Let your agent pay

Sendpaper accepts Stripe shared payment tokens (SPTs), the way AI agents pay merchants on your behalf. Your agent never sees your card number and neither do we. Each token is capped at one order’s price, works once, and expires.

How it works

The agent creates the order

create_postcard or create_letter returns the order id and its exact price, for example ord_8k2m… for $2.99 (299 cents).

You approve the payment

Your agent asks Stripe Link for a one-time token for that amount. You approve it in Link, on your phone or in the agent.

The agent pays

The agent calls pay_order with the token. We charge it once, the order is marked paid, and it goes to print.

If the agent can’t get a token, it gives you the order’s checkout link instead. That’s a normal Stripe Checkout page, where you can also pay with Link, cards, Apple Pay and more.

For agents: getting a token with Stripe Link

Agents that have Stripe’s Link CLI (as a skill or MCP server) can request a token like this:

npx @stripe/link-cli spend-request create \
  --payment-method-id <the user's Link payment method> \
  --context "Sendpaper postcard ord_8k2m… to Dana Kim" \
  --amount 299 \
  --credential-type shared_payment_token \
  --network-id <Sendpaper's Stripe network ID> \
  --request-approval

--amount is the order’s price.amount_cents.
Sendpaper’s Stripe network ID is returned by the get_pricing tool (payment.stripe_network_id).
--request-approval asks the user to approve before the token is issued.

Then pay:

pay_order(order_id: "ord_8k2m…", shared_payment_token: "spt_…")

Over HTTP

curl https://sendmypaper.com/v1/orders/ord_8k2m.../pay \
  -H "Content-Type: application/json" \
  -d '{ "shared_payment_token": "spt_..." }'

The response is the updated order with "status": "paid".

Errors your agent can fix

Code	Meaning	What to do
`token_amount`	The token’s limit is below the order price	Request a new token for at least the order amount
`token_inactive`	The token was used, revoked or expired	Ask the user to approve a new one
`token_currency`	The token isn’t in USD	Request a USD token
`requires_action`	The bank wants extra verification	Send the user to the checkout link
`not_payable`	The order is already paid or cancelled	Check it with `get_order`

Paying is safe to retry: the same token is never charged twice for the same order.

Safety

You approve every payment. Agents should only call pay_order after you’ve agreed to the purchase and price.
Nothing extra is stored. We keep the Stripe payment reference for refunds, never the card.
Refunds: if we refuse a piece under the content policy, or you cancel before printing, the payment is refunded in full.

Get started

How-to guides

Connect your agent

Reference

Let your agent pay

How it works

For agents: getting a token with Stripe Link

Over HTTP

Errors your agent can fix

Safety

​How it works

​For agents: getting a token with Stripe Link

​Over HTTP

​Errors your agent can fix

​Safety

How it works

For agents: getting a token with Stripe Link

Over HTTP

Errors your agent can fix

Safety