OpenAI · Model guide

GPT-5.6 Terra

Q: What is GPT-5.6 Terra?

GPT-5.6 Terra is available on CrossModel as openai/gpt-5.6-terra. It has a 1M-token context window and can return up to 128K tokens per request.

Q: How much does GPT-5.6 Terra cost?

Currently $ 2.00 per 1M input tokens and $ 12.00 per 1M output tokens. Cached input is billed at $ 0.20 per 1M.

Q: Does GPT-5.6 Terra support tool calling and structured output?

Tool calling: Supported · Structured output (JSON): Supported · Image input: Supported · Streaming: Supported · Thinking mode: Supported

Q: Which endpoint do I call?

For text models, OpenAI Chat Completions (/v1/chat/completions), OpenAI Responses (/v1/responses) and Anthropic Messages (/v1/messages) all work — pick whichever your SDK already speaks.

Q: Can I try it without writing code?

Yes. Sign in and open the Playground on this page to chat with the model directly — no API key needed. Usage is billed from your wallet at the normal rate.

Compare

openai/gpt-5.6-terra

GPT-5.6 Terra balances intelligence and latency for everyday production agents. It roughly replaces the mini tier from earlier GPT-5 families while retaining the full 1.05M context and broad GPT-5.6 tool surface.

Modalities

Context

Max output

128K

Price / 1M tokens

$ 2.00in$ 12.00out

StreamingTool callingJSON outputImage inputThinking mode

What this model is good at

What the vendor positions it for, and which of our models to reach for instead.

VendorThe balanced GPT-5.6 tier for everyday work and production agents.source

Best for

Everyday knowledge work · Balances strong professional-work performance with lower cost than Sol.(vendor claim)source
Cost-aware agentic coding · Retains the GPT-5.6 coding and tool surface at a lower token price.(vendor claim)source

Neighbouring models

openai/gpt-5.6-solstronger —Use Sol when frontier quality matters more than price.
openai/gpt-5.6-lunacheaper —Use Luna for high-volume, cost-sensitive execution.

Compare them side by side →

Pricing and billing

Tiered pricing: the rate changes once the input passes the threshold.

Price / 1M tokens by input size	Input < 272.0K	Input ≥ 272.0K
Input	$ 2.00	$ 4.00
Output	$ 12.00	$ 18.00
Cache read	$ 0.20	$ 0.40
Cache write	$ 2.50	$ 5.00

Estimate a request

Input tokens10,000

Output tokens2,000

Cache hit rate0%

At this input size you are on the Input < 272.0K tier.

$ 0.0440

Estimated cost per request

10.0K × $ 2.00
+ 2.0K × $ 12.00

≈ $ 44.00 per 1,000 requests

Capabilities and limits

What CrossModel guarantees across every route this model can take right now.

Context window: 1.1M tokens
Max output: 128.0K tokens
Input / output modalities: Text + Image → Text
Streaming: Supported
Tool calling: Supported
Structured output (JSON): Supported
Image input: Supported
Thinking mode: Supported· always on
Reasoning effort: none · low · medium · high · xhigh · max
Available endpoints: /v1/chat/completions · /v1/responses · /v1/messages

First-party sources:Specsdevelopers.openai.comCapabilitiesdevelopers.openai.com 1 developers.openai.com 2

Published benchmarks

Scores the vendor reported, with the evaluation setup each one came from.

Agentic coding

Terminal-Bench 2.1
pass_rate·OpenAI · 2026-07-09effort maxsetup not fully disclosed
87.4%

Agentic search

BrowseComp (with tools)
accuracy·OpenAI · 2026-07-09effort maxsetup not fully disclosed
87.5%

Agentic work

Agents' Last Exam
score·OpenAI · 2026-07-09effort maxsetup not fully disclosed
50.4%

Coding

SWE-Bench Pro (Public)
pass_rate·OpenAI · 2026-07-09effort maxsetup not fully disclosed
63.4%

Computer use

OSWorld 2.0
success_rate·OpenAI · 2026-07-09effort maxsetup not fully disclosed
50.2%

Long context

OpenAI MRCR v2 8-needle 512K–1M
accuracy·OpenAI · 2026-07-09effort maxsetup not fully disclosed
72.5%

Multimodal reasoning

MMMU Pro (with tools)
accuracy·OpenAI · 2026-07-09effort maxsetup not fully disclosed
82%

Scientific reasoning

GPQA Diamond
accuracy·OpenAI · 2026-07-09effort maxsetup not fully disclosed
92.9%

Tool use

Toolathlon
score·OpenAI · 2026-07-09effort maxsetup not fully disclosed
53.1%

Vendor-reported numbers, not CrossModel measurements. Scores are only comparable when the benchmark version, metric and evaluation setup match, so nothing here is averaged or ranked.

Use it in your tools

Point the base URL at CrossModel and paste this model ID — every tool below has a setup guide.

Claude Code

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Cursor

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Cline

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Codex

OpenAI's coding agent for ChatGPT desktop and the terminal

OpenCode

Open-source terminal coding assistant

Zed

High-performance, AI-native code editor

Open WebUI

Open-source, self-hosted AI chat interface

Continue

Open-source AI coding assistant for VS Code & JetBrains

See all integration guides →

Frequently asked questions

What is GPT-5.6 Terra?

GPT-5.6 Terra is available on CrossModel as openai/gpt-5.6-terra. It has a 1M-token context window and can return up to 128K tokens per request.

How much does GPT-5.6 Terra cost?

Currently $ 2.00 per 1M input tokens and $ 12.00 per 1M output tokens. Cached input is billed at $ 0.20 per 1M.

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

Tool calling: Supported · Structured output (JSON): Supported · Image input: Supported · Streaming: Supported · Thinking mode: Supported

Which endpoint do I call?

For text models, OpenAI Chat Completions (/v1/chat/completions), OpenAI Responses (/v1/responses) and Anthropic Messages (/v1/messages) all work — pick whichever your SDK already speaks.

Can I try it without writing code?