Electrs v0.12.0 is Fast

Since I’ve moved to Paul Lamb’s Bitcoin Knots version based on Bitcoin Core 31.2, I was finally able to switch to the latest version of Electrs v0.12.0, and boy is the new indexing server noticeably faster. If unaware, there are different implementations of Electrum servers that are meant to service SPV wallets (phone or light wallets) that don’t have the entire Bitcoin blockchain or verifying all transactions on their own. These wallets do retain some privacy in giving address ranges to look up so they don’t remove all privacy, but still best to use with your own node. So an Electrum server creates it’s own index and interacts much more efficiently with an SPV wallet than having them do so directly with a Bitcoin node. Consequently, Electrs is written in Rust (not my favorite), but I’ve been using it for years, and I’ve lately gone to using Rustup for managing my Rust version for compiling the software myself. Another popular version I haven’t played with yet is Fulcrum, and we’re also waiting for a version that supports silent payments without being too resource intensive. So kudos to Roman Zeyde for the Electrs project and his new indexing system. And reindexing took about 7 hours on my Raspberry Pi 5.

v0.12.0

romanz released this Sep 13

  • Switch to bindex:
    • requires Bitcoin Core 31+
    • uses REST API server (-rest=1)
    • new index format – requires reindexing!
  • Fix server.features response format.
  • Update transaction.id_from_pos argument parsing for API compliance.
  • Add SECURITY.md.

https://github.com/romanz/electrs/blob/master/RELEASE-NOTES.md#0120-sep-13-2026

https://github.com/romanz/electrs

Logo

Electrum Server in Rust

An efficient re-implementation of Electrum Server, inspired by ElectrumX, Electrum Personal Server and bitcoincore-indexd.

The motivation behind this project is to enable a user to self host an Electrum server, with required hardware resources not much beyond those of a full node. The server indexes the entire Bitcoin blockchain, and the resulting index enables fast queries for any given user wallet, allowing the user to keep real-time track of balances and transaction history using the Electrum wallet. Since it runs on the user’s own machine, there is no need for the wallet to communicate with external Electrum servers, thus preserving the privacy of the user’s addresses and balances.

BTC Prague 2024 dev/hack/day slides are here: https://bit.ly/electrs

Usage

Please prefer to use OUR usage guide!

External guides can be out-of-date and have various problems. At least double-check that the guide you’re using is actively maintained. If you can’t use our guide, please ask about what you don’t understand or consider using automated deployments.

Note that this implementation of Electrum server is optimized for personal/small-scale (family/friends) usage. It’s a bad idea to run it publicly as it’d expose you to DoS and maybe also other attacks. If you want to run a public server you may be interested in the Blockstream fork of electrs which is better optimized for public usage at the cost of consuming significantly more resources.

Features

  • Supports Electrum protocol v1.4
  • Maintains an index over transaction inputs and outputs, allowing fast balance queries
  • Fast synchronization of the Bitcoin blockchain (~6.5 hours for ~504GB @ August 2023) using HDD storage.
  • Low index storage overhead (~10%), relying on a local full node for transaction retrieval
  • Efficient mempool tracker (allowing better fee estimation)
  • Low CPU & memory usage (after initial indexing)
  • txindex is not required for the Bitcoin node
  • Uses a single RocksDB database, for better consistency and crash recovery

Altcoins

Altcoins are not supported! Forks of Bitcoin codebase that relax the consensus rules (hard forks) are also not supported.

You may be able to find a fork of electrs that does support them, look around or make your own, just don’t file issues/PRs here.

Index database

The database schema is described here.

Contributing

All contributions to this project are welcome. Please refer to the Contributing Guidelines for more details.

Logo

Our logo is generously provided by Dominik Průša under the MIT license. Based on the Electrum logo and the Rust language logo.