$0to participate
Enrollment, discovery and agent tools cost nothing, with no card required.
- Free enrollment for consumers, builders and providers
- Live discovery and routing tools, no subscription
- Expressing a need is always free
Pricing
Simple pricing.
Pay per result.
Joining Stackbroker is free — for consumers, their agents, and service businesses — and no wallet is required to join. When paid bookings launch, your agent will pay a $0.50 fee for a successfully confirmed booking: per transaction, from funds you control, under caps you set. No subscriptions. No card on file. Providers never pay us anything.
What things cost.
$0.50per booking
Paid by your agent, in USDC on Base, only when a booking is successfully confirmed — within the all-in cap you authorize.
- Failed match: $0
- Provider or system failure: our fee is reversed
- You explicitly authorize the fee in advance, per booking
$0to participate
Being listed, matched and ranked never costs a provider anything.
- No provider subscription or listing fee
- No paid placement or sponsored ranking
- Consumers pay the fee, never you
Pricing is subject to change. Consumer booking billing is not active yet. Until paid bookings launch, no consumer booking fees are charged.
How agents pay.
We will charge personal agents through x402 or another supported micropayment solution. Here is the planned payment design for x402 using USDC on Base. It is not active checkout today.
What’s live today: free pilot enrollment with saved-request receipts, plus agent discovery and routing tools with audit receipts. Enrollment does not create a booking.
Planned, when paid bookings go live: confirmed consumer bookings and the payment flow below. No consumer booking fees are collected today. Any alternative payment method will be disclosed before you authorize a charge.
- 01
You approve the total
Before a booking commitment, you see the provider’s service price, our $0.50 fee, and cancellation terms. Each fee is explicitly authorized in advance, per booking. Your all-in cap includes the service price and our fee: together they can never exceed the total you approved. For example, a $40 service plus our fee requires a $40.50 cap. This payment flow covers our fee; payment to the provider is disclosed separately.
- 02
Stackbroker quotes the fee to your agent
The booking request receives HTTP 402 Payment Required with machine-readable requirements: exactly 0.50 USDC, the Base network, the USDC token and Stackbroker’s receiving address. Your agent checks these details against your approval and remaining budget before signing.
- 03
Your agent authorizes one payment
Using a compatible funded wallet, your agent signs an EIP-3009 transferWithAuthorization for that exact amount and recipient, with a unique nonce and an expiry. It retries the same booking request with that authorization. Signing is permission to transfer; it is not yet a settled charge. No seed phrase or private key is sent to Stackbroker.
- 04
Verify, confirm, then settle
A payment facilitator verifies the authorization. Stackbroker must obtain the provider’s booking confirmation before requesting settlement of our fee. The facilitator then submits the USDC transfer on Base and pays the network gas for that transfer; it cannot change the signed amount or recipient. Funding or withdrawing from your wallet may have separate wallet or exchange costs.
- 05
You get a booking and payment receipt
Once both booking confirmation and settlement succeed, your agent receives the booking reference, the 0.50 USDC charge and the onchain transaction hash. A payment receipt proves payment, not that the service was delivered. If confirmation or settlement is uncertain, the request stays pending for reconciliation; retrying the same booking must return its existing status, not create another charge.
- 06
Failed matches cost nothing
No confirmed match means no fee settlement. If a provider or system failure happens after payment, our fee is reversed through a separate refund transfer with its own receipt; the original blockchain transaction is not erased. Provider cancellation charges, if any, follow the terms you approved. Your agent and wallet integration must enforce spending caps and stop when authorization is missing—x402 alone does not enforce your overall budget.
Technical details for agent builders
The planned HTTP integration uses x402 v2: PAYMENT-REQUIRED on the 402 response, PAYMENT-SIGNATURE on the retried request, and PAYMENT-RESPONSE after settlement. The exact EVM scheme uses Base mainnet (eip155:8453); 0.50 USDC is 500000 atomic units. Clients must validate the token, network, recipient, amount and expiry, and retain the same booking idempotency key on retries. A valid wallet signature is not a substitute for authenticated booking ownership. No production paid-booking endpoint or merchant receiving address is published yet; do not send funds manually.
Wallets: optional until your agent pays.
No wallet is needed to join the pilot, express a need, or be matched with a provider. A wallet only matters once paid bookings go live and your agent begins paying the $0.50 fee — and it stays yours: you fund it, you cap it, and you can stop any time.
When that day comes, agents pay from a wallet you control, funded with USDC on Base. Choose Base when transferring USDC; a balance on another network is not the same balance. Review any funding fees before transferring.
For consumers
Fund your agent (later, if you want paid bookings)
Use Coinbase’s consumer wallet onboarding to create a Base-compatible wallet. When paid bookings switch on, create one, add USDC on the Base network, and fund your agent’s spending wallet within the caps you choose.
For agent builders
Wire up x402
Coinbase Agentic Wallet provides a Coinbase-managed wallet your agent can use through CLI or MCP, with funding and spending-limit controls. Builders can also integrate a compatible signer using the x402 buyer SDK. A consumer wallet and an agent wallet may have different custody and permission models.
USDC on Base is the funding asset for agent payments. Only fund a wallet you own or have authorized; Stackbroker never asks for your keys or seed phrase.