[Smart Accounts Kit] Add redelegation guide

gator-sidebar.js

@@ -79,6 +79,7 @@ const sidebar = {
                 'guides/delegation/use-delegation-scopes/constrain-scope',
               ],
             },
+            'guides/delegation/create-redelegation',
             'guides/delegation/check-delegation-state',
             'guides/delegation/disable-delegation',
           ],

smart-accounts-kit/guides/delegation/create-redelegation.md

@@ -0,0 +1,148 @@
+---
+description: Learn how to create a redelegation.
+sidebar_label: Create a redelegation
+toc_max_heading_level: 3
+keywords: [delegation, state, caveat enforcer, delegation scope, redelegation]
+---
+
+import Tabs from "@theme/Tabs";
+import TabItem from "@theme/TabItem";
+
+# Create a redelegation
+
+Redelegation is a core feature that sets delegations apart from other permission sharing frameworks.
+It allows a delegate to create a delegation chain, passing on the same or reduced level of authority 
+from the root delegator.
+
+For example, if Alice grants Bob permission to spend 10 USDC on her behalf, Bob can further grant Carol
+permission to spend up to 5 USDC on Alice's behalf-that is, Bob can redelegate. This creates a delegation 
+chain where the root permissions are reshared with additional parties.
+
+## Prerequisites
+
+- [Install and set up the Smart Accounts Kit](../../get-started/install.md).
+- [Learn how to create a delegation](execute-on-smart-accounts-behalf.md).
+
+## Create a delegation
+
+Create a [root delegation](../../concepts/delegation/index.md#delegation-types) from Alice to Bob.
+
+This example uses the [`erc20TransferAmount`](use-delegation-scopes/spending-limit.md#erc-20-transfer-scope) scope, allowing 
+Alice to delegate to Bob the ability to spend 10 USDC on her behalf. 
+
+<Tabs>
+<TabItem value="delegation.ts">
+
+```typescript
+import { aliceSmartAccount, bobSmartAccount } from "./config.ts";
+import { createDelegation } from '@metamask/smart-accounts-kit'
+import { parseUnits } from 'viem'
+
+const delegation = createDelegation({
+  scope: {
+    type: "erc20TransferAmount",
+    tokenAddress: "0xc11F3a8E5C7D16b75c9E2F60d26f5321C6Af5E92",
+    // USDC has 6 decimal places.
+    maxAmount: parseUnits("10", 6),
+  },
+  to: bobSmartAccount.address,
+  from: aliceSmartAccount.address,
+  environment: aliceSmartAccount.environment,
+})
+
+const signedDelegation = aliceSmartAccount.signDelegation({ delegation })
+```
+
+</TabItem>
+<TabItem value="config.ts">
+
+```typescript
+import { Implementation, toMetaMaskSmartAccount } from "@metamask/smart-accounts-kit"
+import { privateKeyToAccount } from "viem/accounts"
+import { createPublicClient, http } from "viem"
+import { sepolia as chain } from "viem/chains"
+
+const publicClient = createPublicClient({
+  chain,
+  transport: http(),
+})
+
+const aliceAccount = privateKeyToAccount("0x...")
+const bobAccount = privateKeyToAccount("0x...")
+
+export const aliceSmartAccount = await toMetaMaskSmartAccount({
+  client: publicClient,
+  implementation: Implementation.Hybrid,
+  deployParams: [aliceAccount.address, [], [], []],
+  deploySalt: "0x",
+  signer: { account: aliceAccount },
+})
+
+export const bobSmartAccount = await toMetaMaskSmartAccount({
+  client: publicClient,
+  implementation: Implementation.Hybrid,
+  deployParams: [bobAccount.address, [], [], []],
+  deploySalt: "0x",
+  signer: { account: bobAccount },
+})
+```
+
+</TabItem>
+</Tabs>
+
+## Create a redelegation
+
+Create a [redelegation](../../concepts/delegation/index.md#delegation-types) from Bob to Carol. When creating a redelegation, you can only narrow the scope of the original authority, not expand it. 
+
+To create a redelegation, provide the signed delegation as the `parentDelegation` argument when calling [createDelegation](../../reference/delegation/index.md#createdelegation).
+This example uses the [`erc20TransferAmount`](use-delegation-scopes/spending-limit.md#erc-20-transfer-scope) scope, allowing 
+Bob to delegate to Carol the ability to spend 5 USDC on Alice's behalf.
+
+<Tabs>
+<TabItem value="redelegation.ts">
+
+```typescript
+import { bobSmartAccount, carolSmartAccount } from "./config.ts"
+import { createDelegation } from '@metamask/smart-accounts-kit'
+import { parseUnits } from 'viem'
+
+const redelegation = createDelegation({
+  scope: {
+    type: "erc20TransferAmount",
+    tokenAddress: "0xc11F3a8E5C7D16b75c9E2F60d26f5321C6Af5E92",
+    // USDC has 6 decimal places.
+    maxAmount: parseUnits("5", 6),
+  },
+  to: carolSmartAccount.address,
+  from: bobSmartAccount.address,
+  // Signed root delegation from previous step.
+  parentDelegation: signedDelegation,
+  environment: bobSmartAccount.environment,
+})
+
+const signedRedelegation = bobSmartAccount.signDelegation({ delegation: redelegation })
+```
+
+</TabItem>
+<TabItem value="config.ts">
+
+```typescript
+// Update the existing config to create a smart account for Carol.
+
+const carolAccount = privateKeyToAccount("0x...")
+
+export const carolSmartAccount = await toMetaMaskSmartAccount({
+  client: publicClient,
+  implementation: Implementation.Hybrid,
+  deployParams: [carolAccount.address, [], [], []],
+  deploySalt: "0x",
+  signer: { account: carolAccount },
+})
+```
+
+</TabItem>
+</Tabs>
+
+## Next steps
+
+- See [how to disable a delegation](disable-delegation.md) to revoke permissions.