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

# sendBundle

> Submit an atomic bundle of up to 5 signed transactions via Jito's Block Engine. Proxied through your Helius RPC endpoint.

Submit a bundle of up to 5 fully-signed transactions for atomic execution. All transactions execute sequentially — if any fails, the entire bundle is rejected.

Requires a tip to a [Jito tip account](https://www.helius.dev/docs/sending-transactions/send-bundle.md#tip-accounts) in at least one transaction.

## Rate Limits

`sendBundle` is rate limited to **5 requests per second per project**. `getBundleStatuses` and `simulateBundle` use the general RPC rate limit.

> [!TIP]
>
> Need higher rate limits? [Contact our sales team](https://www.helius.dev/contact).

## Endpoint

```
POST https://mainnet.helius-rpc.com/?api-key=YOUR_API_KEY
```

## Request

**jsonrpc** `string` *required*

`"2.0"`

**id** `number` *required*

Request identifier.

**method** `string` *required*

`"sendBundle"`

**params\[0]** `array[string]` *required*

Array of up to 5 fully-signed transactions, base64 encoded.

**params\[1].encoding** `string`

`"base64"` (recommended) or `"base58"`. Default: `"base58"`.

## Query Parameters

**mev-protect** `boolean` (default: false)

When true, routes your bundle away from validators statistically linked to sandwich attacks. Opt-in per request. See [MEV Protect](https://www.helius.dev/docs/sending-transactions/mev-protect.md).

## Headers

**jito-region** `string`

Optional. Route to a specific Jito Block Engine region. Values: `ams`, `dub`, `fra`, `lon`, `nyc`, `slc`, `sgp`, `tyo`, `mainnet`. If omitted, routes to the global endpoint (geo-routed to nearest).

## Request Example

```bash theme={"system"}
curl "https://mainnet.helius-rpc.com/?api-key=YOUR_API_KEY" \
  -X POST \
  -H "Content-Type: application/json" \
  -H "jito-region: nyc" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendBundle",
    "params": [
      [
        "BASE64_SIGNED_TX_1",
        "BASE64_SIGNED_TX_2"
      ],
      {
        "encoding": "base64"
      }
    ]
  }'
```

## Response

**result** `string`

Bundle ID (SHA-256 hash of the transaction signatures). Use with `getBundleStatuses` to track landing.

```json theme={"system"}
{
  "jsonrpc": "2.0",
  "result": "892b79ed49138bfb3aa5441f0df6e06ef34f9ee8f3976c15b323605bae0cf51d",
  "id": 1
}
```

## See Also

* [Jito Bundles via Helius](https://www.helius.dev/docs/sending-transactions/send-bundle.md) — full guide with region routing, tip accounts, and requirements
* [getBundleStatuses](https://www.helius.dev/docs/api-reference/sender/getbundlestatuses.md) — check bundle landing status
* [simulateBundle](https://www.helius.dev/docs/api-reference/rpc/http/simulatebundle.md) — test bundles before submitting


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