Nemotron 3.5 Lightning

by nvidia · family nemotron

Facts

Release date	2026-08-11
Retired date	—
Knowledge cutoff	—
Context (max)	1,000,000
Max output	—
Modalities	text → text
Aliases	`nemotron-3.5-lightning-30b-a3b`
Open weights	yes
Description	30B-A3B MoE + Mamba-2 hybrid attention, up to 1M context; NVFP4 checkpoint fits one GPU.

Unknown values are shown as —.

Intelligence Index v4.1.1: 24 · base · Source: Artificial Analysis (accessed 2026-08-20)

Offerings

Provider	Wire ID	Endpoint	Protocol	Status	Price (USD / Mtok)	Reasoning
NVIDIA NIM API	`nvidia/nemotron-3.5-lightning-30b-a3b`	v1-chat-completions	openai-chat	ga	—	toggle · default on · returns reasoning_content
OpenCode Zen	`nemotron-3.5-lightning-free`	chat-completions	openai-chat	ga	—	toggle · default on · returns reasoning_content
OpenRouter	`nvidia/nemotron-3.5-lightning`	chat-completions	openai-chat	ga	0.08 / 0.20	effort · default on · returns reasoning_content · round-trips reasoning_content

Reasoning controls

NVIDIA NIM API· nvidia/nemotron-3.5-lightning-30b-a3b· v1-chat-completions toggle

chat_template_kwargs.enable_thinking on true · off false

toggle · default on · returns reasoning_content

OpenCode Zen· nemotron-3.5-lightning-free· chat-completions toggle

chat_template_kwargs.enable_thinking on true · off false

toggle · default on · returns reasoning_content

OpenRouter· nvidia/nemotron-3.5-lightning· chat-completions effort

reasoning.effort nonelowmedium●highxhighmax

effort · default on · returns reasoning_content · round-trips reasoning_content

Example requests

NVIDIA NIM API · openai-chat · nvidia/nemotron-3.5-lightning-30b-a3b

curl 'https://integrate.api.nvidia.com/v1/chat/completions' \
  -H 'Authorization: Bearer <YOUR_API_KEY>' \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "nvidia/nemotron-3.5-lightning-30b-a3b",
  "messages": [
    {
      "role": "user",
      "content": "Tell me about the weather."
    }
  ],
  "chat_template_kwargs": {
    "enable_thinking": true
  }
}'

Python (requests)

import requests

resp = requests.post(
    "https://integrate.api.nvidia.com/v1/chat/completions",
    headers={
      "Authorization": "Bearer <YOUR_API_KEY>",
      "Content-Type": "application/json"
    },
    json={
      "model": "nvidia/nemotron-3.5-lightning-30b-a3b",
      "messages": [
        {
          "role": "user",
          "content": "Tell me about the weather."
        }
      ],
      "chat_template_kwargs": {
        "enable_thinking": true
      }
    },
)
print(resp.json())

TypeScript (fetch)

const resp = await fetch("https://integrate.api.nvidia.com/v1/chat/completions", {
  method: "POST",
  headers: {
    "Authorization": "Bearer <YOUR_API_KEY>",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "model": "nvidia/nemotron-3.5-lightning-30b-a3b",
    "messages": [
      {
        "role": "user",
        "content": "Tell me about the weather."
      }
    ],
    "chat_template_kwargs": {
      "enable_thinking": true
    }
  }),
})
console.log(await resp.json())

OpenCode Zen · openai-chat · nemotron-3.5-lightning-free

curl 'https://opencode.ai/zen/v1/chat/completions' \
  -H 'Authorization: Bearer <YOUR_API_KEY>' \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "nemotron-3.5-lightning-free",
  "messages": [
    {
      "role": "user",
      "content": "Tell me about the weather."
    }
  ],
  "chat_template_kwargs": {
    "enable_thinking": true
  }
}'

Python (requests)

import requests

resp = requests.post(
    "https://opencode.ai/zen/v1/chat/completions",
    headers={
      "Authorization": "Bearer <YOUR_API_KEY>",
      "Content-Type": "application/json"
    },
    json={
      "model": "nemotron-3.5-lightning-free",
      "messages": [
        {
          "role": "user",
          "content": "Tell me about the weather."
        }
      ],
      "chat_template_kwargs": {
        "enable_thinking": true
      }
    },
)
print(resp.json())

TypeScript (fetch)

const resp = await fetch("https://opencode.ai/zen/v1/chat/completions", {
  method: "POST",
  headers: {
    "Authorization": "Bearer <YOUR_API_KEY>",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "model": "nemotron-3.5-lightning-free",
    "messages": [
      {
        "role": "user",
        "content": "Tell me about the weather."
      }
    ],
    "chat_template_kwargs": {
      "enable_thinking": true
    }
  }),
})
console.log(await resp.json())

OpenRouter · openai-chat · nvidia/nemotron-3.5-lightning

curl 'https://openrouter.ai/api/v1/chat/completions' \
  -H 'Authorization: Bearer <YOUR_API_KEY>' \
  -H 'Content-Type: application/json' \
  -d '{
  "model": "nvidia/nemotron-3.5-lightning",
  "messages": [
    {
      "role": "user",
      "content": "Tell me about the weather."
    }
  ],
  "reasoning": {
    "effort": "medium"
  }
}'

Python (requests)

import requests

resp = requests.post(
    "https://openrouter.ai/api/v1/chat/completions",
    headers={
      "Authorization": "Bearer <YOUR_API_KEY>",
      "Content-Type": "application/json"
    },
    json={
      "model": "nvidia/nemotron-3.5-lightning",
      "messages": [
        {
          "role": "user",
          "content": "Tell me about the weather."
        }
      ],
      "reasoning": {
        "effort": "medium"
      }
    },
)
print(resp.json())

TypeScript (fetch)

const resp = await fetch("https://openrouter.ai/api/v1/chat/completions", {
  method: "POST",
  headers: {
    "Authorization": "Bearer <YOUR_API_KEY>",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "model": "nvidia/nemotron-3.5-lightning",
    "messages": [
      {
        "role": "user",
        "content": "Tell me about the weather."
      }
    ],
    "reasoning": {
      "effort": "medium"
    }
  }),
})
console.log(await resp.json())

⚠ Responses include reasoning_content artifacts — pass them back unmodified on subsequent turns (dropping them triggers 400s or quality loss).