GPT-5.6 Terra

GPT-5.6 Terra is OpenAI's generally available GPT-5.6 tier for workloads that balance intelligence, coding capability, and cost.

Platform: OpenAI

Language ModelReasoningCodingOpenAI

OpenAI-hosted

$2/1M input, $0.20/1M cached input, and $12/1M output tokens; prompts above 272K input use 2x input and 1.5x output rates; cache writes cost 1.25x uncached input

Commercial

🚀Function Overview

The balanced GPT-5.6 tier for everyday reasoning, coding, and knowledge work that does not require Sol-level capability or pricing.

Key Features

Official OpenAI GPT-5.6 family member with model ID gpt-5.6-terra
OpenAI's balanced GPT-5.6 tier, roughly corresponding to earlier mini tiers
Generally available across the OpenAI API, ChatGPT, and Codex
1,050,000-token context window and 128,000-token maximum output
February 16, 2026 knowledge cutoff with reasoning-token support
$2 input, $0.20 cached input, and $12 output per 1 million tokens after OpenAI's July 30 price update
Prompts above 272K input tokens use 2x input and 1.5x output rates; cache writes use 1.25x uncached input

Use Cases

•Cost-controlled GPT-5.6 family experiments
•Coding or analysis tasks that need more capability than a cheap baseline but do not justify Sol
•A/B routing between Terra, Luna, Sol, and older OpenAI models
•Production routing with explicit long-context and cache-write cost checks

⚙️Input Parameters

messages

array

Chat or reasoning task messages sent to the OpenAI API or supported OpenAI product surface.

model

string

Use gpt-5.6-terra for the balanced GPT-5.6 tier in the OpenAI API.

💡Usage Examples

Example 1

Input Parameters

{
  "model": "gpt-5.6-terra",
  "messages": [
    {
      "role": "user",
      "content": "Summarize the risk tradeoffs before escalating this coding task to GPT-5.6 Sol."
    }
  ]
}

Output Results

A response from GPT-5.6 Terra. Validate quality and total cost against Luna and Sol before choosing a production route.

Quick Actions

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Technical Specifications

Hardware Type: OpenAI-hosted
Commercial Use: Supported
Pricing: $2/1M input, $0.20/1M cached input, and $12/1M output tokens; prompts above 272K input use 2x input and 1.5x output rates; cache writes cost 1.25x uncached input
Platform: OpenAI