This is an Ethereum block explorer designed to be run locally with an archive node companion, more specifically, with [Erigon](https://github.com/ledgerwatch/erigon).
This approach brings many advantages, as follows.
### Privacy
You are querying your own node, so you are not sending your IP address or queries to an external third-party node.
### Fast
Since you are querying your local archive node, everything is fast, no network roundtrips are necessary.
### Actually, very fast
This software was designed to be a companion of Erigon, a blazingly fast archive node.
### Really, it is even faster
The standard web3 jsonrpc methods are quite verbose and generic requiring many calls to gather many pieces of information at client side.
We've implemented some custom methods at rpcdaemon level, less information is needed to be json-marshalled and transmitted over network.
Current offerings are either closed source or lack many features the most famous Ethereum block explorer has, or simply have high requirements like having an archive node + additional indexers.
Otterscan requires only mainline Erigon executing node, patched Erigon RPC daemon and running Otterscan itself (a simple React app), which makes it a laptop-friendly block explorer.
- It is heavily based on Erigon, whose mascot is an otter (Erigon, the otter), think about an otter scanning your transactions inside blocks.
- It is an homage to the most famous and used ethereum block explorer.
- The author loves wordplays and bad puns.
## It looks familiar...
The UI was intentionally made very similar to the most popular Ethereum block explorer so users do not strugle trying to find where the information is.
However, you will see that we made many UI improvements.
We implemented new JSON-RPC APIs to expose information not available in a standard ETH node. They can be useful for non-Otterscan users and their specification is available [here](./docs/custom-jsonrpc.md).
To the [Erigon](https://github.com/ledgerwatch/erigon) team that made it possible for regular humans to run an archive node in a retail laptop. Also, they have been very helpful explaining Erigon's internals which made the modifications Otterscan requires possible.
To the owners of the [4bytes repository](https://github.com/ethereum-lists/4bytes) that we import and use to translate the method selectors to human-friendly strings.
To [Ethers](https://github.com/ethers-io/ethers.js/) which is the client library we used to interact with the ETH node. It is high level enough to hide most jsonrpc particularities, but flexible enough to allow easy interaction with custom jsonrpc methods.
Erigon keeps evolving at a fast pace, with weekly releases, sometimes with (necessary) breaking changes.
This project intends to keep following their progress and mantaining compatibility as the availability of the author permits.
Erigon itself is alpha, so I consider this software is also in alpha state, however it is pretty usable.
Also there is room for many improvements that are not possible in the current centralized, closed source block explorer offerings and the author of this software would like to have.
