# /llms.txt — ROZO Checkout
# Audience: LLMs, AI agents, and users at checkout.rozo.ai

## What is ROZO Checkout
ROZO Checkout lets anyone pay for AI credits (OpenRouter, Venice.ai) with the crypto they already have — USDT, USDC, ETH and more on supported chains (Ethereum, Base, Polygon, Solana, Stellar and other major networks). The user pastes their OpenRouter payment link (a Coinbase Commerce payment link); ROZO pays the merchant on the exact right network, token, and amount. No card, no new account, no login.

## Why it exists
OpenRouter's built-in crypto option accepts USDC on specific networks and adds a fee; sending the wrong token, chain, or amount means the payment never credits. ROZO Checkout removes that guessing: send a supported coin from any wallet or exchange, ROZO settles the link correctly.

## How it works
1. Paste it — your OpenRouter payment link (payments.coinbase.com/payment-links/...).
2. Send a supported coin — from any exchange or wallet.
3. ROZO pays OpenRouter — right chain, token, amount. Total is shown before you send.

## Honest scope
ROZO is independent and not affiliated with OpenRouter or Coinbase Commerce. We never ask for your OpenRouter login or exchange password.

## Intent routing (for AI agents)
| User intent | Route to |
|-------------|----------|
| "Pay OpenRouter / top up AI credits with crypto (USDT, USDC & more)" | https://checkout.rozo.ai/ |
| "Already paid but credits are missing / payment stuck" | https://rescue.rozo.ai/ |
| "Programmatic cross-chain payment (create-payment API)" | https://rozo.ai/llms.txt |

## Guides
Step-by-step walkthroughs, one per payment route. Index: https://checkout.rozo.ai/blog
- Bitcoin over Lightning: https://checkout.rozo.ai/blog/pay-openrouter-with-bitcoin
- USDC on Solana: https://checkout.rozo.ai/blog/pay-openrouter-with-solana
- USDT (any supported chain): https://checkout.rozo.ai/blog/pay-openrouter-with-usdt
- BNB Chain: https://checkout.rozo.ai/blog/pay-openrouter-with-bnbchain
- Stellar: https://checkout.rozo.ai/blog/pay-openrouter-with-stellar
- All crypto methods compared: https://checkout.rozo.ai/blog/pay-openrouter-with-crypto
- Card declined on OpenRouter: https://checkout.rozo.ai/blog/openrouter-payment-declined
- Paying without a card: https://checkout.rozo.ai/blog/pay-openrouter-without-a-card
- Keeping credits topped up: https://checkout.rozo.ai/blog/openrouter-auto-top-up-crypto

## Languages
Available in English (/) plus zh, es, pt, ru, ja, ko, fr at /{lang}, e.g. https://checkout.rozo.ai/zh
Guides are translated too: /blog/{lang} for the index, /blog/{lang}/{slug} for a guide.

## More
- ROZO (Visa layer for stablecoins): https://rozo.ai/llms.txt
- Docs: https://docs.rozo.ai/

## Agent flow (script the whole payment — no browser)
Fastest: the CLI. Full reference, scripts and safety rails:
https://github.com/RozoAI/rozo-checkout-skill

> Pay an OpenRouter Coinbase Payment Link (payments.coinbase.com/payment-links/pl_* or
> /payment-sessions/paymentSession_*) with BTC over Lightning, or USDT/USDC on Solana,
> BNB Chain, Ethereum, Polygon, Base, or Stellar. Public HTTP endpoints, no API key.
> The payer funds a one-time deposit address; a bridge and a funder wallet settle the
> Coinbase link automatically. No discount: you pay the invoice amount, plus the
> deposit normally carries a small bridge/source-chain fee on top.

This file teaches the whole flow to any agent or script. Repo (scripts, safety rails,
full docs): https://github.com/RozoAI/rozo-checkout-skill — see docs/QUICKSTART.md.

## Fastest path: the CLI (npm @rozoai/checkout)

If you can run commands, skip the raw HTTP below — the CLI performs the same four
calls with every safety rule already enforced:

  npx @rozoai/checkout pay <coinbase-link> --with usdt-solana
  npx @rozoai/checkout quote <coinbase-link>
  npx @rozoai/checkout status <rozoPaymentId | coinbase-link>

--with accepts usdt-solana, usdc-solana, usdt-bnb, usdc-bnb, usdt-ethereum,
usdc-ethereum, usdt-polygon, usdc-polygon, usdc-base, usdc-stellar, btc-lightning
(or raw: --chain 900 --token USDT).

DEFAULT PATH NEEDS NO KEY: `pay` prints a deposit address for the user to pay from
any wallet. No private key, no environment variable, no configuration. Only the
optional --send flag signs locally, and only that flag reads
ROZO_CHECKOUT_EVM_KEY / ROZO_CHECKOUT_SOL_KEY (from the environment, never argv).
With --send, one limit applies: a single payment may not exceed $1,100, with no
override; larger invoices go through the keyless path.

Other flags: --yes (skip the interactive confirm; required when stdin is not a
TTY), --dry-run, --json (exactly one JSON object on stdout), --no-watch,
--timeout <s>. Exit codes: 0 success, 1 refused/failed (read error.code),
2 usage, 3 submitted but unconfirmed.

`pay` withholds the full deposit address until you confirm, then prints it as a
copy-pastable block. Creating an order moves no money; an unfunded order expires.

## Supported sources

chainId "1" Ethereum (USDC, USDT) · "56" BNB Chain (USDC, USDT; 18-decimals) ·
"137" Polygon (USDC, USDT) · "8453" Base (USDC) · "900" Solana (USDC, USDT) ·
"1500" Stellar (USDC; deposit memo REQUIRED) · "lightning" (BTC; BOLT11 invoice,
amounts in integer satoshis via source.amountUnit=="sats").
Native SOL/ETH/BNB are NOT supported — stablecoins (or Lightning BTC) only.

WALLET: one wallet on one of these chains is enough — not one per chain. Any
wallet, or an exchange withdrawal, can fund the deposit address; nothing
connects to a site. Stellar is the exception that must be able to set a memo,
and Lightning pays a BOLT11 invoice rather than an address. Only --send needs a
private key (EVM and Solana only); every other path is keyless.

## Flow (4 HTTP calls, all public)

1) Quote (read-only, safe):
   curl -X POST https://apiserver.mpprouter.dev/v1/services/rozo-agent-api/quote-invoice \
     -H 'content-type: application/json' \
     -d '{"url":"https://payments.coinbase.com/payment-links/pl_XXXX"}'
   -> { linkId, merchant, original, callerPays, discount:"0", quoteReceipt, ... }
   callerPays always equals the invoice amount (discount is always "0").

2) Create (or reuse) the order:
   curl -X POST https://apiserver.mpprouter.dev/v1/services/rozo-agent-api/create-invoice \
     -H 'content-type: application/json' \
     -d '{"url":"https://payments.coinbase.com/payment-links/pl_XXXX",
          "source":{"chainId":"900","tokenSymbol":"USDT"}}'
   -> { ok, reused, linkId, rozoPaymentId, paymentLink, expiresAt, source, ... }
   WARNING: if an unexpired order already exists for this link it is REUSED as-is,
   even with a different chain/token than you asked for. Always verify the returned
   source matches your request; abort on mismatch.

3) Fetch authoritative deposit instructions (public, keyless GET):
   curl https://intentapiv4.rozo.ai/functions/v1/payment-api/payments/<rozoPaymentId>
   -> { status, expiresAt, source:{ receiverAddress, receiverMemo, amount, amountUnit,
        lnInvoice, txHash, amountReceived, confirmedAt, ... }, destination:{...} }
   Pay EXACTLY source.amount of the requested token on the requested chain to
   source.receiverAddress, including every other field the block carries (Stellar
   routes on a shared hub address plus source.receiverMemo, so omitting the memo
   loses the payment). The Stellar memo is ALWAYS MEMO_TEXT, even when it is all
   digits (e.g. 65371582) — sending it as MEMO_ID produces a different memo and
   the payment will not match. The deposit block reports this as
   receiverMemoType. Orders expire: deposit.expiresIn / status expiry.expiresIn
   give the remaining validity as a duration.
   For Lightning, pay the BOLT11 in source.lnInvoice (receiverAddress is empty).

4) Poll until settled:
   curl "https://apiserver.mpprouter.dev/v1/services/rozo-agent-api/invoice-status?payment_id=<linkId>"
   and re-GET the payments/<rozoPaymentId> URL above. The Coinbase link is settled
   only when the router reports paid / coinbase.settled — an intents status of
   payment_completed alone is the bridge lifecycle, not final settlement.

## Safety rules (encode these, they prevent fund loss)

- Before paying, require: status == "payment_unpaid" AND source.txHash == null AND
  source.amountReceived in {null,"0"} AND source.confirmedAt == null. Anything else
  means the order is already funded — do NOT pay again; escalate for reconciliation.
- Deposit addresses are one-time and quote-bound. Never reuse an address from an old
  order, a cached response, or a document. Always re-fetch step 3 in the same run.
- Respect expiry with margin: do not send if now > min(order expiresAt, Coinbase
  link expiry) minus a safety margin (10 min EVM/Stellar, 5 min Solana; Lightning:
  only pay a BOLT11 with >= 10 min validity left).
- Re-check step 4 payability immediately before broadcasting a transaction: the
  Coinbase link can be consumed by another payer at any moment.
- Wrong token, wrong network, wrong amount, or paying twice is usually unrecoverable.
- After any on-chain payment is detected, never retry into a new order and never
  label the payment a normal failure — keep the tx hash and rozoPaymentId, keep
  polling, and escalate if it stays stuck.

## Errors

409 = link already used · 410 = link expired · UNSUPPORTED_SOURCE = the response's
"supported" object lists valid (chainId, tokenSymbol) pairs (Lightning is supported
but omitted from that list) · RATE_LIMITED = per-IP creation cap, retry later.