Name: OpenAI: GPT-5.6 Terra
Author: openai

Question 1

What is GPT-5.6 Terra?

Accepted Answer

GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic tasks where capability and cost need to be balanced, offering strong performance at roughly half the cost of Sol.

Question 2

How much does GPT-5.6 Terra cost?

Accepted Answer

GPT-5.6 Terra costs $1.00/M input tokens and $6.00/M output tokens, with separate rates for Cache Read at $0.10/M tokens and Cache Write at $1.25/M tokens.

Question 3

What is the context length of GPT-5.6 Terra?

Accepted Answer

GPT-5.6 Terra has a 1,050,000 token context window. It supports up to 128,000 completion tokens.

Question 4

Does GPT-5.6 Terra support tool calling and structured outputs?

Accepted Answer

Yes. GPT-5.6 Terra accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

Question 5

What inputs and outputs does GPT-5.6 Terra support?

Accepted Answer

GPT-5.6 Terra accepts files such as PDFs, images and text as input and returns text.

Question 6

Which providers serve GPT-5.6 Terra?

Accepted Answer

GPT-5.6 Terra is served by 3 providers on OpenRouter: OpenAI, Amazon Bedrock (US) and Azure (EU). Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

Question 7

When was GPT-5.6 Terra released?

Accepted Answer

GPT-5.6 Terra was released on 2026-07-09. Its knowledge cutoff is 2026-02-16.

OpenAI: GPT-5.6 Terra

openai/gpt-5.6-terra

OpenAI: GPT-5.6 Terra

openai/gpt-5.6-terra

Frequently asked questions

Frequently asked questions