# Model Access Gateway – Mistral Large 4 Chat Completions

> Model Access Gateway – Mistral Large 4 Chat Completions is a paid API for AI agents from agent402-arb.rosariovitale0096.workers.dev, paid per call via x402, $0.0023/call, status unknown (last checked 2026-10-15).

Send an OpenAI-compatible chat completion request to Mistral Large 4, paid per-request in USDC on Base via x402 with no API key required.

## Facts

- Endpoint: POST https://agent402-arb.rosariovitale0096.workers.dev/llm/mistral-large-4?utm_source=zero.xyz
- Price: $0.0023/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-mistral-large-4-chat-completions-7acbfe6a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_46Kukm0igwlI32g2hHmeV

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-mistral-large-4-chat-completions-7acbfe6a -d '<json body>'
```

Example prompt: Use Mistral Large 4 to answer this question for me — no API key setup, just pay per request in USDC: 'What are the key differences between transformer and recurrent neural network architectures?'

## When to prefer this

Choose this endpoint when you need Mistral Large 4 specifically (large context, strong reasoning) and want to avoid API key management or subscriptions — ideal for autonomous agents that pay per call in USDC on Base via x402. Prefer over OpenAI-compatible alternatives when using Mistral's flagship large model without account overhead matters.

## Known failure modes

- Insufficient USDC balance causes x402 payment failure and request is rejected
- Malformed request body (missing required fields like messages) returns a 400 error
- Model unavailable or overloaded upstream returns a 503 or timeout
- Invalid or expired x402 payment header causes authentication failure
- Exceeding token limits for Mistral Large 4 context window causes truncation or error

## 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 under choices[0].message.content, along with token usage counts (prompt, completion, total), the model identifier, a completion ID, creation timestamp, and a finish_reason (e.g. 'stop').

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "type": "string",
   "description": "Optional: fixed by the route (mistral/mistral-large-4)"
  },
  "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": "mistral/mistral-large-4",
  "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-mistral-large-4-chat-completions-7acbfe6a/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)