x402 micropayment protocol at $2 USDC.

## Facts

- Endpoint: POST https://x402.fold.computer/llm/grok-4-3
- Price: $2/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fold-x402-grok-4-market-intelligence-x402-d5c8184b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_O0M5fA8LXCDbDL0m-YTAL

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 fold-x402-grok-4-market-intelligence-x402-d5c8184b -d '<json body>'
```

Example prompt: Ask fold's Grok-4 endpoint what the current sentiment is around Ethereum L2 fee markets and whether now is a good time to bridge assets — give me a detailed analysis, up to 512 tokens.

## When to prefer this

Choose this endpoint when your agent needs Grok-4-quality reasoning specifically about onchain and crypto market topics and you want pay-per-call billing in USDC without managing API keys or subscriptions. Prefer it over generic OpenAI or Anthropic endpoints when the task is onchain market intelligence and the agent runtime already supports x402 payment headers.

## Known failure modes

- Payment failure: insufficient USDC balance or x402 payment header missing/malformed — endpoint returns 402 Payment Required
- Invalid message format: messages array not in OpenAI chat format — returns 400 Bad Request
- Model overload or timeout: Grok-4 backend unavailable — returns 503 or timeout
- Exceeded max_tokens limit: response truncated or error if value is out of range
- Rate limiting: too many concurrent calls — returns 429

## How this service works

Machine-readable market intelligence for onchain agents, served over x402.

## Output

Returns an OpenAI-format chat completion containing Grok-4's response to the messages, along with x402 cost metadata (amount charged, payment confirmed). The data object mirrors the standard OpenAI completion schema so agents can parse it with existing tooling.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "messages"
 ],
 "properties": {
  "messages": {
   "type": "array",
   "description": "OpenAI-format chat messages"
  },
  "max_tokens": {
   "type": "number"
  },
  "temperature": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "status",
  "data"
 ],
 "properties": {
  "data": {
   "type": "object",
   "description": "OpenAI-format completion + x402 cost info"
  },
  "status": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fold-x402-grok-4-market-intelligence-x402-d5c8184b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.fold.computer](https://www.zero.xyz/host/x402.fold.computer/llms.txt)