What is Tab
One payment rail, two kinds of payers — humans pay with an email, AI agents pay x402 under a hard cap.
Tab is a payments product with one rail and two payers:
- Humans check out with an email. No wallet extension, no seed phrase — a one-time code creates a wallet behind the scenes and the payment settles in USDC.
- AI agents pay x402
402 Payment Requiredresponses by themselves, through an MCP proxy that enforces a spending cap outside the model. The agent never holds a key.
Both payers settle on the same rail and leave the same evidence: a receipt with an amount, a network, and a transaction hash.
The three surfaces
| Surface | Who it's for | What it does |
|---|---|---|
<PayButton> | Your customers | Embedded checkout: email → code → pay |
| Merchant dashboard | You | Keys, webhooks, transactions, go-live |
| Agent dashboard | Agent owners | Provision, cap, fund, connect, revoke |
Testnet is honest
Tab's Testnet runs on Base Sepolia with real on-chain money movement — funding is a real faucet transfer, balances are real on-chain reads, and settlement is a real USDC transfer verified via RPC with the transaction hash on the receipt. Everything labeled "Sandbox funds — no real value" is exactly that. Live (Mainnet) execution is gated until the production money-mover spike is verified; Testnet is fully functional end to end.
Where to start
- Want to feel it first? try.runtab.xyz — a live
checkout anyone can pay with just an email (bring your own
pk_testto make it your storefront). - Selling something? Start with the Quickstart.
- Wiring an agent? Start with Agents & x402.
- Want free test funds? See Test funds.