# Model Access Gateway – GPT-6.1-Sol via x402

> Model Access Gateway – GPT-6.1-Sol via x402 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 against the GPT-6.1-Sol 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/gpt-6.1-sol?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-gpt-6-1-sol-via-x402-afd8e8d3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fKdwElLoepTbH-M-4LINV

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-gpt-6-1-sol-via-x402-afd8e8d3 -d '<json body>'
```

Example prompt: Send this conversation to the GPT-6.1-Sol model and get back a chat completion — pay for it automatically with USDC on Base, no API key needed: messages are [{"role":"user","content":"Summarize the benefits of exercise in two sentences."}].

## When to prefer this

Choose this endpoint when you need OpenAI-compatible chat completions with no account setup, no API key management, and automatic per-request payment in USDC on Base via x402. Ideal for agentic and autonomous workflows where the agent pays for its own inference, for one-off tasks where a subscription is overkill, or when integrating crypto-native payment rails directly into an AI pipeline. Prefer alternatives (direct OpenAI API, Anthropic, etc.) if you already have API keys, need guaranteed SLA, or need models not available through this gateway.

## Known failure modes

- Payment failure: x402 micropayment rejected or insufficient USDC balance on Base — request fails with 402 Payment Required
- Invalid body format: missing required 'input' wrapper or incorrect bodyType enum value — returns 400 Bad Request
- Model unavailable: the specific model slug (gpt-6.1-sol) is not available — returns 404 or 503
- Malformed messages array: chat messages not formatted correctly per OpenAI spec — may return 422 or garbled output
- Rate limiting: downstream provider throttles requests — returns 429 Too Many Requests

## How this service works

GPT-6.1 Sol API (openai/gpt-6.1-sol): LLM inference via OpenAI-compatible chat completions, pay per call in USDC on Base with x402. No API key, no account. Suited for AI agents and scripts that need GPT-6.1 Sol on demand. When listed, this request cost 30% less than the same request on BlockRun. Streaming and function calling supported. Exact price in the 402 quote before payment; automatic refund if the model fails to answer.

## Output

Returns a standard OpenAI chat.completion JSON object containing the assistant's reply message, the model used (openai/gpt-6.1-sol), 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 (openai/gpt-6.1-sol)"
  },
  "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": "openai/gpt-6.1-sol",
  "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-gpt-6-1-sol-via-x402-afd8e8d3/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)