docs: dfns new signer

site/.vitepress/config.ts

@@ -101,6 +101,7 @@ export default defineConfig({
                   { text: "Capsule", link: "/capsule" },
                   { text: "Lit Protocol", link: "/lit" },
                   { text: "Particle Network", link: "/particle-network" },
+                  { text: "Dfns", link: "/dfns" },
                   { text: "Externally Owned Account (EOA)", link: "/eoa" },
                   { text: "Using Your Own", link: "/custom-signer" },
                 ],

site/smart-accounts/signers/guides/dfns.md

@@ -0,0 +1,129 @@
+---
+outline: deep
+head:
+  - - meta
+    - property: og:title
+      content: Dfns
+  - - meta
+    - name: description
+      content: Guide for using Dfns as a signer
+  - - meta
+    - property: og:description
+      content: Guide for using Dfns as a signer
+---
+
+# Dfns Integration Guide
+
+[Dfns](https://www.dfns.co) is an MPC/TSS Wallet-as-a-Service API/SDK provider. We have optimized the balance of security and UX by deploying key shares into a decentralized network on the backend while enabling wallet access via biometric open standards on the frontend like Webauthn. [Ping us](https://www.dfns.co/learn-more) to set up a sandbox environment to get started.
+
+Dfns seamlessly integrates with Account Abstraction by signing User Operations. We've created a full example of a gasless transaction via a paymaster [in our SDK](https://github.com/dfns/dfns-sdk-ts/tree/m/examples/viem/alchemy-aa-gasless) adapted from Alchemy's [sponsor gas example](https://accountkit.alchemy.com/guides/sponsoring-gas.html). Clone the repo to get started and see the comments in the [Readme](https://github.com/dfns/dfns-sdk-ts/tree/m/examples/viem/alchemy-aa-gasless/README.md).
+
+## Install Dfns SDK
+
+::: code-group
+
+```bash [npm]
+npm i @dfns/lib-viem @dfns/sdk @dfns/sdk-keysigner
+```
+
+```bash [yarn]
+yarn add @dfns/lib-viem @dfns/sdk @dfns/sdk-keysigner
+```
+
+:::
+
+### Create a Dfns SmartAccountSigner
+
+Setup the Dfns Web3 Provider and wrap it in an AlchemyProvider. See the Dfns example [Readme](https://github.com/dfnsext/typescript-sdk/blob/m/examples/viem/alchemy-aa-gasless/README.md) for detail on populating the environment variables.
+
+```ts
+import {
+  LightSmartContractAccount,
+  getDefaultLightAccountFactoryAddress,
+} from "@alchemy/aa-accounts";
+import { AlchemyProvider } from "@alchemy/aa-alchemy";
+import { LocalAccountSigner } from "@alchemy/aa-core";
+import { DfnsWallet } from "@dfns/lib-viem";
+import { DfnsApiClient } from "@dfns/sdk";
+import { AsymmetricKeySigner } from "@dfns/sdk-keysigner";
+import dotenv from "dotenv";
+import { encodeFunctionData, parseAbi } from "viem";
+import { toAccount } from "viem/accounts";
+import { sepolia } from "viem/chains";
+
+dotenv.config();
+
+const initDfnsWallet = (walletId: string) => {
+  const signer = new AsymmetricKeySigner({
+    privateKey: process.env.DFNS_PRIVATE_KEY!,
+    credId: process.env.DFNS_CRED_ID!,
+    appOrigin: process.env.DFNS_APP_ORIGIN!,
+  });
+
+  const dfnsClient = new DfnsApiClient({
+    appId: process.env.DFNS_APP_ID!,
+    authToken: process.env.DFNS_AUTH_TOKEN!,
+    baseUrl: process.env.DFNS_API_URL!,
+    signer,
+  });
+
+  return DfnsWallet.init({
+    walletId,
+    dfnsClient,
+    maxRetries: 10,
+  });
+};
+
+const alchemyProvider = async (): Promise<AlchemyProvider> => {
+  const sepoliaWallet = await initDfnsWallet(process.env.SEPOLIA_WALLET_ID!);
+  const account = toAccount(sepoliaWallet);
+  const eoaSigner = new LocalAccountSigner(account);
+
+  return new AlchemyProvider({
+    apiKey: process.env.ALCHEMY_SEPOLIA_KEY!,
+    chain: sepolia,
+  }).connect(
+    (rpcClient) =>
+      new LightSmartContractAccount({
+        chain: sepolia,
+        owner: eoaSigner,
+        factoryAddress: getDefaultLightAccountFactoryAddress(sepolia),
+        rpcClient,
+      })
+  );
+};
+```
+
+### Execute a Gasless Transaction
+
+```ts
+const main = async () => {
+  const provider = await alchemyProvider();
+  const address = await provider.getAddress();
+  console.log(`Smart account address: ${address}`);
+
+  // link the provider with the Gas Manager. This ensures user operations
+  // sent with this provider get sponsorship from the Gas Manager.
+  provider.withAlchemyGasManager({
+    policyId: process.env.ALCHEMY_GAS_POLICY_ID!,
+  });
+
+  const alchemyToken = "0x6F3c1baeF15F2Ac6eD52ef897f60cac0B10d90C3";
+
+  // send a sponsored user operation to mint some tokens
+  const { hash: uoHash } = await provider.sendUserOperation({
+    target: alchemyToken,
+    data: encodeFunctionData({
+      abi: parseAbi(["function mint(address recipient)"]),
+      functionName: "mint",
+      args: [address],
+    }),
+  });
+  console.log(`User operation hash: ${uoHash}`);
+
+  const txHash = await provider.waitForUserOperationTransaction(uoHash);
+  console.log(`Transaction: https://sepolia.etherscan.io/tx/${txHash}`);
+};
+
+main();
+```