# Bolt Protocol

> Bolt Protocol is a payment relay on Stacks (Bitcoin L2). It sponsors your transactions, so you can move sBTC and USDCx, or call any contract, without holding STX: the fee is paid in sBTC or USDCx. Non-custodial: you sign every transaction with your own key; Bolt only adds the sponsor signature and broadcasts. No API key, no signup.

Base URL: `https://boltproto.org/api` (mainnet). JSON over HTTPS.

Two ways to use it:

- **Gasless transfer**: send sBTC or USDCx to any Stacks address. Fee from 10 sats (sBTC) or 0.0001 USDCx, taken inside the same transaction. One POST.
- **Prepaid gas credit** (sBTC only): deposit sBTC once, then have Bolt sponsor any contract call you sign (SIP-010 transfers, registrations, DeFi calls). Bolt holds the credit balance; each call debits it, and what you do not use can be withdrawn.

## Docs

- [Full API guide for agents](https://boltproto.org/llms-full.txt): endpoints, contract addresses, how to build and sign the transactions, errors, a runnable example.

## Optional

- [Wallet UI](https://boltproto.org/): the same API used by a human-facing web wallet.
- [Health check](https://boltproto.org/api/health)