BlockRun
Get started
Back to Models

Gemma 4 31B (Free)

nvidia/gemma-4-31b

nvidia

Google's Gemma 4 31B instruction-tuned, open weights, hosted free by NVIDIA.

Code Examples

from blockrun_llm import LLMClient

client = LLMClient()  # Uses BLOCKRUN_WALLET_KEY (never sent to server)
response = client.chat("nvidia/gemma-4-31b", "Hello!")
import { LLMClient } from '@blockrun/llm';

const client = new LLMClient();  // Uses BLOCKRUN_WALLET_KEY (never sent to server)
const response = await client.chat('nvidia/gemma-4-31b', 'Hello!');
curl -X POST https://blockrun.ai/api/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "PAYMENT-SIGNATURE: <payment_header>" \
  -d '{
    "model": "nvidia/gemma-4-31b",
    "messages": [{"role": "user", "content": "Hello!"}],
    "max_tokens": 1024
  }'

On BlockRun since 2026-10-02. Measured on BlockRun: fewer than 100 calls to Gemma 4 31B (Free) this week — price only.

Pricing

InputFree / 1M tokens
OutputFree / 1M tokens
Context131K tokens
Max Output16K tokens

Free model — no payment or wallet required.

Payment

Network
Base
Currency
USDC
Protocol
x402

Pay per request with USDC on Base. No subscription required.

Try It

Send a message to try Gemma 4 31B (Free)

Connect your wallet to enable payments

About NVIDIA Gemma 4 31B (Free)

Gemma 4 31B (Free) is a reasoning model from NVIDIA with a 131K-token context window and up to 16K tokens of output per call. It is free to call here — no payment header and no wallet. It is served through BlockRun's OpenAI-compatible API, so it can be called without an account, an API key, or a subscription.

What it costs

Gemma 4 31B (Free) is free to call on BlockRun. No payment header is required, no wallet needs funding, and no API key is issued — requests are rate limited per IP rather than billed. It is a practical way to develop against the API surface before moving production traffic onto a paid model.

Specifications

Context window
131,072 tokens
Maximum output
16,384 tokens
API compatibility
OpenAI-compatible
Payment
Free — no payment required
Categories
chat, reasoning

Calling it from your code

Pass nvidia/gemma-4-31b as the model field. Because the endpoint mirrors the OpenAI chat completions schema, any existing OpenAI client works by changing the base URL — streaming, tool use, and multi-turn messages all behave the same way.

The first request returns a 402 carrying the exact price; a signed retry runs it, and client libraries fold the two into one call — how the payment works. See the documentation for request and response shapes, the LLM API page for every model on this endpoint, or browse the full catalog of 87 chat models to compare alternatives.

Related models

Every model on BlockRun is reached through the same endpoint and the same payment flow, so switching is a one-line change to the model field. These are the closest alternatives to Gemma 4 31B (Free):

Two ways to run this

Get an API key

Sign in, get a key, and call the same endpoints with usage billed to your account. For teams that want one invoice instead of one wallet.

Get an API key 

Or let your agent pay per call, in USDC

No account, no API key. Three steps, and the last one is the request this page is about.

  1. 01
    Point your agent at BlockRun

    Install ClawRouter, or add the BlockRun MCP server to Claude Code, Cursor, Codex or OpenClaw. Any OpenAI-compatible client works too — change the base URL, nothing else.

    curl -fsSL https://blockrun.ai/ClawRouter-update | bash
  2. 02
    Fund a wallet with USDC

    Send USDC to a wallet on Base or Solana. There is no account to create and no API key to issue: the wallet is the account, and it pays per call.

  3. 03
    Call Gemma 4 31B (Free)

    The first call returns HTTP 402 with the exact price, your agent signs it, and the answer comes back. Payment settles on-chain; nothing is charged if the call fails.

    curl -X POST https://blockrun.ai/api/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model": "nvidia/gemma-4-31b", "messages": [{"role": "user", "content": "Hello!"}]}'
ClawRouter setup →How paying per call works →

Explore everything on BlockRun