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OpenAI · Frontier

GPT 5.6 Terra

Added Jul 9, 2026

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Use in the app

GPT-5.6 Terra is the balanced model in OpenAI's GPT-5.6 series, positioned between flagship Sol and cost-efficient Luna. It is suited for everyday coding, reasoning, agentic work, and general professional tasks.

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Reasoning effort
none · low · medium · high · xhigh · max
Discovery tier
Frontier

Pricing

USD per 1M tokens
Input
$2.00
Output
$12.00
Cache read
$0.20
Cache write
$2.50

Reference prices as published by the model provider. API example

Specifications

Context window
1.1M
Max output
128K
Average output (7 days)
556 tokens
Longer than 52% of 473 models

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TryGLM 5.3 Flash TEEClaude Opus 4.8MiniMax M3.1 FlashAll 3

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

Intelligence Index

42.1

Tested at max reasoning effort

Better than 87% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Coding Index

    76.7

    Composite of the coding evaluations

    Better than 94% of 168 scored models

Agentic work

  • AutomationBench-AA

    59.6%

    Workflow automation, penalized for guardrail violations

    Better than 80% of 173 scored models

  • AutomationBench-AA tasks completed

    24.5%

    Workflows finished end to end without a guardrail violation

    Better than 70% of 173 scored models

  • AA-Briefcasev1.1

    1,332 Elo

    Agentic knowledge work, rated head to head

    Better than 70% of 166 scored models

  • GDPval-AAv2.1

    1,452 Elo

    Economically valuable occupational tasks, rated head to head

    Better than 72% of 187 scored models

Document reasoning

  • GDP.pdf

    24.0%

    Professional reasoning over PDF documents, all-pass rate

    Better than 85% of 171 scored models

  • AA-LCRv1.1

    83.0%

    Reasoning across long documents

    Better than 90% of 309 scored models

  • MLCR-AA

    27.2%

    Long-context reasoning over medical records

    Better than 89% of 121 scored models

Reasoning and knowledge

  • Humanity’s Last Exam

    42.9%

    Expert-level questions across academic fields

    Better than 85% of 323 scored models

  • GPQA Diamond

    92.5%

    Graduate-level science questions

    Better than 88% of 291 scored models

  • IFBench

    71.2%

    Following precise output instructions

    Better than 74% of 215 scored models

Coding

  • Terminal-Benchv4.0

    35.4%

    Practical software engineering in a terminal

    Better than 84% of 171 scored models

  • SciCode

    55.0%

    Scientific computing in Python

    Better than 74% of 174 scored models

Legacy evaluations

  • Terminal-Bench Hard

    57.6%

    Earlier terminal task suite

    Better than 96% of 212 scored models

  • τ²-Bench Telecom

    86.3%

    Tool use in a customer-support simulation

    Better than 70% of 214 scored models

  • AA-LCR (unversioned)

    83.0%

    Long-context reasoning, earlier grading

    Better than 90% of 309 scored models

Scores from Artificial Analysis, updated Oct 26, 2026. GPT 5.6 Terra was tested at max reasoning effort; compare scores measured at the same effort.Artificial Analysis

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Throughput
245.5 tok/s
Faster than 89% of 260 models
Time to first token
2.2 s
Quicker than 70% of 260 models
Prompt cache hits
90.9%
About $0.36 per 1M input tokens with caching
Request success (24h)
100.0%
Reliable

Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.

Hourly request success · last 72 hoursLowest hour 100.0%
  • Healthy (98% or more)
  • Degraded (90–98%)
  • Down (under 90%)
  • No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.6-terra",
    "reasoning_effort": "medium",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="openai/gpt-5.6-terra",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

Other OpenAI models, starting with the same family.