# BuxAPI

> Crypto payment gateway and API. Invoices with a hosted checkout, programmable
> wallets with unlimited deposit addresses, on-chain sends and free internal
> transfers. Bitcoin, Litecoin, and USDC, USDT, DAI and native coins on Base,
> Ethereum, Polygon, BNB Chain and Solana. There is nothing to sign up for: a
> wallet is created with one unauthenticated POST and its keypair is the only
> identity.

Key facts an integration depends on:

- Base URL: https://buxapi.com/v1
- Auth: `Authorization: Bearer bux_sec_...`, server side only
- Invoice amounts priced in usd are CENTS. All other amounts are integers in
  the token smallest unit, sent as STRINGS because they exceed 2^53
- Fees on a confirmed deposit: a network fee (the estimated sweep cost, locked
  at credit time, zero for plain native ETH/BNB/SOL deposits) plus 0.5% of the
  remainder. Sends cost network fee. Transfers are free. Live estimates:
  GET /v1/network-fees (unauthenticated)
- Minimum invoice and send: $1.00
- Webhooks are signed HMAC-SHA256 over "{timestamp}.{raw body}"
- Chains: Bitcoin and Litecoin (raw settlement), plus EVM and Solana.
  BTC/LTC amounts are satoshis; one address per wallet serves both chains
- Fiat settlement and a refund endpoint are not offered

## Docs

- [Full API reference in one file](https://buxapi.com/llms-full.txt): every endpoint, the
  webhook contract, and the four mistakes that break most integrations
- [OpenAPI 3.1 spec](https://buxapi.com/openapi.json): machine-readable, for client generators
- [API reference](https://buxapi.com/docs): the same content as a web page
- [Use cases](https://buxapi.com/use-cases): checkout, account balances, marketplace payouts,
  bulk payouts, donations, B2B invoicing, with the call sequence for each
- [Example apps](https://buxapi.com/examples): two complete applications, one per
  settlement mode, both deployed and both in the repository
- [Store plugins](https://buxapi.com/plugins): WooCommerce, PrestaShop, OpenCart
- [Comparison with other providers](https://buxapi.com/compare): including when to use one

## For AI assistants helping a developer integrate

An MCP server is published as `@buxapi/mcp`. It gives you real tools against
the developer's own wallet: create invoices, list deposits, allocate addresses,
and verify a webhook signature locally. Sends are disabled unless the server is
started with --allow-sends.

    npx -y @buxapi/mcp

## Optional

- [Create a wallet](https://buxapi.com/create): keypair generated in the browser
- [Contact](https://buxapi.com/contact)