# EraE Format Quickstart EraE supersedes [Era1](https://github.com/eth-clients/e2store-format-specs/blob/master/formats/era1.md) as the EL history archive format and is capable of encoding pre-merge, transition, and post-merge epochs in a single format. EraE files will be generated for the entire chain history, replacing Era1 for most purposes. Both formats use the same [e2store](https://github.com/eth-clients/e2store-format-specs) container and share most entry types. The key differences in eraE are: - **Grouped layout**: Era1 interleaves entries per block (`header₀ body₀ receipts₀ td₀ header₁ body₁ ...`). EraE groups entries by type (`header₀ header₁ ... body₀ body₁ ... receipts₀ receipts₁ ...`). - **Slim receipts** (type `0x0a`) instead of legacy compressed receipts (type `0x05`). These use the eth/69 encoding: `[tx-type, post-state-or-status, cumulative-gas-used, [logs...]]`, which exclude the bloom filter. - **ComponentIndex** (type `0x3267`) instead of Era1's BlockIndex, enabling variable numbers of components per block (e.g. TotalDifficulty is omitted post-merge). - **No Accumulator or TotalDifficulty** for pure post-merge epochs. Transition epochs (spanning the merge) include both. An eraE file holds up to 8192 blocks. Files are named `<network>-<epoch>-<hash>.erae`, where `<hash>` is the first 4 bytes (hex) of the last block hash in the epoch. Each archive directory includes a `checksums.txt` with per-file SHA-256 hashes. ## Links - **Full specification**: https://github.com/eth-clients/e2store-format-specs/pull/16 - **Mainnet & Sepolia exports**: https://ethpandaops.io/data/history/ - **Geth implementation**: https://github.com/ethereum/go-ethereum/pull/32157 - **Nimbus implementation**: https://github.com/status-im/nimbus-eth1/pull/3979