siwa

# SIWA SDK 

Sign-In With Agent (SIWA) lets AI agents authenticate with services using their ERC-8004 onchain identity.

## Install

```bash
npm install @buildersgarden/siwa
```

## Skills

### Agent-Side (Signing)

Choose based on your wallet provider:

- [Bankr](https://siwa.id/skills/bankr/skill.md) — Bankr Agent API wallets
- [Circle](https://siwa.id/skills/circle/skill.md) — Circle developer-controlled wallets
- [Privy](https://siwa.id/skills/privy/skill.md) — Privy server wallets
- [Private Key](https://siwa.id/skills/private-key/skill.md) — Raw private key (viem LocalAccount)
- [Keyring Proxy](https://siwa.id/skills/keyring-proxy/skill.md) — Self-hosted proxy with optional 2FA

### Server-Side (Verification)

- [Server-Side Verification](https://siwa.id/skills/server-side/skill.md) — Next.js, Express, Hono, Fastify

## SDK Modules

| Import | Description |
|--------|-------------|
| `@buildersgarden/siwa` | Core: signSIWAMessage, verifySIWA, createSIWANonce, parseSIWAMessage, buildSIWAMessage, createClientResolver, parseChainId |
| `@buildersgarden/siwa/signer` | Signer factories (see wallet-specific skills above) |
| `@buildersgarden/siwa/erc8128` | ERC-8128 HTTP signing/verification |
| `@buildersgarden/siwa/receipt` | HMAC receipt helpers |
| `@buildersgarden/siwa/nonce-store` | Nonce stores (Memory, Redis, KV) |
| `@buildersgarden/siwa/identity` | SIWA_IDENTITY.md helpers |
| `@buildersgarden/siwa/registry` | Onchain agent registration |
| `@buildersgarden/siwa/client-resolver` | Dynamic PublicClient resolution for multi-chain servers |
| `@buildersgarden/siwa/next` | Next.js middleware (withSiwa, siwaOptions) |
| `@buildersgarden/siwa/express` | Express middleware (siwaMiddleware, siwaJsonParser, siwaCors) |
| `@buildersgarden/siwa/hono` | Hono middleware (siwaMiddleware, siwaCors) |
| `@buildersgarden/siwa/fastify` | Fastify middleware (siwaPlugin, siwaAuth) |
| `@buildersgarden/siwa/x402` | x402 payment helpers |
| `@buildersgarden/siwa/captcha` | Reve...