BlockRun Base (EVM) Wallet Setup Guide

This guide explains how to use a Base network EVM wallet to pay for AI usage through BlockRun — no API key required.

Language: English | 中文

What is BlockRun?

BlockRun is a decentralized AI inference gateway that lets you access top AI models (Claude, GPT, Gemini, Grok, DeepSeek, etc.) by paying per request with USDC — no monthly subscriptions, no API key signups.

NOFX integrates BlockRun via the x402 micropayment protocol: each AI inference request automatically pays a small USDC fee directly from your wallet. You only pay for what you use.

Why Use BlockRun?

Prerequisites

• An EVM wallet with USDC on Base network (chain ID 8453)
• The wallet private key (hex format: 0x...)

Getting USDC on Base

1. Buy USDC on Coinbase and withdraw to Base, or
2. Bridge USDC from Ethereum using bridge.base.org, or
3. Swap on Aerodrome or Uniswap on Base

Tip: A few dollars of USDC is enough to start — each AI call costs fractions of a cent.

Step 1: Get Your Wallet Private Key

⚠️ Security Warning: Never share your private key with anyone. Use a dedicated trading wallet, not your main holdings wallet.

Option A — Create a new wallet (recommended):

1. Open MetaMask → Create New Account
2. Go to Account Details → Export Private Key
3. Copy the hex key (starts with 0x)

Option B — Use an existing wallet:

1. MetaMask → Account Details → Export Private Key
2. Enter your MetaMask password to reveal the key

Option C — Generate via CLI:

# Using cast (foundry)
cast wallet new
# Output: Address: 0x... | Private key: 0x...

Step 2: Fund the Wallet with USDC on Base

Send USDC to your wallet address on Base network:

• USDC contract: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
• Network: Base (chain ID 8453)
• Recommended starting amount: $5–$20 USDC

Check your balance at basescan.org.

Step 3: Configure in NOFX

1. Open NOFX at http://localhost:3000
2. Log in and go to Config tab
3. Click + Add AI Model
4. In Step 0, scroll to Via BlockRun Wallet section
5. Select BlockRun · Base Wallet
6. In Step 1, configure:
   • Wallet Private Key: Your hex private key (0x...)
   • Select Model: Choose from Claude Opus, GPT-5.4, Gemini 3 Pro, Grok 3, DeepSeek R1, or leave as Auto for best available
7. Click Save

How Payment Works

When NOFX sends an AI request:

1. Request goes to https://blockrun.ai/api/v1/chat/completions
2. Server responds with HTTP 402 Payment Required + payment details
3. NOFX signs a ERC-3009 TransferWithAuthorization (EIP-712) with your private key
4. Payment signature is attached and request is retried
5. BlockRun verifies the signature, routes the request to the AI model, and charges USDC

Privacy: Your private key never leaves your NOFX instance. Only the cryptographic signature is sent.

Available Models via BlockRun

Security Best Practices

• ✅ Use a dedicated wallet with only trading budget, not your main wallet
• ✅ Keep only a small USDC balance (top up as needed)
• ✅ Your private key is encrypted at rest in NOFX's database
• ✅ Signatures are spend-limited — each signature authorizes only the exact amount for one request
• ❌ Never export or share your private key outside of NOFX

Troubleshooting

Monitoring Spend

Check your USDC balance and transaction history at:

• Basescan — search your wallet address
• BlockRun dashboard — usage history

← Back to Getting Started