# OpenAI GPT 5.6 Sol Chat Completions (via mm.family x402)

> OpenAI GPT 5.6 Sol Chat Completions (via mm.family x402) is a paid API for AI agents from openai.mm.family, paid per call via x402, $0.001024/call, status unknown (last checked 2026-10-03).

Runs GPT-5.6-Sol chat completions (up to 272K input tokens) billed per-call in USDC via the x402 payment protocol, with Flex/Standard/Fast service tiers and configurable reasoning levels.

## Facts

- Endpoint: POST https://openai.mm.family/x402/v1/models/gpt-5.6-sol/chat/completions?utm_source=zero.xyz
- Price: $0.001024/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-03
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openai-gpt-5-6-sol-chat-completions-via-mm-family-x402-c30959d1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__tB08k07rb8F9mNL7K3ug

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 openai-gpt-5-6-sol-chat-completions-via-mm-family-x402-c30959d1 -d '<json body>'
```

Example prompt: Send this conversation to GPT-5.6-Sol using the Standard service tier, up to 1000 output tokens: system says 'You are a helpful assistant', user says 'Explain the difference between supervised and unsupervised learning in two paragraphs.'

## When to prefer this

Choose this endpoint when you need OpenAI's GPT-5.6-Sol model specifically, require up to 272K input tokens, want to pay per-call in USDC via x402 (no subscription), and need control over service tier (Flex for lowest cost, Fast for lowest latency) or reasoning intensity level. Prefer over generic OpenAI API when crypto-native micropayment billing is required or when the caller lacks an OpenAI API key but holds USDC.

## Known failure modes

- Insufficient USDC balance for the x402 payment — returns 402 Payment Required
- Input tokens exceed 272K context limit — returns 400 with token count error
- Invalid model variant string — returns 400 validation error
- Unsupported service_tier value — returns 400 enum error
- Rate limiting or upstream OpenAI unavailability — returns 429 or 503
- max_tokens too large for chosen tier — may return 400 or truncated response

## How this service works

gpt-5.6-sol: OpenAI GPT 5.6 Sol (<=272K input tokens) chat completions, paid per call in USDC. Per 1M tokens in/out: Flex (default) 2.0/10.0, Standard 4.0/20.0, Fast 8.0/40.0; pick with service_tier. Plus $0.0005 (Base) or $0.0005 (Solana) per call; the quote charges input plus 10% of max_tokens. Levels: none, low, medium, high, xhigh (model gpt-5.6-sol:<level>). Empty answers are free. Rates: https://openai.mm.family/x402/pricing

## Output

A JSON chat completion object containing the assistant's reply text, finish reason (e.g. 'stop'), prompt and completion token counts, model name, service tier used, and a completion ID — matching the OpenAI chat completions response format.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "enum": [
    "gpt-5.6-sol",
    "gpt-5.6-sol:none",
    "gpt-5.6-sol:low",
    "gpt-5.6-sol:medium",
    "gpt-5.6-sol:high",
    "gpt-5.6-sol:xhigh"
   ],
   "type": "string"
  },
  "tools": {
   "type": "array"
  },
  "stream": {
   "type": "boolean"
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "type": "string"
     },
     "content": {
      "type": "string"
     }
    }
   }
  },
  "max_tokens": {
   "type": "integer"
  },
  "service_tier": {
   "enum": [
    "flex",
    "default",
    "standard",
    "auto",
    "fast",
    "priority"
   ],
   "type": "string"
  },
  "response_format": {
   "type": "object"
  },
  "reasoning_effort": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-x",
  "model": "gpt-5.6-sol",
  "usage": {
   "total_tokens": 9,
   "prompt_tokens": 8,
   "completion_tokens": 1
  },
  "object": "chat.completion",
  "choices": [
   {
    "index": 0,
    "message": {
     "role": "assistant",
     "content": "Hello",
     "refusal": null
    },
    "finish_reason": "stop"
   }
  ],
  "service_tier": "flex"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/openai-gpt-5-6-sol-chat-completions-via-mm-family-x402-c30959d1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from openai.mm.family](https://www.zero.xyz/host/openai.mm.family/llms.txt)