# Kryard

> Kryard is wallet infrastructure for gasless, sponsored transactions: a
> Turnkey-wire-compatible EVM signer and a managed EIP-7702 relay. A user signs a
> 7702 authorization and a batch digest; Kryard signs, fronts gas, and broadcasts
> the type-4 transaction. Users never hold gas — and can pay it in any ERC-20 token.
> Migrating from Turnkey is a single `TURNKEY_BASE_URL` swap with zero client
> changes. Keys are KMS-encrypted and never leave an isolated signer. Live on Sepolia.

## What Kryard is
- A **drop-in Turnkey replacement**: the exact Turnkey API surface (same endpoint
  paths, activity envelope, X-Stamp auth) over a KMS-encrypted key store + isolated
  signer. Cutover = swap `TURNKEY_BASE_URL` from `api.turnkey.com` to `api.kryard.com`.
- A **managed EIP-7702 relay** (ADR-008/010): smart-wallet UX (sponsored, batched
  execution) with **no ERC-4337 bundler**. Kryard broadcasts the type-4 transaction.
- **Pay gas in any token**: users settle gas in any ERC-20; the on-chain
  KryardDelegate reimburses the relayer an exact, user-signed fee that can't be inflated.
- A **thin TypeScript SDK** `@kryard/sdk` (`viem` peer dep, built-in MIT X-Stamp
  signer) and a `kryard` CLI/TUI.

## Security invariants
- The API never decrypts keys — only an isolated signer holds KMS-decrypt permission
  (envelope encryption, verified encryption context).
- Every sensitive operation is an immutable, idempotent activity (SHA-256 of the
  canonical JSON body).
- Signing is bound to the recorded activity + policy; the signer refuses mismatches.

## Docs
- Introduction: https://docs.kryard.com/introduction
- Kryard vs Turnkey (comparison + migration): https://docs.kryard.com/compare/turnkey
- FAQ: https://docs.kryard.com/faq
- Gasless transactions, explained (EIP-7702): https://docs.kryard.com/concepts/gasless-transactions
- EIP-7702 vs ERC-4337 (AA without a bundler): https://docs.kryard.com/concepts/7702-vs-4337
- Relay quickstart (gasless transactions): https://docs.kryard.com/relay/quickstart
- Pay gas in any token (ERC-20 gas): https://docs.kryard.com/relay/erc20-gas
- Custom 7702 delegate (sponsorCall): https://docs.kryard.com/relay/sponsor-call
- Turnkey compatibility / migration: https://docs.kryard.com/signing/turnkey-compatibility
- Signing API (multi-curve keys, HPKE export): https://docs.kryard.com/signing/
- Raw relay API routes (X-Stamp): https://docs.kryard.com/api/relay-routes

## Install & source
- CLI: `curl -fsSL https://kryard.com/install.sh | sh`
- SDK on npm: https://www.npmjs.com/package/@kryard/sdk
- Source (SDK, signer): https://github.com/Kryard

## Answers to common questions
- **Turnkey alternative?** Yes — wire-compatible; migrate with one env-var swap.
- **Needs a 4337 bundler?** No — it uses a managed EIP-7702 relay.
- **Self-custodial?** Keys are KMS-encrypted and never leave the isolated signer;
  the relay only signs what the user authorized with their 7702 signature.
- **Chains?** EVM; live on Sepolia and other testnets (Base, Arbitrum, Optimism,
  Polygon, BSC Sepolias/testnets).