Nemotron 3 Ultra

NVIDIA Nemotron 3 Ultra is an open frontier-reasoning and orchestration model from NVIDIA, with 55B active parameters out of 550B total (MoE). Built on a hybrid Transformer-Mamba mixture-of-experts architecture, it supports text input and output with a context window of up to 1M tokens. It is suited for long-running agentic workflows, including agent orchestration, coding agents, deep research, and complex enterprise tasks. It is particularly strong at multi-step reasoning and planning, with high-throughput inference designed for high-volume agent pipelines. It is part of the NVIDIA Nemotron family of open models for agentic AI.

ChatNVIDIA512k tokens$0.654 / $3.9242 · 1M

nvidia/nemotron-3-ultra-550b-a55b

Context
512k tokens
Completion cap
—
Tools
Yes
JSON
Yes
Released
2026-06-04

Call it from Geek Hub

Same OpenAI SDK. Change the base URL and the model id.

curl https://api.geekhub.mx/v1/chat/completions \
  -H "Authorization: Bearer $GEEKHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nvidia/nemotron-3-ultra-550b-a55b",
    "messages": [{"role": "user", "content": "Hola"}]
  }'
Get an API key

Frequently asked questions

What is Nemotron 3 Ultra?
NVIDIA Nemotron 3 Ultra is an open frontier-reasoning and orchestration model from NVIDIA, with 55B active parameters out of 550B total (MoE). Built on a hybrid Transformer-Mamba mixture-of-experts architecture, it supports text input and output with a context window of up to 1M tokens. It is suited for long-running agentic workflows, including agent orchestration, coding agents, deep research, and complex enterprise tasks. It is particularly strong at multi-step reasoning and planning, with high-throughput inference designed for high-volume agent pipelines. It is part of the NVIDIA Nemotron family of open models for agentic AI. Nemotron 3 Ultra runs on the Geek Hub API (OpenAI-compatible). Model id: nvidia/nemotron-3-ultra-550b-a55b.
Is Nemotron 3 Ultra free?
No. Input is $0.654 per 1M tokens and output is $3.9242 per 1M tokens on Geek Hub (markup included).
What is the context length of Nemotron 3 Ultra?
Nemotron 3 Ultra has a 512k tokens context window.
Does Nemotron 3 Ultra support tool calling and structured outputs?
Nemotron 3 Ultra accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
When was Nemotron 3 Ultra released?
Nemotron 3 Ultra was released on 2026-06-04.

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