Nemotron 3.5 Lightning (free) API: toman pricing and code
nvidia/nemotron-3.5-lightning:free
Free · shared capacitytoolsreasoningYou are billed for the usage the request actually reported. Prices follow the market.Pricing and top-ups
Nemotron 3.5 Lightning (free) example: a multi-step problem with reasoning
The example is picked from this model's own capabilities. Drop in your key and it runs as is.
from openai import OpenAI
client = OpenAI(base_url="https://api.uttapen.ir/v1", api_key="sk-up-…")
resp = client.chat.completions.create(
model="nvidia/nemotron-3.5-lightning:free",
messages=[{"role": "user", "content": (
"A shop has 3 warehouses. A ships 120 orders a day, B ships 85 and C ships 40. "
"If C closes and its load is split between A and B in proportion to their capacity, how many does each ship a day? "
"Work through it step by step and give just the two numbers at the end."
)}],
reasoning_effort="medium", # low | medium | high
)
print(resp.choices[0].message.content)
# reasoning tokens count as output tokens too:
print(resp.usage.completion_tokens_details)curl https://api.uttapen.ir/v1/chat/completions \
-H "Authorization: Bearer sk-up-…" \
-H "Content-Type: application/json" \
-d '{
"model": "nvidia/nemotron-3.5-lightning:free",
"messages": [{"role": "user", "content": "120 and 85 daily orders split across two warehouses; work through it step by step."}],
"reasoning": {"effort": "medium"}
}'import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://api.uttapen.ir/v1", apiKey: "sk-up-…" });
const resp = await client.chat.completions.create({
model: "nvidia/nemotron-3.5-lightning:free",
messages: [{ role: "user", content: "120 and 85 daily orders are split between two warehouses; work through it step by step and give just the two numbers at the end." }],
reasoning_effort: "medium",
});
console.log(resp.choices[0].message.content);
console.log(resp.usage.completion_tokens_details);What is Nemotron 3.5 Lightning (free) good for?
Nemotron 3.5 Lightning (free) is one of NVIDIA's models. Put "nvidia/nemotron-3.5-lightning:free" in the model field and the rest of your code stays as it is. Nemotron 3.5 Lightning (free) keeps 1,000,000 tokens in view at once, and that number is what caps the conversation history in your product. A single response can run to 65,536 tokens. It is free: nothing leaves your wallet. The capacity is shared across all users and there is a daily cap per account, so treat it as a testing lane rather than a production dependency.
Capabilities available on this id: it supports tool calling, so it can invoke your own functions with valid arguments; it has a reasoning mode that pays off on multi-step problems, maths and debugging. All of it works through the standard parameters of the official OpenAI SDK — no custom client, no wrapper. Keep in mind that reasoning tokens are output tokens and do appear on the bill.
For a back-of-envelope figure: about 0 toman per 1,000-word exchange (0 in, 0 out, per 1M tokens). You are always charged for the usage the request actually reported, never for the estimate, and a failed request costs nothing.
The closest alternative with the same capabilities from a different provider is North Mini Code (free), and its context window is larger. Both run on the same key and the same code, so trying the other one is a single string change.
This id gets confused with "nvidia/nemotron-3.5-lightning", because the underlying model is the same. The difference is the suffix: "free" against the standard variant. The context windows differ too: 1,000,000 against 262,144 tokens. Maximum answer length differs as well: 65,536 against 131,072 tokens. On parameters the other takes frequency_penalty, logit_bias, logprobs, min_p.
NVIDIA has 10 models in our catalogue; the cheapest is Nemotron 3 Nano 30B A3B at 94 toman per thousand words and the dearest Nemotron 3 Ultra at 1,414. It does not support response_format, structured_outputs, which most models here do, so test before switching if your code relies on them. By context size the nearest option from another provider is Nova 2 Lite at 1,000,000 tokens.
What to use it for: proving an idea works before you spend anything, logic puzzles and code review, agents that reach out to APIs and databases, analysing a long document or codebase in one request.
NVIDIA Nemotron 3.5 Lightning is an open mixture-of-experts model from NVIDIA, with 3B active parameters out of 30B total. It is suited for high-throughput agentic workloads and specialized tasks that...
Three real jobs, priced on this model
Each figure is derived from the prices above and moves when they do.
| Job | Tokens | Cost |
|---|---|---|
| One chat turn with a medium history | 1,500 in + 400 out | 0 toman |
| Summarising a ten-page document | 4,000 in + 600 out | 0 toman |
| Classifying a thousand short rows | 120,000 in + 20,000 out | 0 toman |
Other variants of this model
Same core model, different execution terms and different price. This page is the free variant.
| Variant | Model id | Output / 1M | Context |
|---|---|---|---|
| standard | nvidia/nemotron-3.5-lightning | 58,025 | 262,144 |
Put the variant's id verbatim in the model field; nothing else in your code changes.
Frequently asked
- How do I call Nemotron 3.5 Lightning (free) from Iran?
- Sign up with your mobile number, top the wallet up in toman, create an API key, then in the official OpenAI SDK point base_url at https://api.uttapen.ir/v1 and set model to "nvidia/nemotron-3.5-lightning:free". Nothing else in your code changes.
- What does Nemotron 3.5 Lightning (free) cost in toman?
- 0 toman per 1M input tokens and 0 toman per 1M output tokens; a 1,000-word request is around 0 toman. You pay for the usage that request actually reported, and a failed request costs nothing.
- How much input does Nemotron 3.5 Lightning (free) take?
- Up to 1,000,000 tokens per request, roughly 750k words. A single answer can reach 65,536 tokens.
- Does Nemotron 3.5 Lightning (free) support streaming and tool calling?
- Streaming (stream=true) works on every model here. This one supports tool calling in the standard OpenAI shape.
- What are the limits on a free model?
- Free models have a daily per-user cap and their capacity is shared with everyone else. When the shared pool is exhausted the request is refused with a clear error and your wallet is untouched.