Quickstart

Prerequisites

• A Base wallet funded with USDC (or a developer API key)
• Node.js 18+

Install dependencies

bash
npm install @coinbase/agentkit viem

Make your first query

typescript
import { AgentKit } from '@coinbase/agentkit'
import { privateKeyToAccount } from 'viem/accounts'

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`)
const agentKit = await AgentKit.from({ account })

// The x402 client handles the 402 → sign → retry cycle automatically
const result = await agentKit.fetch('https://apitoken.agentchaintools.xyz/graphql', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    query: `{
      newTokens(maxAgeSeconds: 3600, minLiquidityUsd: 10000, limit: 5) {
        tokens {
          address
          symbol
          price { usd change24h }
          risk { score isHoneypot }
        }
      }
    }`
  })
})

const data = await result.json()
console.log(data.data.newTokens.tokens)

The first request returns a 402 with payment requirements. AgentKit signs the Permit2 authorization and retries automatically. You only pay when you receive data.

Using a developer API key (no wallet needed)

For testing during development, you can use an API key instead of x402 payments:

typescript
const result = await fetch('https://apitoken.agentchaintools.xyz/graphql', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'sk_test_your_key_here',
  },
  body: JSON.stringify({
    query: `{
      newTokens(limit: 5) {
        tokens { symbol price { usd } }
      }
    }`
  })
})

API keys have a credit balance that decreases with each query based on complexity. Switch to x402 for production.

Checking query cost before paying

Send any query without a payment header or API key. The 402 response body tells you the exact cost:

json
{
  "error": "Payment required",
  "details": {
    "amount": "0.000360",
    "currency": "USDC",
    "queryCostUnits": 18,
    "costPerUnit": 0.00002
  }
}

Your agent can read this and decide whether to proceed.

Get your wallet funded

You can acquire USDC on Base via:

• Coinbase — direct withdrawal to Base
• bridge.base.org — bridge from Ethereum mainnet
• Uniswap on Base — swap ETH → USDC

Try it without paying

Use the Playground to test queries for free. The playground uses a server-side bypass so you can explore the schema and data without any payment.