Nemotron 3 Ultra 550B A55B

Nemotron 3 Ultra 550B A55B is the largest model in the Nemotron 3 line, designed for maximum open-weight reasoning and agent accuracy. It is the successor to Nemotron 3 Nano Omni, released earlier in the same line. It has a context window of 1,000,000 tokens and a maximum output of 65,536 tokens. Weights are open. It supports reasoning mode and tool calling, and accepts and returns text. Pricing starts at $0.50 per million input tokens and $2.20 per million output tokens, with cached input at $0.10 per million tokens.

Against Nemotron 3 Nano Omni: window 256K to 1M, input $0.10 to $0.50, output $0.25 to $2.20.

Range across the hosts that serve it: up to $1.00 per 1M input tokens.

• ·1 million token context window
• ·65,536 token max output
• ·Open weights for self-hosting
• ·Reasoning mode for complex tasks
• ·Tool calling for agent workflows

• Reach for it for complex reasoning with very long context
• Reach for it for building agents that call tools
• Reach for it for open-weight deployment with large output needs

12 hosts serve this model at the price above · the maker's documentation

The registry keeps the six most recent versions of a line. Older ones stay in the file and can be surfaced without a rebuild.

What is the context window?

The context window is 1,000,000 tokens.

Does it support tool calling?

Yes, it supports tool calling.

What is the pricing?

From $0.50 per million input tokens and $2.20 per million output tokens, with cached input at $0.10 per million tokens.