openai/gpt-5.6-terra
Balanced GPT-5.6 quality and cost for production workloads.
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Add password reset validation.GPT-5.6 Terra is the middle tier of the GPT-5.6 family, released by OpenAI on July 9, 2026. OpenAI's model page describes it as balancing intelligence and cost and says it roughly corresponds to the mini tier of earlier GPT-5 families. OpenAI's deprecations table names it as the replacement for several older models, including o4-mini, gpt-5-mini and gpt-3.5-turbo.
Structurally it matches Sol: a 1.05M-token context window (up to 922K input), 128K max output, text and image input, and a knowledge cutoff of February 16, 2026; reasoning effort from none to max with medium as the default, plus Pro mode; and the GPT-5.6 default of carrying reasoning across turns, with Sol, Terra and Luna able to reuse each other's reasoning. On RouteMux it supports tool calling and explicit prompt caching over OpenAI Chat Completions, OpenAI Responses and Anthropic Messages.
The practical way to use this generation is to default to Terra and escalate. The three tiers share a request shape, moving a hard request to Sol is a model-name change, and reasoning carries over between tiers, so you find out quickly whether a task needed Sol or just a better prompt. In the GPT-6 generation the Terra tier is GPT-6.1 Terra, released October 26, 2026, and OpenAI's GPT-6 guide suggests comparing the two on representative images and workflows at the same reasoning effort before migrating. Stay on 5.6 Terra when one conversation moves between the 5.6 tiers and should keep its reasoning, or when your pipeline is tuned to it.
At the standard tier (input up to 272K tokens) it bills $0.3 per 1M input tokens and $1.8 per 1M output tokens, with cached input at $0.03 per 1M tokens. OpenAI lists $2, $12 and $0.2 for the same three.
Prices verified 2026-10-18
Fast $0.6 / $3.6 /M
Cache read $0.03/M · Cache write $0.375/M
| Tier | Input | Cache read | Cache write | Output |
|---|---|---|---|---|
| Standard ≤272K | $0.3 | $0.03 | $0.375 | $1.8 |
| Standard >272K | $0.6 | $0.06 | $0.75 | $2.7 |
| Priority ≤272K | $0.6 | $0.06 | $0.75 | $3.6 |
| Priority >272K | $1.2 | $0.12 | $1.5 | $5.4 |
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Use any of these IDs to call this model via the API.
openai/gpt-5.6-terraReplace the ROUTEMUX_KEY placeholder with your API key. Create one →
from openai import OpenAI
client = OpenAI(
base_url="https://api.routemux.com/v1",
api_key="<ROUTEMUX_KEY>",
)
completion = client.chat.completions.create(
model="openai/gpt-5.6-terra",
messages=[{"role": "user", "content": "What is the meaning of life?"}],
)
print(completion.choices[0].message.content)Balanced GPT-5.6 quality and cost for production workloads.
GPT-5.6 Terra supports a context window of up to 1.05M tokens, with up to 128K output tokens per request.
Through RouteMux, GPT-5.6 Terra costs $0.3 for input and $1.8 for output (USD per 1M tokens), below the official list price.
GPT-5.6 Terra is OpenAI-compatible: point your base URL at RouteMux and set the model field to openai/gpt-5.6-terra — no code changes needed.
GPT-5.6 Terra accepts text, image as input and produces text as output.
GPT-5.6 Terra was released on July 9, 2026.
Reviewed by the RouteMux team on 2026-10-24
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