5.0 KiB
go-ens
Go module to simplify interacting with the Ethereum Name Service contracts.
Table of Contents
Install
go-ens
is a standard Go module which can be installed with:
go get github.com/wealdtech/go-ens
Usage
go-ens
provides simple access to the Ethereum Name Service (ENS) contracts.
Resolution
The most commonly-used feature of ENS is resolution: converting an ENS name to an Ethereum address. go-ens
provides a simple call to allow this:
address, err := ens.Resolve(client, domain)
where client
is a connection to an Ethereum client and domain
is the fully-qualified name you wish to resolve (e.g. foo.mydomain.eth
) (full examples for using this are given in the Example section below).
The reverse process, converting an address to an ENS name, is just as simple:
domain, err := ens.ReverseResolve(client, address)
Note that if the address does not have a reverse resolution this will return "". If you just want a string version of an address for on-screen display then you can use ens.Format()
, for example:
fmt.Printf("The address is %s\n", ens.Format(client, address))
This will carry out reverse resolution of the address and print the name if present; if not it will print a formatted version of the address.
Management of names
A top-level name is one that sits directly underneath .eth
, for example mydomain.eth
. Lower-level names, such as foo.mydomain.eth
are covered in the following section. go-ens
provides a simplified Name
interface to manage top-level, removing the requirement to understand registrars, controllers, etc.
Starting out with names in go-ens
is easy:
client, err := ethclient.Dial("https://infura.io/v3/SECRET")
name, err := ens.NewName(client, "mydomain.eth")
Addresses can be set and obtained using the address functions, for example to get an address:
COIN_TYPE_ETHEREUM := uint64(60)
address, err := name.Address(COIN_TYPE_ETHEREUM)
ENS supports addresses for multiple coin types; values of coin types can be found at https://github.com/satoshilabs/slips/blob/master/slip-0044.md
Registering and extending names
Most operations on a domain will involve setting resolvers and resolver information.
Management of subdomains
Because subdomains have their own registrars they do not work with the Name
interface.
Example
package main
import (
"fmt"
"github.com/ethereum/go-ethereum/ethclient"
ens "github.com/wealdtech/go-ens/v3"
)
func main() {
// Replace SECRET with your own access token for this example to work.
client, err := ethclient.Dial("https://mainnet.infura.io/v3/SECRET")
if err != nil {
panic(err)
}
// Resolve a name to an address
domain := "avsa.eth"
address, err := ens.Resolve(client, domain)
if err != nil {
panic(err)
}
fmt.Printf("Address of %s is %s\n", domain, address.Hex())
// Reverse resolve an address to a name
reverse, err := ens.ReverseResolve(client, address)
if err != nil {
panic(err)
}
if reverse == "" {
fmt.Printf("%s has no reverse lookup\n", address.Hex())
} else {
fmt.Printf("Name of %s is %s\n", address.Hex(), reverse)
}
}
package main
import (
"github.com/ethereum/go-ethereum/ethclient"
ens "github.com/wealdtech/go-ens/v3"
)
func main() {
client, err := ethclient.Dial("https://mainnet.infura.io/v3/SECRET")
if err != nil {
panic(err)
}
// Resolve a name to an address
domain := "wealdtech.eth"
address, err := ens.Resolve(client, domain)
if err != nil {
panic(err)
}
fmt.Printf("Address of %s is %s\n", domain, address.Hex())
// Reverse resolve an address to a name
reverse, err := ens.ReverseResolve(client, address)
if err != nil {
panic(err)
}
if reverse == "" {
fmt.Printf("%s has no reverse lookup\n", address.Hex())
} else {
fmt.Printf("Name of %s is %s\n", address.Hex(), reverse)
}
}
Maintainers
Jim McDonald: @mcdee.
Contribute
Contributions welcome. Please check out the issues.
License
Apache-2.0 © 2019 Weald Technology Trading Ltd