What is the Zambo x402 Day Pass?
The Zambo Day Pass costs $0.99 USDC on Base via x402 v2. Review the receipt and actual deliverable before accepting a handover.
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| Price | 0.99 USDC |
|---|---|
| Network | Base mainnet (eip155:8453) |
| Scheme | x402 v2 "exact", EIP-3009 TransferWithAuthorization |
| Window | 24 hours (86400 s) |
| Returns | access_key, expires_at, receipt_url, settlement tx |
| Gas | payer needs no ETH (relayer submits) |
| Failure | 402 refusal receipt with policy_reason |
Pay and activate
Request the challenge at https://zambo.dev/api/x402/day-pass, sign the authorization after approval, and POST the Base64 JSON envelope in X-Payment. The v2 envelope is {x402Version:2,accepted:{scheme,network,asset,amount,payTo,maxTimeoutSeconds,extra},payload:{signature,authorization}}. Copy accepted from the live challenge's accepts[0]; do not put scheme and network at the top level for v2.
Use the pass with your bot
Connect to https://zambo.dev/mcp. /api/mcp is the backwards-compatible alias for the same connection. Include _zambo_key in any tool's arguments, or send X-Zambo-Key. To avoid copying a key, call day_pass_activate with the bot's original _session_id. After activation reports session_bound:true, use that same job ID with every tool. day_pass_status checks activation without spending quota.
Refused payments and proof
A refused invalid signature can be retried with a newly recorded authorization. Never reuse a consumed nonce or prior signature. If the authorization expired, request a fresh challenge. A refusal is not a charge. Verify the returned run ID or x402 spend receipt ID at /api/v2/receipt/{id}/verify. Legacy payment receipts can prove output integrity but do not authenticate unbound provenance labels.
Our own test purchase: receipt 768e9f76. Humans: buy a Day Pass by the one-time Day Pass checkout. How an AI agent pays for tools.
Frequently asked questions
Is the Zambo Day Pass per-call?
No. One $0.99 USDC payment on Base via x402 covers 24 hours of Zambo connection access.
How does an AI agent buy the Zambo Day Pass?
For developers
GET or POST https://zambo.dev/api/x402/day-pass to receive the 402 challenge, sign the EIP-3009 USDC authorization, and retry the POST with the X-Payment header. Or call the MCP tool day_pass_activate. The response returns access_key and expires_at.
How does the agent use the Day Pass?
For developers
Connect to https://zambo.dev/mcp; /api/mcp is its backwards-compatible alias. Send _zambo_key in any tool's arguments or the X-Zambo-Key header. If the pass is bound to your job, use the same _session_id instead. Check activation with day_pass_status.
Can a refused signature be resubmitted?
A refused invalid signature is retryable with a newly recorded authorization. Do not reuse a prior signature or consumed nonce. Request a fresh challenge if the authorization expired.
Does the paying wallet need ETH for gas?
No. The recorded EIP-3009 authorization is submitted verifiable by a relayer. The wallet needs at least 0.99 USDC on Base.
Is there a receipt for the payment?
Yes. A successful payment returns a run receipt, an x402 spend receipt with an audit URL, and the settlement transaction hash. A failed payment returns a refusal receipt.