Program subscribe · Blokboard

Program subscribe listens for changes to accounts owned by a Solana program. Use filters to limit the account data your workflow receives.

Try it step by step#

Enter the program ID you want to observe on the selected network.
Add a Filters JSON array only when you know that program’s account layout. dataSize filters account size; memcmp matches bytes at an offset.
Run and inspect accountId, account, and context.slot for a matching account change.

What to expect#

Notifications identify the changed account in accountId. It will usually differ from the programId that owns the account.

Things to check#

A program subscription observes account changes, not a decoded list of business events.
Incorrect size or byte filters can silently match no accounts. Start with a known account layout.
Use Logs subscribe if you need transaction log messages instead.

Keep learning#

Network setup: This node uses solana. See connections for RPC setup and Test mode for network selection.

Parameters#

Setting	Default	What it does
Program ID	—	Program whose owned accounts should be observed.
Account filters	`(empty)`	Optional JSON array of dataSize or memcmp filters.
Account data	`base64`	How account data is encoded in notifications. Base64 returns encoded bytes.
Commitment	`confirmed`	How far a Solana block must be confirmed before its data is used.
RPC URL	`{{global.chains.solana.rpcUrl}}`	Configured for Solana in workspace RPC settings.
Timeout (seconds)	`0`	Use 0 to wait until a matching notification arrives or the workflow is stopped.
On failure	`stop`	Choose whether a failed execution stops the workflow or only ends this path.
Retry attempts	`5`	How many times to reconnect after the subscription connection fails.

Account filters: Available under More options.

Account data: Choices: Base64 (base64), Base58 (base58), Base64 + zstd (base64+zstd), JSON parsed (jsonParsed). Available under More options.

Commitment: Choices: Processed (processed), Confirmed (confirmed), Finalized (finalized). Available under More options.

RPC URL: Available under More options.

Timeout (seconds): Available under More options.

On failure: Choices: Stop workflow (stop), Continue (continue). Available under More options.

Retry attempts: Available under More options. Limits: minimum 0.

Inputs#

Port	Value
`in`	any

Outputs#

Port	Value	Description
`out`	object	The next changed account owned by the program.

out fields#

Field	Type
`programId`	string
`accountId`	string
`context.slot`	number
`account.lamports`	string
`account.lamportsNumber`	number
`account.owner`	string
`account.executable`	boolean
`account.rentEpoch`	number
`account.space`	number
`account.data`	any
`account.dataEncoding`	string