> ## Documentation Index
> Fetch the complete documentation index at: https://daehan-base.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# newFlashblockTransactions

> Subscribe to receive each transaction as it is pre-confirmed into a Flashblock. Only available on Flashblocks WebSocket endpoints.

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.

<Info>
  Only available on Flashblocks WebSocket endpoints: `wss://mainnet-preconf.base.org` / `wss://sepolia-preconf.base.org`.
</Info>

<Note>
  Requires [base/base](https://github.com/base/base) minimum client version v0.3.1.
</Note>

<Warning>
  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.
</Warning>

## Parameters

<ParamField body="subscriptionType" type="string" required>
  Must be `"newFlashblockTransactions"`.
</ParamField>

<ParamField body="full" type="boolean">
  If `true`, each notification includes the full transaction object and associated logs. Defaults to `false` (minimal data only).
</ParamField>

## Returns

<ResponseField name="result" type="string">
  Hex-encoded subscription ID.
</ResponseField>

## Example

<CodeGroup>
  ```json Subscribe theme={null}
  {"jsonrpc": "2.0", "id": 1, "method": "eth_subscribe", "params": ["newFlashblockTransactions"]}
  ```

  ```json Subscribe (full data) theme={null}
  {"jsonrpc": "2.0", "id": 1, "method": "eth_subscribe", "params": ["newFlashblockTransactions", true]}
  ```

  ```json Subscription ID Response theme={null}
  {"jsonrpc": "2.0", "id": 1, "result": "0x1887ec8b9589ccad00000000000532da"}
  ```
</CodeGroup>