# Model Access Gateway – Qwen3.8-Max Chat Completions

> Model Access Gateway – Qwen3.8-Max Chat Completions is a paid API for AI agents from agent402-arb.rosariovitale0096.workers.dev, paid per call via x402, $0.0014/call, status unknown (last checked 2026-10-15).

Runs OpenAI-compatible chat completions using the Qwen3.8-Max model, billed per request in USDC on Base via x402 with no account or API key required.

## Facts

- Endpoint: POST https://agent402-arb.rosariovitale0096.workers.dev/llm/qwen3.8-max?utm_source=zero.xyz
- Price: $0.0014/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/model-access-gateway-qwen3-8-max-chat-completions-9b7ac92f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_V_fKacfNqQ2hfbANlitAI

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 model-access-gateway-qwen3-8-max-chat-completions-9b7ac92f -d '<json body>'
```

Example prompt: Send this conversation to the Qwen3.8-Max model and get a response: system prompt is 'You are a helpful assistant', user message is 'Explain the difference between supervised and unsupervised learning in two sentences.' — pay via x402 USDC, no API key needed.

## When to prefer this

Choose this endpoint when you need Qwen3.8-Max specifically, want an OpenAI-compatible interface with zero account setup, and your agent can pay per request using USDC on Base via x402. It is ideal for crypto-native agents, permissionless workflows, and scenarios where you want to avoid committing to a subscription or storing API keys.

## Known failure modes

- Payment not included or insufficient USDC — returns 402 Payment Required
- Malformed request body missing required fields — returns 400 Bad Request
- Model temporarily unavailable upstream — returns 502 or 503
- Rate limiting by the underlying Cloudflare Worker — returns 429 Too Many Requests
- Invalid message format not conforming to OpenAI chat schema — returns 422 or 400

## How this service works

LLM inference API: OpenAI-compatible chat completions for 136 AI models (Claude, GPT, Gemini, Grok, DeepSeek, Qwen, Kimi, GLM), paid per call in USDC on Base with x402. No account, no API key, automatic refund if the model fails.

## Output

Returns an OpenAI-compatible chat completion JSON object containing the assistant's reply text, the model name (qwen/qwen3.8-max), token usage breakdown (prompt, completion, total), finish reason, and a unique completion ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Optional: fixed by the route (qwen/qwen3.8-max)"
  },
  "tools": {
   "type": "array"
  },
  "stream": {
   "type": "boolean",
   "description": "true: server-sent events after payment"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant",
       "tool",
       "developer"
      ],
      "type": "string"
     },
     "content": {
      "type": [
       "string",
       "array",
       "null"
      ]
     }
    }
   },
   "minItems": 1
  },
  "max_tokens": {
   "type": "integer",
   "maximum": 16384,
   "minimum": 1,
   "description": "Optional, default 4096"
  },
  "temperature": {
   "type": "number",
   "maximum": 2,
   "minimum": 0
  },
  "response_format": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-7f3c2a91",
  "model": "qwen/qwen3.8-max",
  "usage": {
   "total_tokens": 10,
   "prompt_tokens": 9,
   "completion_tokens": 1
  },
  "object": "chat.completion",
  "choices": [
   {
    "index": 0,
    "message": {
     "role": "assistant",
     "content": "OK"
    },
    "finish_reason": "stop"
   }
  ],
  "created": 1791979200
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/model-access-gateway-qwen3-8-max-chat-completions-9b7ac92f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402-arb.rosariovitale0096.workers.dev](https://www.zero.xyz/host/agent402-arb.rosariovitale0096.workers.dev/llms.txt)