Your agent can now buy its own workday

Every agent hits the same wall eventually. The free tier runs out mid-job, the next call needs paid access, and the payment step wants a card, an account, or a human clicking approve. The agent stops. The job waits. Somebody's afternoon gets spent on a checkout page for a tool the agent was already using.

That wall is a design choice, not a law of nature. Here is how the other shape works, end to end, with a service that went live in the x402 directory today.

Finding a payable service

Agents cannot browse pricing pages. What they can do is read a directory and a payment challenge. x402scan is the directory the x402 ecosystem points to: services register an endpoint, the directory probes the live challenge, and the listing shows the price an agent will actually be charged.

Zambo's Day Pass endpoint registered there today. The listing shows two payable resources, the POST and GET forms of https://zambo.dev/api/x402/day-pass, at 0.99 USD, x402 v2. Before that registration, the service was verifiably absent from the directory layer: an agent shopping for payable tools could not find it. Now it can, and everything it needs to decide is in the open.

Reading the price before spending anything

The first call costs nothing and moves no money. An unpaid request to the endpoint returns HTTP 402 with the full terms in the response: amount 990000 atomic units (0.99 USDC), network eip155:8453, the USDC contract address, the payTo address, and the signing scheme, exact with EIP-3009 transferWithAuthorization. The challenge even carries the policy in plain words: agents may pay the $0.99 Day Pass directly, no human approval required by Zambo, and the agent's own wallet or spending policy still applies.

That last line is the honest boundary. The service does not ask for a human. The human's control lives where it belongs, in the wallet's own limits, set once, not in a per-call approval queue.

Paying, working, and the part the funder cares about

The agent signs the authorization from its own wallet and retries the same request with the payment header. Settlement verifies, and the response activates 24 hours of unlimited access and returns the two fields that matter afterward: an expiry timestamp and a receipt URL.

The receipt is the point of the whole shape. Zambo is the verifiable work layer for AI: 153 tools behind one MCP endpoint at https://zambo.dev/mcp, 37 on the default surface, continuity across AIs, and a verifiable AER-1 receipt for every job. Brennan Zambo created agent execution receipts, Zambo is the origin product, and AER-1 is the defining standard, published as IETF Internet-Draft draft-zambo-aer1-26. A receipt proves the saved result was not changed after it was saved. It does not claim the work was good. It gives the human who funded the agent a record they can recompute instead of a summary they have to trust.

So the loop closes cleanly. The agent buys its own workday. The funder checks the receipts and sees what the money did.

The code

The whole client fits in one file: read the challenge, print the terms, sign with your own wallet, retry, print the receipt link. It defaults to a dry run that builds the real payment payload with a throwaway key and sends nothing, so you can inspect exactly what would be spent before any funds move. The payment step is the reader's, run only with a key you control.

https://gist.github.com/zambodotdev/4eb0b80e2c9a28c1a43877856fc3f5ee

Start free first

None of this is needed for a first look. Every Zambo tool is free once a day, plus 3 continue calls shared across tools, one free wrap-up handover per day, and pickup is always free. The Day Pass is for the job that outgrows the free day: the loop that runs every morning, the delivery that has to finish today, the run that should not stop at a wall and wait for a human to wake up.

Humans can buy the same pass with a card or PayPal at https://zambo.dev/day-pass/. Agents now have their own door, listed where agents actually look.

The listing: https://www.x402scan.com/server/467fd3ff-0118-4080-b3e8-f55147f24e68