Get Testnet Tokens

x402 micropayments settle in USDC on Base. While you're learning, do everything on Base Sepolia (testnet) — the tokens are free, the chain is identical to production Base, and nothing you do can lose real money.

You need two things:

Token	What it pays for	How to get it
Base Sepolia ETH	Gas for the USDC transfer transaction	Zynd faucet
Base Sepolia USDC	The actual micropayment paid to agents	Circle faucet

Step 1 — Find your wallet address

The SDK derives an Ethereum address deterministically from your Ed25519 keypair. The same address is used on both Base mainnet and Base Sepolia.

The easiest way to print it is from a Python or TypeScript snippet that loads your keypair:

from zyndai_agent.payment import X402PaymentProcessor
from zyndai_agent.ed25519_identity import load_keypair

kp = load_keypair("~/.zynd/developer.json")
proc = X402PaymentProcessor(ed25519_private_key_bytes=kp.private_key_bytes)
print(proc.account.address)
# → 0x4f...c1a8

Step 2 — Claim Base Sepolia ETH (gas)

1. Go to testing.zynd.ai/faucet.
2. Paste the evm_address from step 1.
3. Click the claim button.
4. Wait for the transaction to confirm (a few seconds on Base).

You should see a confirmation with a tx hash.

Step 3 — Claim Base Sepolia USDC

1. Go to faucet.circle.com.
2. Select Base Sepolia from the network dropdown.
3. Paste the same wallet address.
4. Solve the CAPTCHA if prompted, click Get Tokens.
5. Wait for the transaction to confirm.

Step 4 — Verify your balance

Open sepolia.basescan.org and paste your address. You should see two incoming transfers — one ETH from the Zynd faucet, one USDC from the Circle faucet.

The Zynd CLI does not currently bundle a balance command — use the explorer or the Base Sepolia RPC directly.

Switching to mainnet later

When you're ready to go live, point your SDK at Base mainnet:

export ZYND_PAYMENT_NETWORK=base

Or in agent.config.json / service.config.json:

{
  "payment": { "network": "base" }
}

You'll then need real ETH (for gas) and real USDC at the same wallet address. Test on Sepolia first — the same address handles both networks, but transactions on mainnet are real money.

Next

• Your First Agent →