What the $0.99 gets you
One payment, 24 hours of higher limits across the full tool set. The free tier has daily limits; the Day Pass lifts them for a full day. A few tools keep their own limits, and the pass page lists them. When the 24 hours end, nothing renews and nothing charges you again. You decide when the next day starts.
The price, plainly
$0.99. One time. 24 hours. No subscription. Agents pay in USDC on Base; humans pay with PayPal. That is the whole pricing story for the pass.
How an agent buys it itself
This is the part that matters. Your agent does not need your credit card, your approval click, or a checkout page. It pays programmatically through the x402 flow:
- The agent requests the challenge.
GET /api/x402/day-passreturns an HTTP 402 with the payment terms: $0.99 in USDC on Base. - The agent settles it.
POST /api/x402/day-passsubmits the payment onchain. - Access opens. The agent gets 24 hours of higher limits, and the payment itself gets a verifiable execution receipt.
No human in the loop, no card form an agent cannot fill. If you run agents that need paid tools for a day, a sprint, or a demo, this is the cheapest path that requires zero babysitting: fund the agent's wallet once, and it handles the rest.
There is a live test of exactly this flow: a public bounty on WURK pays agents who buy a fresh Day Pass this way, try to break Zambo's receipts and prompt shield, and publish an honest report. Fifteen winner slots. If your agent can pay for itself, it can enter: the bounty page has the terms.
How a human buys it
Open zambo.dev/day-pass and pay $0.99 with Apple Pay, Google Pay, or PayPal. You get a private access key. Paste it wherever your AI app asks for a key, or attach it as the X-Zambo-Key header on the MCP endpoint. The pass is proven by a public receipt, so it works in every AI you use, and the public verification URL never reveals your email, wallet, or key.
Day pass vs subscription: the honest math
Zambo also sells a monthly pass at $29/month. The break-even is simple: $29 divided by $0.99 is about 29 days. If you need full access fewer than 29 days in a month, day passes are cheaper. If you live in the tools every day, the subscription wins. Buy the shape that matches your usage; both are one decision, not a maze of tiers.
For agents specifically, the day pass usually wins: agents work in bursts. A research sprint, a build session, a demo day. Paying $0.99 for the days the agent actually works beats a subscription for days it sits idle.
AI tool access without a subscription and without a per-call meter
Most AI tooling is sold two ways: a monthly subscription, or per-call billing where every request is metered. Both shapes fit agent work badly, because agent work arrives in bursts. The subscription charges for the idle days between bursts. Per-call metering makes the cost of a job unknowable until it finishes, and it still expects an account with a card on file, which the agent doing the work does not hold.
The Day Pass is a third shape: one flat payment of $0.99 for 24 hours of higher limits, no subscription, no auto-renew, and no per-call meter running while the agent works. An agent buys it itself with USDC on Base through the x402 flow above; a human buys the same pass by card through PayPal. When the day ends, access falls back to the free tier until someone buys another day. The payment handshake itself is the subject of the x402 explainer.
Why a day pass exists at all
Subscriptions assume continuous use. Agent work is not continuous; it is spiky. The day pass prices the spike instead of the month. And because every tool call returns a verifiable receipt, you can audit exactly what the $0.99 bought: every call, every result, checkable at zambo.dev/run/<id>. Try getting that receipt from a per-seat SaaS plan.
Start here
Humans: zambo.dev/day-pass. Agents: the x402 challenge at GET /api/x402/day-pass. Either way, $0.99 and 24 hours.
Questions, answered
Is there a day pass for AI tools?
Yes. The Zambo Day Pass costs $0.99 and gives 24 hours of higher limits across the full Zambo tool set. It is a one-time purchase: no subscription, no auto-renew, and when the 24 hours end, access returns to the free tier. Agents buy it themselves with USDC on Base; humans buy it with a card through PayPal at zambo.dev/day-pass.
Can I use an AI API without a monthly subscription?
Yes, two ways. The free tier covers everyday calls with daily limits and needs no subscription at all. When a job needs more, the Day Pass lifts the limits for 24 hours for $0.99, paid once. Neither path creates a subscription: there is nothing to cancel, and a pass that expires simply stops.
What is pay per call API access, and how is a day pass different?
Pay per call means every request is metered and charged individually, usually against an account with a card on file. The Day Pass is the opposite shape: one flat $0.99 payment covers 24 hours of calls at higher limits, with no per-call meter running. Zambo's own x402 challenge says it in the response: not per call, one payment covers 24 hours. Per-call pricing suits steady production traffic. A day pass suits bursty agent work, where the number of calls is not known in advance.
Can I pay one time for AI tool access instead of subscribing?
Yes. The Day Pass is a one-time $0.99 payment for 24 hours. It does not renew, it does not create a subscription, and buying a second day is a second deliberate purchase. Agents pay it in USDC on Base through the x402 challenge; humans pay by card through PayPal. The payment itself returns a verifiable receipt, so what the $0.99 bought stays checkable afterward.
How do I give my AI agent tool access for 24 hours?
Fund the agent's wallet with USDC on Base and let it answer the x402 challenge at the Day Pass endpoint: it signs the $0.99 authorization, settles it, and gets 24 hours of higher limits with no human in the loop. Or buy the pass yourself with PayPal and give the agent the access key. Either way, every call the agent makes during the day returns a verifiable execution receipt, so the day's work is auditable at the end of it.
What does each Zambo pass cost, side by side?
Free tier: everyday calls with daily limits, no account and no payment. Day Pass: $0.99, one time, 24 hours of higher limits. Zambo Pass: $29 per month or $290 per year for higher limits every day. Holder Pass: $19 per month for verified $ZAMBO holders. Every price is listed at zambo.dev/pricing.
What is the $19 holder pass, and how do I get it?
It is the Zambo Pass at $19 per month for verified $ZAMBO holders, instead of the standard $29 per month. The holder tier is listed on the pricing page at zambo.dev/pricing, which shows how holder status is verified.
Do I need an account or an API key to start?
No. Add https://zambo.dev/mcp to your AI and the free tier works with no account, no signup, and no key. If you buy a Day Pass as a human, you get a private access key with it; that key is the pass, not an account.
Which AIs does Zambo work with?
ChatGPT, Claude, Grok, Gemini, Cursor, VS Code, Windsurf, and any other MCP-capable client. Setup for each one is the same one paste of the endpoint, https://zambo.dev/mcp. The same pass works in every AI you use, because the pass is proven by a public receipt rather than tied to one app.
Does my agent need my approval to pay for the Day Pass?
Not from Zambo. An agent with a funded wallet may pay the $0.99 Day Pass itself through the x402 challenge, with no human approval required by Zambo. Your own wallet or spending policy still applies, and the payment returns a verifiable receipt so you can check what was bought.
What if my agent has no wallet or no money?
Then it cannot settle the x402 challenge, and nothing is charged. Buy the pass yourself at zambo.dev/day-pass with a card through PayPal and give the agent the access key, or keep working on the free tier, which needs no payment at all.
What does a verifiable receipt prove, and what does it not prove?
It proves the saved result of a call has not changed since it was saved: the tool, the time, and the output bytes are checkable by anyone. It does not prove the answer was correct. Zambo receipts follow AER-1, an open format published as IETF Internet-Draft draft-zambo-aer1-23.
What happens if a tool fails in the middle of a job?
The failed call still returns a verifiable receipt, and the saved output is the error itself, so you can see exactly which step failed and why. There is no per-call meter, so a failure adds no extra charge, and the rest of the day's work stays receipted as usual.
How do I know my Day Pass is active, and where do I see what my AIs did?
Agents check the day_pass_status tool on the MCP endpoint; it reports whether the pass is active and when it expires. Every call your AIs make returns a receipt you can open at zambo.dev/run/
How do I hand finished work to a client, and where do I get help?
Use Handover: one link shows your client every step as a verifiable receipt, checked in their browser, and they Accept or Flag it in one tap. The proof of delivery page on this hub walks through it. For billing help, contact brennanzambo@zambo.dev; the refund policy is stated on the Day Pass page at zambo.dev/day-pass.