# OpenAI GPT-5.6-Terra Long Context Chat Completions (via mm.family)

> OpenAI GPT-5.6-Terra Long Context Chat Completions (via mm.family) is a paid API for AI agents from openai.mm.family, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Provides OpenAI GPT-5.6-Terra chat completions for prompts exceeding 272K input tokens, billed per call in USDC via x402 micropayment protocol

## Facts

- Endpoint: POST https://openai.mm.family/x402/v1/models/gpt-5.6-terra-long/chat/completions?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/openai-gpt-5-6-terra-long-context-chat-completions-via-mm-family-a698cf38
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jnilbqRe-H-B-AzLMlCpT

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-terra-long-context-chat-completions-via-mm-family-a698cf38 -d '<json body>'
```

Example prompt: Using the GPT-5.6-Terra long-context model with standard tier and up to 4000 output tokens, analyze this 300,000-token legal contract I'm pasting below and summarize the key obligations, risks, and termination clauses for me.

## When to prefer this

Choose this endpoint when your input context exceeds 272K tokens and you need OpenAI's GPT-5.6-Terra model specifically, especially when paying via USDC x402 micropayment and needing flexible service tier options (flex, standard, fast) with configurable reasoning effort. Prefer over shorter-context siblings when processing book-length documents, large codebases, or extended conversation histories.

## Known failure modes

- Insufficient USDC balance for the x402 micropayment results in a 402 Payment Required error
- Input context exceeding model's maximum window returns a context length error
- Invalid model level suffix (not one of none/low/medium/high/xhigh) returns a 400 bad request
- Unsupported service_tier value results in a validation error
- High load on fast/standard tier may cause timeouts for extremely large prompts

## How this service works

gpt-5.6-terra-long: OpenAI GPT 5.6 Terra (>272K input tokens) chat completions, paid per call in USDC. Per 1M tokens in/out: Flex (default) 2.0/9.0, Standard 4.0/18.0, Fast 8.0/36.0; 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-terra-long:<level>). Empty answers are free. Rates: https://openai.mm.family/x402/pricing

## Output

Returns a standard OpenAI-format chat completion JSON object containing the assistant's reply message, finish reason (e.g. 'stop'), token usage breakdown (prompt, completion, total), model name, and the service tier used. Empty answers incur no charge.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "enum": [
    "gpt-5.6-terra-long",
    "gpt-5.6-terra-long:none",
    "gpt-5.6-terra-long:low",
    "gpt-5.6-terra-long:medium",
    "gpt-5.6-terra-long:high",
    "gpt-5.6-terra-long: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-terra-long",
  "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-terra-long-context-chat-completions-via-mm-family-a698cf38/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)