# README

ethsigdb

Ethereum transaction log event signature database and Go lookup library.

To purpose of this dataset is to do a reverse lookup to convert an Ethereum transaction log topicHash to the event defintion.

For example, when an ERC20 transfer transaction is mined, it will emit the event log with topics[0] value of: 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef

In order to look up from 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef what is the actual event definition, we use this library and database to return: Transfer(address,address,uint256).

This is useful when converting event data to human readable formats, or for decoding an event.

Dataset

The signature dataset was originally sourced from https://github.com/otterscan/topic0 which in turn is sourced from https://github.com/ethereum/sourcify.

NOTE: the contents are stored in ./ethsigdb.json with ~9000 entries. This is a pretty small dataset, but you could certainly extend this library to use other datasets/backends.

Additionally, we have ./cmd/build-dataset/more_events.go with a list of event signatures which you can add to. When running the build-dataset program, it will compute the topic hashes and store all datasets into ./ethsigdb.json.

Finally, if you'd like to search for events by topic hash, you can use ./cmd/find-topics which will use the remote openchain.xyz service to look up events by their topic hash, and them print any topic hashes which are not in our local database, so you can copy them over to ./cmd/build-dataset/more_events.go and rebuild the local db.

Example

sigdb := ethsigdb.Default()

// Lookup event signature
topicHash := "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"

event, ok := sigdb.Lookup(topicHash)
if !ok {
  log.Fatal("event not found")
}

// this will return Transfer(address,address,uint256)
fmt.Println("found event!", event)