Built on PayPal · x402-compatible

Let AI agents pay for APIs by the cent, settled on PayPal.

Each call goes on a tab. PayPal charges the buyer once for hundreds of calls and pays the seller out.

Connect your PayPal wallet Sell your API
Claude Code · this weektab
  • POST /v1/summarize$0.01
  • POST /v1/summarize$0.01
  • POST /v1/summarize$0.01
  • ⋯ 297 more calls
One PayPal charge$3.00
PayPal fee$0.59
300 separate charges$147.10 in fees
Paid out to the seller$2.35

Why a tab?

A PayPal charge costs at least $0.49, which is 49 times a one-cent API call. Drag the slider to compare.

Charge every call

How checkout works on the web today

  1. Agent call
  2. Checkouta person, each time
  3. PayPal chargeevery call

1 dot = 1 call

PayPal charges300
PayPal fees$147.10

The fees are 49× what the calls cost.

Tab402

Calls go on a tab, PayPal settles it

  1. Agent call
  2. Signed voucher≈ 7 ms
  3. Tabup to $10
  4. PayPal chargeonce per tab

1 dot = 1 call

PayPal charges1
PayPal fees$0.59

The buyer approves once, when they save their wallet.

PayPal's US rate of $0.49 + 3.49% per charge. Tab402 charges a tab when it reaches $10 or after 24 hours; this assumes the calls land within a day.

How it works

Each arrow is labeled with the PayPal API it uses. PayPal only moves money in step 3.

1 · Once

The buyer saves a PayPal wallet. Nothing is charged yet.
BuyerTaps Connect PayPal
JS SDK v6 save flowpopup · redirect on mobile
PayPalPayPal approvalBuyer logs in and approves
Setup → payment tokenVault API v3
Tab402 mandateEncrypted vault token plus a budget

2 · Every call

A cent at a time, with no PayPal fee per call.
AI agentClaude over MCP, or any HTTP client
HTTP 402 → signed voucherx402 tab scheme
Seller's APIMiddleware quotes a price per route
verify · settle≈ 7 ms gate overhead
Tab402 facilitatorChecks the budget and adds the call to the tab

3 · Settlement

Hundreds of calls settle as one PayPal charge.
Buyer's tabDue at $10 or after 24 h
One merchant-initiated captureOrders API v2 + vault_id
PayPalTab402 PayPal accountMerchant of record for the charge
Weekly batchPayouts API
PayPalSeller's PayPalWebhooks confirm each payout

PayPal products in Tab402

Every product plugs into the same funding or payout adapter. Hover or tap one for details.

1

Buyer funds

How a buyer pays in
Live in Tab402Save payment method (vault without purchase)

Buyers save their PayPal wallet without buying anything. It opens a popup on desktop and a redirect on phones, and the server finishes the flow if the browser changes.

Live in Tab402/v3/vault/setup-tokens → payment-tokens

PayPal returns a merchant vault token. Tab402 encrypts it on the server, and no browser or agent ever sees it.

Tested in sandbox/v2/invoicing/invoices

Enterprise buyers can get the month's tab as a PayPal invoice with payment terms instead of saving a wallet.

Plannedtransaction.sale · paymentMethodToken

Agents could pay with saved cards, charged merchant-initiated. Fraud Protection Advanced scores would feed the spend guard.

PlannedVaulted via the PayPal SDK or Braintree

US buyers could fund their personal agents with Venmo, through the same funding adapter as PayPal.

2

Tab402 charges

How a tab is settled
Live in Tab402/v2/checkout/orders + vault_id

Tab402 captures a whole tab or top-up in one merchant-initiated call, sending PayPal's device-risk header.

PlannedPlans + overage on the tab

A seller keeps a subscription for the base fee. Tab402 meters usage above the allowance and charges it each billing cycle.

PlannedPayPal crypto settlement

Tabs could settle in PayPal's stablecoin, for sellers who already take USDC over x402.

3

Seller is paid

How money goes out
Live in Tab402/v1/payments/payouts

One batch a week to each seller's PayPal account. PayPal's fee is recorded per item, and items that hit INSUFFICIENT_FUNDS are retried.

PlannedREST v4 payouts

Sellers in countries PayPal Payouts doesn't reach could be paid straight to a local bank account, with no PayPal account.

4

Reconcile

Books and agent tools
Live in Tab402verify-webhook-signature

Tab402 checks the signature on each PAYMENT.CAPTURE.* and PAYOUTS-ITEM.* event, drops duplicates and updates the ledger.

PlannedPayPal MCP server

PayPal's MCP tools handle shopping and invoices; Tab402's MCP server handles pay-per-call APIs. One agent can use both.

Other features

Spend guard

Budgets and caps checked on every call. Claude Haiku reviews borderline buys.

Passkey approval

Purchases over your limit wait for Face ID or Touch ID.

Push and email alerts

Approval requests reach your phone or inbox. Decline right from the email.

Works in Claude

Add one MCP URL and sign in with OAuth.

OpenAPI onboarding

Paste a spec and Claude suggests a price per route.

Revenue analytics

Ask the dashboard why revenue dropped on Tuesday.

Your agents already speak 402. Let them pay with PayPal.

Runs on the PayPal sandbox. Use a sandbox account to try it.

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