Signature Subscription

Overview

Meaning and scope

Signature Subscription is a Solana WebSocket RPC subscription that sends status notifications for one specified transaction signature until a terminal confirmation notification is delivered. It monitors transaction status and is unrelated to subscribing for cryptographic signing services or reusable signature authorization.

Mechanism and operation

A Signature Subscription handler should acknowledge only after durable receipt when the provider’s retry contract depends on the response. A production implementation should use the correct signature and commitment, handle an optional received notification separately from confirmation, detect disconnects, query transaction status after gaps, and close local resources after termination. Business actions triggered by Signature Subscription should be idempotent and should verify the current object state before fulfillment or accounting updates. Useful measures include subscription setup failures, time to received and terminal notification, disconnect rate, fallback query use, duplicate notifications, and unresolved signatures.

Practical payment example

A Solana client subscribes to updates for a transaction signature. After receiving a notification, it fetches the transaction result under the configured commitment policy instead of treating any subscription message as final success.

Operational checks

Monitoring for Signature Subscription should track delivery age, signature failures, duplicate rate, retry exhaustion, and unresolved business events. Replay of Signature Subscription should preserve original identifiers and timestamps so historical processing cannot masquerade as a new event. For Signature Subscription, the event identifier, signature result, delivery attempt, and resulting business state should remain connected throughout processing.

Distinctions and limits

The principal risks include treating receipt as confirmation, missed terminal messages after disconnect, wrong commitment assumptions, provider-specific availability, duplicate notifications, and keeping stale subscriptions indefinitely. A receiver should treat transport acknowledgement and successful downstream processing as separate states for Signature Subscription.

Related reading

Related definitions: RPC Subscription, Transaction Query.