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

$2.50/1M input, $0.25/1M cached input, and $15/1M 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
$2.50 input, $0.25 cached input, and $15 output per 1 million tokens
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: $2.50/1M input, $0.25/1M cached input, and $15/1M output tokens; prompts above 272K input use 2x input and 1.5x output rates; cache writes cost 1.25x uncached input
Platform: OpenAI

Related Keywords

GPT-5.6 Terragpt-5.6-terraOpenAI GPT-5.6GPT-5.6 Terra pricingGPT-5.6 Terra context windowGPT-5.6 API pricingcost-effective reasoning model

Related Models

GPT-5.6 Luna

OpenAI's generally available GPT-5.6 tier for cost-sensitive, high-volume workloads and lighter reasoning or coding tasks.

GPT-5.6 Sol

OpenAI's generally available frontier GPT-5.6 model for complex professional work, hard reasoning, coding, and scientific tasks.

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