BlockRun

Authentication

BlockRun uses wallet-based authentication via the x402 protocol. Instead of API keys, you sign payments with your wallet.

How It Works

  1. No API Keys - Your wallet IS your authentication
  2. Local Signing - Private key never leaves your machine
  3. Pay-Per-Request - Each request is individually authorized

Setting Up Your Wallet

1. Create or Use an Existing Wallet

You can use any EVM-compatible wallet:

  • MetaMask
  • Coinbase Wallet
  • Rainbow
  • Any wallet that can export a private key

2. Fund Your Wallet with USDC

You need USDC on the Base network to pay for API requests.

Getting USDC on Base:

  1. Bridge from Ethereum using the Base Bridge
  2. Buy directly on Coinbase and withdraw to Base
  3. Swap on a DEX like Uniswap

3. Export Your Private Key

{% hint style="warning" %} Security Warning: Never share your private key. Only use it in secure environments. {% endhint %}

MetaMask:

  1. Click the three dots menu
  2. Go to Account Details
  3. Click "Show Private Key"
  4. Enter your password
  5. Copy the key

Coinbase Wallet:

  1. Go to Settings
  2. Select your wallet
  3. Choose "Show Private Key"
  4. Authenticate and copy

4. Configure the SDK

Set your private key as an environment variable:

export BLOCKRUN_WALLET_KEY=0x...

Or pass it directly to the client:

{% tabs %} {% tab title="Python" %}

from blockrun_llm import LLMClient

# From environment (recommended)
client = LLMClient()

# Or pass directly
client = LLMClient(private_key="0x...")

{% endtab %}

{% tab title="TypeScript" %}

import { LLMClient } from '@blockrun/llm';

const client = new LLMClient({
  privateKey: '0x...'
});

{% endtab %} {% endtabs %}

Security Best Practices

  1. Use Environment Variables - Never hardcode private keys
  2. Use a Dedicated Wallet - Create a separate wallet for API payments
  3. Limit Funds - Only keep enough USDC for expected usage
  4. Monitor Usage - Check your wallet transactions regularly

Checking Your Wallet

{% tabs %} {% tab title="Python" %}

from blockrun_llm import LLMClient

client = LLMClient()
print(f"Using wallet: {client.get_wallet_address()}")

{% endtab %}

{% tab title="TypeScript" %}

import { LLMClient } from '@blockrun/llm';

const client = new LLMClient({ privateKey: '0x...' });
console.log(`Using wallet: ${client.getWalletAddress()}`);

{% endtab %} {% endtabs %}