> ## 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.

# signatureSubscribe

> Subscribe to receive a notification when the transaction with the given signature reaches the specified commitment level.

This is a subscription to a single notification. It is automatically cancelled by the server once the notification, `signatureNotification`, is sent by the RPC.

## Endpoints

Websockets are available on mainnet and devnet with the following URLs:

* **Mainnet** `wss://mainnet.helius-rpc.com/?api-key=<api-key>`
* **Devnet** `wss://devnet.helius-rpc.com/?api-key=<api-key>`

<Note>Websockets have a 10-minute inactivity timer; implementing health checks and sending pings every minute is heavily recommended to keep the websocket connection alive.</Note>

## Authorizations

<ParamField query="api-key" type="string" required>
  Your Helius API key. You can get one for free in the [dashboard](https://dashboard.helius.dev/api-keys).
</ParamField>

## Body

<ParamField body="params" type="array" required>
  <Expandable title="properties" defaultOpen>
    <ParamField body="signature" type="string" required>
      Transaction signature, as base-58 encoded string.

      The transaction signature must be the first signature from the transaction (see transaction id for more details).
    </ParamField>

    <ParamField body="config" type="object">
      Configuration object containing the following fields:

      <ParamField body="commitment" type="string">
        The commitment level for the subscription. Can be `finalized`, `confirmed`, or `processed`.
      </ParamField>

      <ParamField body="enableReceivedNotification" type="boolean">
        Whether to send a notification when the transaction signature is received.
      </ParamField>
    </ParamField>
  </Expandable>
</ParamField>

## Response

<ResponseField name="result" type="integer">
  Subscription id (needed to unsubscribe)
</ResponseField>

## Notification Format

The notification will be an RpcResponse JSON object with value containing an object with:

* `slot: <u64>` - The corresponding slot.
* `value: <object|string>` - a notification value of RpcSignatureResult, resulting in either:
  * when `enableReceivedNotification` is `true` and the signature is received: the literal string `"receivedSignature"`, or
  * when the signature is processed: `err: <object|null>`:
    * `null` if the transaction succeeded in being processed at the specified commitment level, or
    * a TransactionError, if the transaction failed

<RequestExample>
  ```json Request theme={"system"}
  {
    "jsonrpc": "2.0",
    "id": 1,
    "method": "signatureSubscribe",
    "params": [
      "2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b",
      {
        "commitment": "finalized",
        "enableReceivedNotification": false
      }
    ]
  }
  ```
</RequestExample>

<ResponseExample>
  ```json Response theme={"system"}
  {
    "jsonrpc": "2.0",
    "result": 0,
    "id": 1
  }
  ```

  ```json Notification (Processed Transaction) theme={"system"}
  {
    "jsonrpc": "2.0",
    "method": "signatureNotification",
    "params": {
      "result": {
        "context": {
          "slot": 5207624
        },
        "value": {
          "err": null
        }
      },
      "subscription": 24006
    }
  }
  ```

  ```json Notification (Received Transaction) theme={"system"}
  {
    "jsonrpc": "2.0",
    "method": "signatureNotification",
    "params": {
      "result": {
        "context": {
          "slot": 5207624
        },
        "value": "receivedSignature"
      },
      "subscription": 24006
    }
  }
  ```
</ResponseExample>