# Relay & SDK overview

The managed relay lets your users transact **gaslessly**. A user signs a 7702
authorization and a batch digest; Kryard signs, fronts the gas, and broadcasts the
EIP-7702 **type-4** transaction. Your user gets smart-wallet-grade UX — batched
calls, no native ETH required — with no 4337 bundler.

## The flow

1. The user's EOA signs a **7702 authorization** delegating its code to a delegate
   contract for one transaction.
2. The user signs the **batch digest** (the calls to run as the EOA).
3. Your backend submits both to Kryard's relay route, authenticated with `X-Stamp`.
4. Kryard's relayer key signs and broadcasts the type-4 transaction, **paying the
   gas**. Usage is metered against your prepaid gas tank.
5. You poll the relay until the transaction is `confirmed`.

## What the SDK gives you

- `KryardRelayClient` — the X-Stamp-authed relay client (`submit` / `get`).
- `sponsorExecute` — sponsor a batch through the reference `KryardDelegate`.
- `sponsorCall` — delegate-agnostic: bring your own 7702 delegate.
- `createApiKeyStamper` — a built-in, dependency-light X-Stamp signer (MIT).

## Next

- [Quickstart](/relay/quickstart) — install and sponsor your first batch.
- [Pay gas in any token](/relay/erc20-gas) — ERC-20 gas reimbursement.
- [Custom delegate](/relay/sponsor-call) — `sponsorCall` with your own delegate.
- [API reference](/api/relay-routes) — the raw relay routes.