---
title: Bundle & New RPC Methods
description:
  New RPC methods in Kora v2.2.0-beta — Jito bundles, version, and bundle fee
  estimation.
---

These methods are available starting in `v2.2.0-beta.1`. Enable them in your
`kora.toml` under `[kora.enabled_methods]`.

## getVersion

Retrieves the Kora server version information.

### JSON-RPC Request

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getVersion",
  "params": {}
}
```

### JSON-RPC Response

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "version": "2.2.0-beta.7"
  }
}
```

### cURL Example

```bash
curl -X POST http://localhost:8080 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"getVersion","params":{}}'
```

### TypeScript SDK

```typescript
const result = await client.getVersion();
console.log("Kora version:", result.version);
```

### Configuration

```toml
[kora.enabled_methods]
get_version = true
```

---

## estimateBundleFee

Calculates the combined fee for multiple transactions in a bundle. Useful for
determining the total cost before signing and submitting a bundle.

> **Note:** Transaction plugins (e.g., `gas_swap`) are **not** executed during
> fee estimation. Plugins only run during signing flows (`signBundle`,
> `signAndSendBundle`).

### JSON-RPC Request

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "estimateBundleFee",
  "params": {
    "transactions": ["base64EncodedTransaction1", "base64EncodedTransaction2"],
    "fee_token": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v"
  }
}
```

### Parameters

| Parameter      | Type     | Required | Description                                  |
| -------------- | -------- | -------- | -------------------------------------------- |
| `transactions` | string[] | Yes      | Array of base64-encoded transactions (max 5) |
| `fee_token`    | string   | Yes      | Token mint for fee calculation               |

### JSON-RPC Response

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "total_fee_in_lamports": "15000",
    "total_fee_in_token": "150",
    "fee_token": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "transaction_fees": [
      {
        "fee_in_lamports": "5000",
        "fee_in_token": "50"
      },
      {
        "fee_in_lamports": "10000",
        "fee_in_token": "100"
      }
    ]
  }
}
```

### cURL Example

```bash
curl -X POST http://localhost:8080 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "estimateBundleFee",
    "params": {
      "transactions": ["base64Tx1", "base64Tx2"],
      "fee_token": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v"
    }
  }'
```

### TypeScript SDK

```typescript
const estimate = await client.estimateBundleFee({
  transactions: [base64Tx1, base64Tx2, base64Tx3],
  fee_token: "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v"
});
console.log("Total fee:", estimate.total_fee_in_lamports, "lamports");
console.log("Total fee in token:", estimate.total_fee_in_token);
```

### Configuration

```toml
[kora.enabled_methods]
estimate_bundle_fee = true

[kora.bundle]
enabled = true
```

---

## signBundle

Signs multiple transactions as a bundle without submitting them to the network.
Use this when you want to handle bundle submission to Jito yourself.

This method is protected by reCAPTCHA when configured. Include the
`x-recaptcha-token` header if your server has reCAPTCHA enabled.

When
[transaction plugins](/docs/tools/kora/beta/configuration#transaction-plugins)
are enabled (e.g., `gas_swap`), each transaction in the bundle is validated
against the plugin rules before signing.

### Lighthouse Fee Payer Protection

When
[Lighthouse protection](/docs/tools/kora/beta/configuration#lighthouse-fee-payer-protection)
is enabled, Kora adds a balance assertion instruction to the **last
transaction** in the bundle. This protects the fee payer from drainage attacks
by ensuring the balance doesn't drop below expected levels after all bundle
transactions complete.

**Important:** Since Lighthouse modifies the transaction message, any
pre-existing client signatures on the last transaction become invalid. Clients
must **re-sign** after receiving the modified bundle back from Kora.

```
signBundle → client receives modified txs → client re-signs last tx → client sends bundle
```

### JSON-RPC Request

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "signBundle",
  "params": {
    "transactions": [
      "base64EncodedTransaction1",
      "base64EncodedTransaction2",
      "base64EncodedTransaction3"
    ],
    "signer_key": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
  }
}
```

### Parameters

| Parameter              | Type     | Required | Description                                         |
| ---------------------- | -------- | -------- | --------------------------------------------------- |
| `transactions`         | string[] | Yes      | Array of base64-encoded transactions (max 5)        |
| `signer_key`           | string   | No       | Specific signer to use (defaults to pool selection) |
| `transactions_to_sign` | number[] | No       | Indices of transactions to sign (defaults to all)   |

### JSON-RPC Response

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "signed_transactions": [
      "base64EncodedSignedTransaction1",
      "base64EncodedSignedTransaction2",
      "base64EncodedSignedTransaction3"
    ],
    "signer_pubkey": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
  }
}
```

### cURL Example

```bash
curl -X POST http://localhost:8080 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "signBundle",
    "params": {
      "transactions": ["base64Tx1", "base64Tx2"],
      "signer_key": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
    }
  }'
```

### TypeScript SDK

```typescript
const result = await client.signBundle({
  transactions: [base64Tx1, base64Tx2, base64Tx3],
  signer_key: koraSignerAddress
});
console.log("Signed transactions:", result.signed_transactions);
```

### Partial Bundle Signing

Use `transactions_to_sign` to sign only specific transactions in the bundle:

```typescript
// Only sign transactions at index 0 and 2
const result = await client.signBundle({
  transactions: [tx1, tx2, tx3, tx4],
  transactions_to_sign: [0, 2]
});
// tx1 and tx3 are signed by Kora, tx2 and tx4 remain unchanged
```

### Configuration

```toml
[kora.enabled_methods]
sign_bundle = true

[kora.bundle]
enabled = true
```

---

## signAndSendBundle

Signs and submits a bundle of up to 5 transactions to Jito's block engine. All
transactions in the bundle execute atomically and sequentially — either all
succeed or none do.

This method is protected by reCAPTCHA when configured. Include the
`x-recaptcha-token` header if your server has reCAPTCHA enabled.

When
[transaction plugins](/docs/tools/kora/beta/configuration#transaction-plugins)
are enabled (e.g., `gas_swap`), each transaction in the bundle is validated
against the plugin rules before signing.

> **Note:**
> [Lighthouse fee payer protection](/docs/tools/kora/beta/configuration#lighthouse-fee-payer-protection)
> does **not** apply to this method. Since bundles are sent immediately, adding
> a Lighthouse assertion would invalidate existing client signatures. If you
> need Lighthouse protection, use [`signBundle`](#signbundle) and handle Jito
> submission yourself after re-signing.

### JSON-RPC Request

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "signAndSendBundle",
  "params": {
    "transactions": [
      "base64EncodedTransaction1",
      "base64EncodedTransaction2",
      "base64EncodedTransaction3"
    ],
    "signer_key": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
  }
}
```

### Parameters

| Parameter              | Type     | Required | Description                                         |
| ---------------------- | -------- | -------- | --------------------------------------------------- |
| `transactions`         | string[] | Yes      | Array of base64-encoded transactions (max 5)        |
| `signer_key`           | string   | No       | Specific signer to use (defaults to pool selection) |
| `transactions_to_sign` | number[] | No       | Indices of transactions to sign (defaults to all)   |

### JSON-RPC Response

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "bundle_uuid": "8f4a3b2c-1d5e-6f7a-8b9c-0d1e2f3a4b5c",
    "signed_transactions": [
      "base64EncodedSignedTransaction1",
      "base64EncodedSignedTransaction2",
      "base64EncodedSignedTransaction3"
    ],
    "signer_pubkey": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
  }
}
```

### cURL Example

```bash
curl -X POST http://localhost:8080 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "signAndSendBundle",
    "params": {
      "transactions": ["base64Tx1", "base64Tx2"],
      "signer_key": "3Z1Ef7YaxK8oUMoi6exf7wYZjZKWJJsrzJXSt1c3qrDE"
    }
  }'
```

### TypeScript SDK

```typescript
const { bundle_uuid } = await client.signAndSendBundle({
  transactions: [base64Tx1, base64Tx2, base64Tx3],
  signer_key: koraSignerAddress
});
console.log("Bundle submitted:", bundle_uuid);
```

### Configuration

```toml
[kora.enabled_methods]
sign_and_send_bundle = true

[kora.bundle]
enabled = true

[kora.bundle.jito]
block_engine_url = "https://mainnet.block-engine.jito.wtf"
```

> **Note:** When using bundles with Jito tips, ensure `allow_transfer = true` is
> set in `[validation.fee_payer_policy.system]` so the Kora signer can pay the
> tip.