💳 How to Pay for Agent Calls

There is no deposit and no balance to top up. Your agent holds its own USDC on Base and pays per call over x402.

⚠️ Do not send USDC to the minia2a platform wallet expecting a balance.

minia2a does not operate a top-up rail. The platform wallet address appears in a 402 challenge as payTo and is paid as part of an x402 payment for a specific call — a plain transfer to it outside that flow credits nothing.

🧠 The Payment Model

No prepaid balance, no monthly cap, no auto-charge. You start with free trial calls; after that your agent pays the listed price per call, in USDC on Base, at the moment it calls. The platform never holds your key and never holds your money between calls.

You do: Put USDC in your agent's own wallet (or let it pay from a wallet you control)
Your agent does: Discover APIs → handle the 402 → pay per call → get the result
You never do: Approve each transaction, manage an account, or leave funds parked with a third party

📋 Overview

1Sign your wallet — 5 free trial calls, no registration, no deposit (1 min)

2Fund your own agent wallet with USDC on Base — see the three methods below (5 min)

3Let the agent pay per call — it handles the 402 challenge and settles each call (automatic)

🎁 Step 0: Your 5 Free Trial Calls

Sign a message with your wallet and call any service. No registration, no card, no USDC spent.

MSG="minia2a trial:$WALLET:x402-time:$TS"   # sign with EIP-191 (personal_sign)
curl "https://minia2a.uk/x402/time?wallet=$WALLET" \
  -H "X-Wallet-Signature: $SIG" -H "X-Trial-Timestamp: $TS"
# -> 200, x-trial-mode: wallet, x-trial-remaining: 4

Trials are free and shared across the whole catalog. Full recipe in AGENTS.md.

🔵 Method 1: Coinbase (Easiest)

If you have a Coinbase account, this takes 3 minutes. The destination is your agent's own wallet — not a minia2a address.

EASIEST

Buy USDC on Coinbase, send it to your agent's wallet on Base

aOpen Coinbase → Buy USDC with card/bank transfer

bGo to Send → select USDC → choose Base network

cDestination: your agent's own wallet address (the wallet you sign calls with)

dSend. Wait ~30 seconds for confirmation.

🌉 Method 2: Bridge from Another Chain

Already have USDC on Ethereum, Arbitrum, Optimism, or Polygon? Bridge it to Base first, then send to your agent's wallet.

NO COINBASE NEEDED

Use a Bridge

aGo to bridge.base.org (official Base bridge) or jumper.exchange

bConnect your wallet → select source chain → destination: Base → token: USDC

cEnter amount → confirm → wait ~2-5 minutes

⚠️ Bridging costs gas on the source chain. Ethereum mainnet gas can be $5-15. L2s (Arbitrum, Optimism) are cheaper.

🦄 Method 3: Swap on Base (For Crypto Natives)

Already have ETH or another token on Base? Swap directly in the wallet your agent pays from.

ADVANCED

Swap ETH → USDC on Base DEX

aGo to Uniswap or Aerodrome (Base native)

bConnect wallet → switch to Base network → swap ETH for USDC

🔁 Where the USDC Actually Goes

Nowhere in advance. Each paid call settles to the service's own payTo address, quoted in the 402 challenge for that call. There is no intermediate balance:

curl "https://minia2a.uk/x402/time?probe=1"   # 402 + accepts[] with amount + payTo
# then retry the call with the payment proof header the challenge asks for

Full payment flow, headers and receipts:

minia2a.uk/docs#pay

Read the payment docs →

❓ FAQ

Can I prepay a balance so my agent doesn't have to pay per call? No — there is no top-up rail. Wallets that held a balance before 2026-09-06 keep it (converted to microUSDC), and it stays spendable on minia2a platform endpoints, but it is not withdrawable and cannot be added to.

Do I need an account or API key? No. Your wallet address is your identity. You sign a message locally; the platform never sees your private key.

Why Base? Why not Ethereum mainnet? Base costs ~$0.01 in gas vs $5-50 on Ethereum. Since minia2a payments are micropayments ($0.005/call), using Base keeps costs near zero.

What if I send USDC on the wrong network? Always double-check you're on Base. Funds sent on other networks to a wallet you do not control cannot be recovered by us.

How much should I put in my agent's wallet? Whatever you're comfortable letting it spend — the wallet is yours, there is no minimum. Most calls cost $0.005–$0.50, so $5–$10 covers thousands of calls.

What are the fees? minia2a charges 5% on seller earnings (0% through 2026). As a buyer, you pay the listed price per call — no hidden fees. Base network gas is ~$0.01 per transfer.

📚 Related

minia2a.uk — M2M micropayments for AI agents. Powered by x402 protocol + USDC on Base.