GPT-5.6 Terra is the balanced model in OpenAI's GPT-5.6 series, sitting between the Sol flagship and the cost-efficient Luna tier to give the best quality-to-cost ratio for everyday production work. It handles day-to-day coding, reasoning, tool use, and agentic workflows with a 1.05M-token context window and up to 128K output tokens, holding up well on long documents, large codebases, and multi-turn sessions. It accepts text, image, and file inputs with text output, supports configurable reasoning effort to tune the intelligence / latency / cost tradeoff, and is a first-class OpenAI Responses model with native tool calling and structured outputs. Terra is a strong default when Sol is more than the task needs but Luna is not quite enough — general assistants, mid-complexity coding, and high-throughput agent pipelines.
OpenAI-compatible — keep the SDK you already use
https://api.orcarouter.ai/v1from openai import OpenAI
client = OpenAI(
base_url="https://api.orcarouter.ai/v1",
api_key="$ORCAROUTER_API_KEY",
)
response = client.chat.completions.create(
model="openai/gpt-5.6-terra",
messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools| Tier | Input / 1M tokens | Output / 1M tokens | Cache read / 1M | Cache write / 1M |
|---|---|---|---|---|
| ≤ 272K | $2.50 | $15.00 | $0.250 | $3.125 |
| ≤ ∞ | $5.00 | $22.50 | $0.500 | $6.25 |
| Tier selected by input token count of each request | ||||
Estimate based on list price
Tiered pricing — this estimate uses base-tier rates.
Estimate only — actual token counts depend on the provider's tokenizer.
GET /api/public/models/openai/gpt-5.6-terraOpen @misc{orcarouter_gpt_5_6_terra,
title = {GPT-5.6 Terra API},
author = {OpenAI},
year = {2026},
howpublished = {OrcaRouter},
url = {https://www.orcarouter.ai/models/openai/gpt-5.6-terra}
}OpenAI. (2026). GPT-5.6 Terra API. OrcaRouter. https://www.orcarouter.ai/models/openai/gpt-5.6-terra