> ## Documentation Index
> Fetch the complete documentation index at: https://policykit.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Lit Client

> Integration with Lit Protocol for off-chain rule evaluation

# Lit Client

The `LitClient` integrates with Lit Protocol v8 (Naga network) to execute off-chain rule evaluations and produce signed attestations.

## Usage

```typescript theme={null}
import { LitClient } from "@policy-kit/sdk";

const lit = new LitClient({
  network: "naga",
  litActionCID: "QmLitActionCID...",
});

// Connect to the Lit network
await lit.connect();

// Request attestation for a transaction
const attestation = await lit.requestAttestation({
  policyCID: "QmPolicyCID...",
  target: "0xUniswapRouter",
  value: parseEther("1"),
  data: "0x38ed1739...",
  chainId: 84532,
});

console.log(attestation.signature);
console.log(attestation.deadline);

// Disconnect when done
await lit.disconnect();
```

## Constructor

```typescript theme={null}
new LitClient(config: LitConfig)
```

### LitConfig

| Option         | Type      | Required | Description                                  |
| -------------- | --------- | -------- | -------------------------------------------- |
| `network`      | `"naga"`  | Yes      | Lit Protocol network                         |
| `litActionCID` | `string`  | Yes      | CID of the deployed Lit Action               |
| `pkpPublicKey` | `string`  | No       | PKP public key (auto-provisioned if not set) |
| `debug`        | `boolean` | No       | Enable debug logging                         |

## Methods

### `connect()`

Connect to the Lit Protocol network. Must be called before any other method.

```typescript theme={null}
await lit.connect();
```

**Returns:** `Promise<void>`

### `disconnect()`

Disconnect from the Lit Protocol network. Should be called when done.

```typescript theme={null}
await lit.disconnect();
```

**Returns:** `Promise<void>`

### `requestAttestation(params)`

Execute the Lit Action to evaluate Tier 3 rules and produce a signed attestation.

```typescript theme={null}
const attestation = await lit.requestAttestation({
  policyCID: "QmPolicyCID",
  target: "0x...",
  value: parseEther("1"),
  data: "0x...",
  chainId: 84532,
});
```

| Parameter          | Type      | Description                  |
| ------------------ | --------- | ---------------------------- |
| `params.policyCID` | `string`  | IPFS CID of the policy       |
| `params.target`    | `Address` | Transaction target address   |
| `params.value`     | `bigint`  | Transaction ETH value        |
| `params.data`      | `Hex`     | Transaction calldata         |
| `params.chainId`   | `number`  | Chain ID for the transaction |

**Returns:** `Promise<Attestation>`

```typescript theme={null}
interface Attestation {
  signature: Hex;       // EIP-712 signature from PKP
  deadline: number;     // Expiration unix timestamp
  nonce: bigint;        // Attestation nonce
  pkpAddress: Address;  // Address of the signing PKP
}
```

The Lit Action performs the following:

1. Fetches the policy from IPFS
2. Evaluates all Tier 3 rules against the transaction
3. If all rules pass, threshold-signs an EIP-712 `PolicyApproval`
4. Returns the signature and metadata

### `isConnected()`

Check if the client is connected to the Lit network.

```typescript theme={null}
const connected = lit.isConnected();
```

**Returns:** `boolean`

## Attestation Format

The attestation uses the EIP-712 typed data standard:

```typescript theme={null}
const EIP712_TYPES = {
  PolicyApproval: [
    { name: "account", type: "address" },
    { name: "target", type: "address" },
    { name: "value", type: "uint256" },
    { name: "data", type: "bytes" },
    { name: "policyCID", type: "bytes32" },
    { name: "nonce", type: "uint256" },
    { name: "deadline", type: "uint256" },
  ],
};
```

## Error Handling

| Error                 | Description                      |
| --------------------- | -------------------------------- |
| `LitConnectionError`  | Failed to connect to Lit network |
| `LitActionError`      | Lit Action execution failed      |
| `LitAttestationError` | Attestation signing failed       |
| `LitTimeoutError`     | Lit Action exceeded timeout      |

## Lit Protocol Requirements

To use Tier 3 rules, you need:

1. **Lit Action deployed to IPFS** — Install `@policy-kit/lit-actions` and upload the pre-built bundle at `build/policyEvaluator.action.js` to IPFS to get the CID
2. **PKP (Programmable Key Pair)** — Provisioned through Lit Protocol
3. **Capacity Credits** — To pay for Lit network usage

```bash theme={null}
pnpm add @policy-kit/lit-actions
```

The `@policy-kit/lit-actions` package includes the pre-built action bundle ready for IPFS upload, as well as the source rule implementations in `src/rules/` that you can use as reference for custom rules.

<Note>
  The `LitClient` requires peer dependencies: `@lit-protocol/lit-client`, `@lit-protocol/networks`, and `@lit-protocol/auth`. Install them separately.
</Note>