signature
Emits a one-shot notification when a transaction signature reaches the requested commitment.
wss://ws-newyork.constant-k.com:1337/ws?api-key=YOUR_API_KEYsignatureSubscribe is the push equivalent of polling getSignatureStatuses for a single signature. It fires exactly one terminal notification — value.err is null on success or the transaction's error object on failure — once the signature reaches the requested commitment, and the server automatically unsubscribes afterward; calling signatureUnsubscribe is normally unnecessary.
Setting enableReceivedNotification adds an earlier, best-effort notification (value is the literal string "receivedSignature") the moment the node first sees the signature, before it has necessarily been processed at all — the basis for an optimistic "transaction received" UI state ahead of real confirmation.
Parameters
params is a JSON array, with values in this order: signature, config.
Base58-encoded transaction signature (the transaction's first/fee-payer signature) to watch.
Optional subscription settings.
Show propertiesProperties
How settled the account/transaction state must be before the node acts on it. processed is fastest and can roll back; finalized is slowest and never rolls back.
processedconfirmedfinalizedSends an extra early notification as soon as the node receives the signature, ahead of the terminal confirmation notification.
Result
The subscription id, returned once in the initial RPC response. Passed to signatureUnsubscribe, it cancels the stream before the terminal notification arrives.
Notifications
Updates arrive as signatureNotification messages on the same socket. For the terminal notification, result.value is {"err": null} on success or {"err": {...}} on failure. If enableReceivedNotification was set, an earlier notification may arrive first with result.value equal to the literal string "receivedSignature" instead of an object.
Notification payload.
Show propertiesProperties
Response context, including the slot the data was read at.
Show propertiesProperties
Slot number this applies to.
The requested data; see the fields below.
Show one ofOne of
Terminal notification: the transaction's outcome.
Show propertiesProperties
Null on success, or an error object/string describing the failure.
Early notification, only when enableReceivedNotification is true.
receivedSignatureUnsubscribe
signatureUnsubscribe, called with the subscription id, stops the notifications and returns true once the subscription is removed.
{
"jsonrpc": "2.0",
"id": 2,
"method": "signatureUnsubscribe",
"params": [61234]
}Notes
- WebSocket access is included on the Operator plan and above; it is not available on Free.
- Concurrent connections are capped per API key: 10 on Operator, 50 on Blade Runner, 100 on Nexus.
- Subscribe and unsubscribe calls draw from the same global per-plan request-rate limit as HTTP calls: 50 req/s on Operator, 200 req/s on Blade Runner, 500 req/s on Nexus.
- Only subscription methods (the
*Subscribe/*Unsubscribefamily) are accepted on the WebSocket endpoint; standard request/response RPC methods must go over HTTPS instead. - A
getHealthrequest sent over the open socket on a regular interval serves as a keepalive; connections that go quiet can be dropped by intermediate load balancers. - Each region has its own WebSocket hostname, for example
wss://ws-newyork.constant-k.com:1337/ws?api-key=YOUR_API_KEY; every region is listed on the Endpoints page. - Hand-built rather than captured live: catching a real, still-in-flight signature inside a short scripted WebSocket session isn't reliable, since the terminal notification only fires for state changes happening after the subscription starts.
- The subscription must start before, or immediately as, the transaction is sent. There is no historical replay: a signature that already reached the requested commitment before the subscription started produces no notification.