signatureSubscribe

The signatureSubscribe method creates a subscription that sends a notification when a specific transaction signature reaches the specified commitment level.

📘 Usage Notes

• This method must be called via a WebSocket endpoint. HTTP is not supported.
• This is a one-time notification subscription. The subscription is automatically cancelled after the server sends a signatureNotification.
• CU is consumed based on the volume of subscribed data. Use appropriate filtering options to subscribe only to the data you need.

---

1. Request

Parameters

The signature subscription request accepts the following parameters.

Parameter	Type	Required	Description
id	integer or string	required	A unique identifier for the request, used by the client to match requests with responses.
jsonrpc	string	required	The JSON-RPC protocol version. Always set to "2.0".
method	string	required	The name of the method to invoke. Set to "signatureSubscribe".
params	array	required	Signature information and options to subscribe to. The first element is the transaction signature; the second is a configuration object.
params[0]	string	required	The transaction signature to subscribe to (base-58 encoded string). Must be the first signature of the transaction.
params[1].commitment	string	optional	Specifies the level of block finalization. - finalized: Queries the most recent block confirmed as finalized by a supermajority of the cluster at maximum lockout. - confirmed: Queries the most recent block voted on by a supermajority of the cluster. - processed: Queries the node's most recent block, which may still be skipped by the cluster.
params[1].enableReceivedNotification	boolean	optional	Specifies whether to also receive a notification when the signature is received by the RPC node. When true, notifications are sent both on receipt and on processing completion.

Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "signatureSubscribe",
  "params": [
    "2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b",
    {
      "commitment": "finalized",
      "enableReceivedNotification": false
    }
  ]
}

---

2. Response

Subscription Response

On success, the server returns a subscription ID.

{
  "jsonrpc": "2.0",
  "result": 0,
  "id": 1
}

This subscription ID is required when calling the signatureUnsubscribe method.

Notifications

Once the subscription is active, the server pushes a notification when the transaction reaches the specified commitment level.

Notification format:

Field	Type	Description
slot	u64	The slot number
value	object | string	RpcSignatureResult notification value

value field details:

• Signature received notification (when enableReceivedNotification is true and the signature is received):

  • Type: string
  • Value: "receivedSignature"
  • Description: Indicates that the signature has been received by the RPC node.

• Transaction processing completion notification (when the signature has been processed):

  • Type: object
  • Value: { "err": null } (success) or { "err": TransactionError } (failure)
  • Description: Indicates that the transaction has been processed at the specified commitment level.

Examples

{
  "jsonrpc": "2.0",
  "method": "signatureNotification",
  "params": {
    "result": {
      "context": {
        "slot": 5207624
      },
      "value": {
        "err": null
      }
    },
    "subscription": 24006
  }
}

{
  "jsonrpc": "2.0",
  "method": "signatureNotification",
  "params": {
    "result": {
      "context": {
        "slot": 5207624
      },
      "value": "receivedSignature"
    },
    "subscription": 24006
  }
}

---

3. How to Use

Connect to WebSocket Channel

wscat -c wss://api.mainnet-beta.solana.com

Subscribe to Signature

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "signatureSubscribe",
  "params": [
    "2EBVM6cB8vAAD93Ktr6Vd8p67XPbQzCJX47MpReuiCXJAtcjaxpvWpcg9Ege1Nr5Tk3a2GFrByT7WPBjdsTycY9b",
    {
      "commitment": "finalized",
      "enableReceivedNotification": false
    }
  ]
}

Receive Notification

• Initial response: a subscription ID is returned.
• Subsequent: when the transaction reaches the specified commitment level, the server automatically sends a notification. The subscription is automatically cancelled after the notification is received (one-time notification subscription).

Unsubscribe

There are two ways to cancel a subscription:

1. Close the connection: Press CTRL+C in the terminal to close the WebSocket connection. All active subscriptions are automatically cancelled.

2. Cancel a specific subscription: Use signatureUnsubscribe to cancel a specific subscription while keeping the connection open.

Unsubscribe request:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "signatureUnsubscribe",
  "params": [10]
}

Response after unsubscribing:

{
  "jsonrpc": "2.0",
  "result": true,
  "id": 2
}