# Model Access Gateway – Qwen3.8-Max Chat Completions (x402, USDC)

> Model Access Gateway – Qwen3.8-Max Chat Completions (x402, USDC) is a paid API for AI agents from modelaccessgateway.com, paid per call via x402, $0.0014/call, status unknown (last checked 2026-10-16).

Runs OpenAI-compatible chat completions using Alibaba's Qwen3.8-Max model, billed per call in USDC on Base via x402 — no API key or account required.

## Facts

- Endpoint: POST https://modelaccessgateway.com/llm/qwen3.8-max?utm_source=zero.xyz
- Price: $0.0014/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/model-access-gateway-qwen3-8-max-chat-completions-x402-usdc-96e7569e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eauu-nHp9Dv_XhBq-Kegu

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-x402-usdc-96e7569e -d '<json body>'
```

Example prompt: Ask Qwen3.8-Max to explain the difference between supervised and unsupervised learning in 3 bullet points — pay per call in USDC, no API key needed, up to 512 tokens.

## When to prefer this

Choose this endpoint when you need Qwen3.8-Max specifically (Alibaba's flagship reasoning-optimized model) without committing to a subscription or managing API keys. Ideal for AI agents that need pay-as-you-go LLM inference settled in USDC on Base, for sporadic or bursty workloads, or when operating in environments where traditional API key management is impractical. Prefer over OpenAI/Anthropic direct APIs when you want crypto-native micropayment billing or need to avoid account creation overhead.

## Known failure modes

- Payment failure or insufficient USDC balance — x402 payment rejected, no completion returned but automatic refund issued
- Model unavailable upstream — gateway returns error, automatic refund triggered
- max_tokens exceeded allowed range (1–16384) — validation error
- Empty or malformed messages array — request rejected with 400-level error
- Temperature out of range (0–2) — validation error
- Stream requested but client disconnects before completion

## 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 message, finish reason (stop/length/tool_calls), and token usage breakdown (prompt, completion, total tokens). Streaming mode delivers server-sent events incrementally after payment is settled.

## 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-x402-usdc-96e7569e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from modelaccessgateway.com](https://www.zero.xyz/host/modelaccessgateway.com/llms.txt)