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Subscribe via eth_subscribe to receive each transaction as it is pre-confirmed into a Flashblock. Pass true as the second parameter to receive full transaction and log data.
Only available on Flashblocks WebSocket endpoints: wss://mainnet-preconf.base.org / wss://sepolia-preconf.base.org.
Requires base/base minimum client version v0.3.1.
Each subscription emits one item per WebSocket message. Events arrive approximately every 200ms. If your handler performs heavy processing per event, throttle or debounce it to avoid blocking.

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Parameters

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subscriptionType
string
required
Must be "newFlashblockTransactions".
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full
boolean
If true, each notification includes the full transaction object and associated logs. Defaults to false (minimal data only).

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Returns

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result
string
Hex-encoded subscription ID.

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Example

{"jsonrpc": "2.0", "id": 1, "method": "eth_subscribe", "params": ["newFlashblockTransactions"]}