Go-eth-consensus 
Go-eth-consensus is a suite of Go utilities to interact with the Ethereum consensus layer.
The core of this library was initially part of eth2-validator. However, as other projects started to mature, it became necessary to create a unified library to reduce code duplication and increase consistency.
Features
Consensus data types. Full set of data types (up to Bellatrix) in structs.go at root. It includes the SSZ encoding for each one using fastssz. Each type is end-to-end tested with the official consensus spec tests.
Http client. Lightweight implementation for the Beacon and Builder OpenAPI spec. For usage and examples see the Godoc. The endpoints are tested against a real server that mocks the OpenAPI spec.
Chaintime. Simple utilities to interact with slot times and epochs.
BLS. Abstraction to sign, recover and store (with keystore format) BLS keys. It includes two implementations: blst with cgo and kilic/bls12-381 with pure Go. The build flag CGO_ENABLED determines which library is used.
Installation
$ go get github.com/umbracle/go-eth-consensus
Bls benchmark
Benchmark for both BLS implementations:
$ CGO_ENABLED=0 go test -v ./bls/... -run=XXX -bench=.
goos: linux
goarch: amd64
pkg: github.com/umbracle/go-eth-consensus/bls
cpu: Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz
BenchmarkBLS_Sign
BenchmarkBLS_Sign-4 2330 515495 ns/op 30192 B/op 282 allocs/op
BenchmarkBLS_Verify
BenchmarkBLS_Verify-4 814 1646769 ns/op 74048 B/op 190 allocs/op
PASS
ok github.com/umbracle/go-eth-consensus/bls 3.739s
$ CGO_ENABLED=1 go test -v ./bls/... -run=XXX -bench=.
goos: linux
goarch: amd64
pkg: github.com/umbracle/go-eth-consensus/bls
cpu: Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz
BenchmarkBLS_Sign
BenchmarkBLS_Sign-4 2833 431271 ns/op 480 B/op 2 allocs/op
BenchmarkBLS_Verify
BenchmarkBLS_Verify-4 1282 903174 ns/op 4545 B/op 15 allocs/op
PASS
ok github.com/umbracle/go-eth-consensus/bls 2.525s