GPT-6.1 Terra
gpt-6.1-terraFrontierPro planLive in the catalogGPT-6.1 Terra (2026-10-26) is the fast tier of OpenAI's GPT-6.1 line, made for tool calls, computer use, routine coding and writing; OpenAI reports it matching GPT-6 Astra on Agents' Last Exam. In our tests it wrote about four times faster than GPT-6.1 Sol, and a repeated 34K-token prompt was read almost entirely from cache, so long agent sessions stay quick. It keeps the family's 1.05M-token window, 128K output, vision, structured output and parallel tool calls. Available on Pro and higher.
- 01Fast turns for tool calls, computer use and coding
- 02About four times GPT-6.1 Sol's writing speed in our tests
- 031.05M context with vision and parallel tools
Strict, schema-faithful tool calls, enforced by the engine on every request — safe to build an agent loop on.
Thinks before it answers. Budget max_tokens generously — hidden reasoning counts against it.
Reads images — screenshots, diagrams, and UI states — inline in the conversation.
One endpoint. Served by our engine.
GPT-6.1 Terra is served through the Sideren engine — zero-downtime serving is the design target, not a status-page apology. You request it by name; everything else is our problem.
curl https://api.sideren.io/v1/messages \
-H "x-api-key: sdn_your_key" \
-H "content-type: application/json" \
-d '{
"model": "gpt-6.1-terra",
"max_tokens": 1024,
"messages": [{ "role": "user", "content": "Hello" }]
}'OpenAI-style clients work too — send the same model name to /v1/chat/completions with a Bearer key. See the docs for both dialects.
Your agent stays the same.
Its inference gets better.
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