coinrailz-agentkit

Coinbase AgentKit action provider for the CoinRailz USDC Yield Vault on Base.

5 actions:

• coinrailz_yield_deposit — approve + deposit USDC (2 txs, works with any wallet)
• coinrailz_yield_deposit_permit — EIP-2612 permit deposit (1 tx, requires signTypedData)
• coinrailz_yield_redeem — redeem crUSDC shares for USDC (1 tx, 0% exit fee)
• coinrailz_yield_check_position — live on-chain position query
• coinrailz_yield_get_rates — live APY across Aave v3, Compound v3, Morpho Blue

Vault: 0x86e2508ca0de34530dc847645f60f0d46d95176a (Base mainnet, ERC-4626)
Auto-routes to highest-yield protocol. 0.5% entry fee, 15% performance fee on yield, 0% exit.

Install

npm install coinrailz-agentkit

Usage with Coinbase AgentKit

import { AgentKit } from '@coinbase/agentkit'
import { CoinRailzYieldActionProvider } from 'coinrailz-agentkit'

const agentKit = await AgentKit.from({
  walletProvider,
  actionProviders: [
    new CoinRailzYieldActionProvider(),
  ],
})

// Your agent now understands:
// "Deposit $100 USDC to earn yield"
// "Check my current yield position"
// "What APY am I earning?"
// "Withdraw my USDC"
// "Deposit $50 USDC in a single transaction"  ← uses permit

Usage standalone (no AgentKit)

import { CoinRailzYieldActionProvider } from 'coinrailz-agentkit'

const provider = new CoinRailzYieldActionProvider()

// Deposit $100 USDC
const result = await provider.deposit(walletProvider, { amount_usd: 100 })
console.log(result) // "✅ Deposited $100 USDC..."

// 1-tx permit deposit (requires wallet.signTypedData)
const result2 = await provider.depositPermit(walletProvider, { amount_usd: 100 })

// Check position
const pos = await provider.checkPosition(walletProvider, {})

// Withdraw all
const redeem = await provider.redeem(walletProvider, {})

Permit vs Standard Deposit

| Mode | Transactions | Requires | |------|-------------|----------| | coinrailz_yield_deposit | 2 (approve + deposit) | Any EVM wallet | | coinrailz_yield_deposit_permit | 1 (permit + deposit) | wallet.signTypedData |

The permit flow uses EIP-2612 (supported by USDC on Base) and routes through the PermitAndDeposit helper contract.

Wallet Provider Interface

Your wallet must implement:

interface EvmWalletProvider {
  getAddress(): string
  sendTransaction(tx: { to: `0x${string}`; data: `0x${string}` }): Promise<`0x${string}`>
  waitForTransactionReceipt(hash: `0x${string}`): Promise<{ status: string }>
  readContract(params: { address: `0x${string}`; abi: ...; functionName: string; args?: ... }): Promise<unknown>
  signTypedData?(params: { domain; types; primaryType; message }): Promise<`0x${string}`>  // optional, for permit
}

Coinbase AgentKit's EvmWalletProvider, CDP SDK wallets, viem WalletClient, and ethers Signer all satisfy this interface with minor adapters.

Links

• Vault on Basescan
• PermitAndDeposit on Basescan
• API manifest
• Yield portal