Ethereum Data Model

The sf.ethereum.type.v2.Block Protobuf is shared across EVM-compatible blockchains (Ethereum, Polygon, Arbitrum...). While the Protobuf definition (.proto file) is largely self-documented, it is important to be aware of the version of the Protobuf you are working with.

The Protobuf Version

Most changes in EVM chains are backward-compatible, meaning there is no need to introduce an entirely new Protobuf namespace (e.g., sf.ethereum.type.v3.Block). Instead, sf.ethereum.type.v2.Block is used consistently to avoid breaking changes.

To manage internal updates, Firehose uses a versioning system defined by the ver field in the Block Protobuf.

// Ver represents that data model version of the block, it is used internally by Firehose on Ethereum
// as a validation that we are reading the correct version.
int32 ver = 1;

This version refers to the Block emitted by the Firehose trace.

Version 3

• This version is current in place for all EVM chains, with the exception of Optimism from block 0 to the last pre-Prague (blockchains currently in Prague version are listed in a section later in this document) hard fork block.

• This version contains several known issues, which are described in the Protobuf definition itself (next to the corresponding field affected). You can also check out this GitHub issue.

Version 4

• This version is currently in place for the following chains:

  • Optimism

  • Ethereum Hoodi

  • Sei EVM

• This version fixes the known issue of version 3.

Prague-enabled blockchains

The following chains have already upgraded to Ethereum's Prague version:

• Ethereum Sepolia

• Ethereum Holesky

• BSC Mainnet

• BSC Testnet