# Grok 4.5 High Chat Completions via x402

> Grok 4.5 High Chat Completions via x402 is a paid API for AI agents from x402donghang.duckdns.org, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Provides OpenAI-compatible chat completions using the Grok 4.5 High model, billed per-call at $0.01 USDC via the x402 payment protocol.

## Facts

- Endpoint: POST https://x402donghang.duckdns.org/x402/v1/models/grok-4.5-high/chat/completions
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/grok-4-5-high-chat-completions-via-x402-1578fb27
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1i1eMlqboHetu1RAUIKxg

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 grok-4-5-high-chat-completions-via-x402-1578fb27 -d '<json body>'
```

Example prompt: Ask Grok 4.5 High this question using the pay-per-call API: 'What are the top three factors driving ETH price action right now?' — up to 500 tokens, no streaming.

## When to prefer this

Choose this endpoint when you need access to Grok 4.5 High's reasoning capabilities without a monthly xAI subscription, especially in agentic pipelines that already handle x402 micropayments. It is ideal for low-frequency or burst usage where per-call billing ($0.01 USDC) is cheaper than a subscription, and when you need an OpenAI-compatible interface so you can swap it in with minimal code changes.

## Known failure modes

- Payment failure or insufficient USDC balance returns 402 Payment Required
- Invalid model name other than 'grok-4.5-high' may cause a 400 or model-not-found error
- Malformed messages array (missing role or content) returns validation error
- max_tokens set too high may be capped or cause timeout
- Service unavailability on the duckdns-hosted server returns 503 or timeout

## How this service works

Start with DeepSeek V4 Flash at $0.003/call. Six OpenAI-compatible models plus crypto radar/brief/summarize. Free samples. Pay USDC via x402 — no signup.

## Output

Returns an OpenAI-compatible chat completion JSON object containing an id, model name ('grok-4.5-high'), object type ('chat.completion'), and a choices array with the assistant's message content, role, and finish reason (e.g. 'stop').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Use \"grok-4.5-high\""
  },
  "stream": {
   "type": "boolean"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   }
  },
  "max_tokens": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-x402",
  "model": "grok-4.5-high",
  "object": "chat.completion",
  "choices": [
   {
    "index": 0,
    "message": {
     "role": "assistant",
     "content": "Hello!"
    },
    "finish_reason": "stop"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/grok-4-5-high-chat-completions-via-x402-1578fb27/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402donghang.duckdns.org](https://www.zero.xyz/host/x402donghang.duckdns.org/llms.txt)