> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bloklake.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Log fields

> Every field of the logs row type: request name, output column, Arrow type, JSON form and nullability.

One row per event log, ordered by `(block_number, log_index)`.

Select fields under `fields.log` by the name shown in bold; each comes back under its **column** name, with the Arrow type shown next to the name.

`topics` (request only) selects `topic0`–`topic3` at once.

## Fields

**blockNumber** `UInt64`

Number of the block containing the log.

Column `block_number` · JSON number · never null

**logIndex** `UInt32`

Position of the log in the block, counting from 0 across all transactions.

Column `log_index` · JSON number · never null

**transactionHash** `FixedSizeBinary(32)`

Hash of the transaction that emitted the log.

Column `transaction_hash` · JSON hex string · never null

**transactionIndex** `UInt32`

Position of that transaction in the block.

Column `transaction_index` · JSON number · never null

**address** `FixedSizeBinary(20)`

Contract that emitted the log. **Filterable** (`address`, `addressSet`).

Column `address` · JSON hex string · never null

**topic0** `FixedSizeBinary(32)`

Event selector: `keccak256` of the event signature (or the first indexed argument of an anonymous event). **Filterable**.

Column `topic0` · JSON hex string · can be null

**topic1** `FixedSizeBinary(32)`

First indexed argument, 32 bytes (addresses are left-padded). **Filterable**.

Column `topic1` · JSON hex string · can be null

**topic2** `FixedSizeBinary(32)`

Second indexed argument. **Filterable**.

Column `topic2` · JSON hex string · can be null

**topic3** `FixedSizeBinary(32)`

Third indexed argument. **Filterable**.

Column `topic3` · JSON hex string · can be null

**data** `Binary`

Non-indexed arguments, ABI-encoded. Empty (`0x`) when there are none.

Column `data` · JSON hex string · never null

**blockTimestamp** `UInt64`

Timestamp of the block (Unix seconds), on every log.

Column `block_timestamp` · JSON number · can be null

## Availability per chain

Which of these a chain fills is on its [chain page](https://docs.bloklake.com/chains/overview.md) and in [`GET /v1/schema`](https://docs.bloklake.com/api-reference/schema).


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