Llama 3.1 Nemotron Ultra 253B

NVIDIAMCP Tool CallReasoning

nvidia/llama-3.1-nemotron-ultra-253bOpen Weights

Flagship Nemotron model for high-throughput reasoning and complex agents

Benchmark Pricing$0.00 / 1M in$0.00 / 1M out

Context: 128,000 tokens•Max Output: 8,192 tokens•Released: 2025-04-07

TECHNICAL SPECIFICATIONS

Context Window128,000128K tokens

Max Output8,1928.2K tokens

LicenseOpen SourceSelf-hostable

Input Modalities

Text

Function / Tool CallingSupported (MCP Ready)

Structured OutputsGuaranteed Schema

MODEL CONTEXT PROTOCOL (MCP) READINESS

✓ Llama 3.1 Nemotron Ultra 253B natively supports OpenAI / Anthropic format tool calling and is fully compatible with MCP servers and agent loops.

MCP Context Window Recommendations

With a context capacity of 128,000 tokens, this model can handle moderately large MCP tool definitions and multi-turn conversation logs comfortably.

API CALL INVOCATION EXAMPLE

// Example: Calling Llama 3.1 Nemotron Ultra 253B via OpenAI SDK
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.NVIDIA_API_KEY,
});

const response = await client.chat.completions.create({
  model: "nvidia/llama-3.1-nemotron-ultra-253b",
  messages: [{ role: "user", content: "Hello! Can you inspect MCP tools?" }],
});

console.log(response.choices[0].message.content);