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…
Full description at the source- Input price
- per 1M tokens
- Output price
- per 1M tokens
- Context
- 262.1K16.4K max output
- Cost / request
- 8K in · 500 out
01Routes and pricing
02Capabilities
- Input
- text
- Output
- text
- Context
- 262.1K
- Max output
- 16.4K
ReasoningTool callingStructured outputJSON modeSeeded sampling
03Quick start
Call it with your RProuter key
Any OpenAI-compatible SDK works. Point it at the RProuter base URL from your API keys page and use this model ID.
Catalog source: openrouter.ai · checked 2026-09-16
const response = await client.chat.completions.create({
model: "nvidia/nemotron-3-ultra-550b-a55b",
messages: [{ role: "user", content: "A story begins…" }],
max_tokens: 500,
stream: true,
});
for await (const chunk of response) {
process.stdout.write(chunk.choices[0]?.delta?.content ?? "");
}