client

README

go-eth2-client

Go library providing an abstraction to multiple Ethereum 2 beacon nodes. Its external API follows the official Ethereum beacon APIs specification.

This library is under development; expect APIs and data structures to change until it reaches version 1.0. In addition, clients' implementations of both their own and the standard API are themselves under development so implementation of the the full API can be incomplete.

Table of Contents

• Install
• Usage
• Maintainers
• Contribute
• License

Install

go-eth2-client is a standard Go module which can be installed with:

go get github.com/attestantio/go-eth2-client

Support

go-eth2-client supports beacon nodes that comply with the standard beacon node API. To date it has been tested against the following beacon nodes:

• Lighthouse minimum version 2.0.0
• Nimbus minimum version 1.7.0
• Prysm minimum version ?
• Teku minimum version 21.9.2

Usage

Please read the Go documentation for this library for interface information.

Example

Below is a complete annotated example to access a beacon node.

package main

import (
    "context"
    "fmt"
    
    eth2client "github.com/attestantio/go-eth2-client"
    "github.com/attestantio/go-eth2-client/http"
    "github.com/rs/zerolog"
)

func main() {
    // Provide a cancellable context to the creation function.
    ctx, cancel := context.WithCancel(context.Background())
    client, err := http.New(ctx,
        // WithAddress supplies the address of the beacon node, as a URL.
        http.WithAddress("http://localhost:5052/"),
        // LogLevel supplies the level of logging to carry out.
        http.WithLogLevel(zerolog.WarnLevel),
    )
    if err != nil {
        panic(err)
    }
    
    fmt.Printf("Connected to %s\n", client.Name())
    
    // Client functions have their own interfaces.  Not all functions are
    // supported by all clients, so checks should be made for each function when
    // casting the service to the relevant interface.
    if provider, isProvider := client.(eth2client.GenesisProvider); isProvider {
        genesis, err := provider.Genesis(ctx)
        if err != nil {
            panic(err)
        }
        fmt.Printf("Genesis time is %v\n", genesis.GenesisTime)
    }

    // You can also access the struct directly if required.
    httpClient := client.(*http.Service)
    genesis, err := httpClient.Genesis(ctx)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Genesis validators root is %#x\n", genesis.GenesisValidatorsRoot)

    // Cancelling the context passed to New() frees up resources held by the
    // client, closes connections, clears handlers, etc.
    cancel()
}

Maintainers

Jim McDonald: @mcdee.

Contribute

Contributions welcome. Please check out the issues.

License

Apache-2.0 © 2020, 2021 Attestant Limited

Documentation

Index

• type AggregateAttestationProvider
• type AggregateAttestationsSubmitter
• type AttestationDataProvider
• type AttestationPoolProvider
• type AttestationsSubmitter
• type AttesterDutiesProvider
• type BLSToExecutionChangesSubmitter
• type BeaconBlockHeadersProvider
• type BeaconBlockProposalProvider
• type BeaconBlockRootProvider
• type BeaconBlockSubmitter
• type BeaconCommitteeSubscriptionsSubmitter
• type BeaconCommitteesProvider
• type BeaconStateProvider
• type BeaconStateRandaoProvider
• type BeaconStateRootProvider
• type BlindedBeaconBlockProposalProvider
• type BlindedBeaconBlockSubmitter
• type DepositContractProvider
• type DomainProvider
• type EpochFromStateIDProvider
• type EventHandlerFunc
• type EventsProvider
• type FarFutureEpochProvider
• type FinalityProvider
• type ForkProvider
• type ForkScheduleProvider
• type GenesisProvider
• type GenesisTimeProvider
• type GenesisValidatorsRootProvider
• type NodeClientProvider
• type NodeSyncingProvider
• type NodeVersionProvider
• type ProposalPreparationsSubmitter
• type ProposerDutiesProvider
• type Service
• type SignedBeaconBlockProvider
• type SlotDurationProvider
• type SlotFromStateIDProvider
• type SlotsPerEpochProvider
• type SpecProvider
• type SyncCommitteeContributionProvider
• type SyncCommitteeContributionsSubmitter
• type SyncCommitteeDutiesProvider
• type SyncCommitteeMessagesSubmitter
• type SyncCommitteeSubscriptionsSubmitter
• type SyncCommitteesProvider
• type SyncStateProvider
• type TargetAggregatorsPerCommitteeProvider
• type ValidatorBalancesProvider
• type ValidatorIDProvider
• type ValidatorIndexProvider
• type ValidatorPubKeyProvider
• type ValidatorRegistrationsSubmitter
• type ValidatorsProvider
• type VoluntaryExitSubmitter

Types

type AggregateAttestationProvider

type AggregateAttestationProvider interface {
	// AggregateAttestation fetches the aggregate attestation given an attestation.
	AggregateAttestation(ctx context.Context, slot phase0.Slot, attestationDataRoot phase0.Root) (*phase0.Attestation, error)
}

AggregateAttestationProvider is the interface for providing aggregate attestations.

type AggregateAttestationsSubmitter

type AggregateAttestationsSubmitter interface {
	// SubmitAggregateAttestations submits aggregate attestations.
	SubmitAggregateAttestations(ctx context.Context, aggregateAndProofs []*phase0.SignedAggregateAndProof) error
}

AggregateAttestationsSubmitter is the interface for submitting aggregate attestations.

type AttestationDataProvider

type AttestationDataProvider interface {
	// AttestationData fetches the attestation data for the given slot and committee index.
	AttestationData(ctx context.Context, slot phase0.Slot, committeeIndex phase0.CommitteeIndex) (*phase0.AttestationData, error)
}

AttestationDataProvider is the interface for providing attestation data.

type AttestationPoolProvider

type AttestationPoolProvider interface {
	// AttestationPool fetches the attestation pool for the given slot.
	AttestationPool(ctx context.Context, slot phase0.Slot) ([]*phase0.Attestation, error)
}

AttestationPoolProvider is the interface for providing attestation pools.

type AttestationsSubmitter

type AttestationsSubmitter interface {
	// SubmitAttestations submits attestations.
	SubmitAttestations(ctx context.Context, attestations []*phase0.Attestation) error
}

AttestationsSubmitter is the interface for submitting attestations.

type AttesterDutiesProvider

type AttesterDutiesProvider interface {
	// AttesterDuties obtains attester duties.
	// If validatorIndicess is nil it will return all duties for the given epoch.
	AttesterDuties(ctx context.Context, epoch phase0.Epoch, validatorIndices []phase0.ValidatorIndex) ([]*apiv1.AttesterDuty, error)
}

AttesterDutiesProvider is the interface for providing attester duties

type BLSToExecutionChangesSubmitter

type BLSToExecutionChangesSubmitter interface {
	// SubmitBLSToExecutionChanges submits BLS to execution address change operations.
	SubmitBLSToExecutionChanges(ctx context.Context, blsToExecutionChanges []*capella.SignedBLSToExecutionChange) error
}

BLSToExecutionChangesSubmitter is the interface for submitting BLS to execution address changes.

type BeaconBlockHeadersProvider

type BeaconBlockHeadersProvider interface {
	// BeaconBlockHeader provides the block header of a given block ID.
	BeaconBlockHeader(ctx context.Context, blockID string) (*apiv1.BeaconBlockHeader, error)
}

BeaconBlockHeadersProvider is the interface for providing beacon block headers.

type BeaconBlockProposalProvider

type BeaconBlockProposalProvider interface {
	// BeaconBlockProposal fetches a proposed beacon block for signing.
	BeaconBlockProposal(ctx context.Context, slot phase0.Slot, randaoReveal phase0.BLSSignature, graffiti []byte) (*spec.VersionedBeaconBlock, error)
}

BeaconBlockProposalProvider is the interface for providing beacon block proposals.

type BeaconBlockRootProvider

type BeaconBlockRootProvider interface {
	// BeaconBlockRoot fetches a block's root given a block ID.
	BeaconBlockRoot(ctx context.Context, blockID string) (*phase0.Root, error)
}

BeaconBlockRootProvider is the interface for providing beacon block roots.

type BeaconBlockSubmitter

type BeaconBlockSubmitter interface {
	// SubmitBeaconBlock submits a beacon block.
	SubmitBeaconBlock(ctx context.Context, block *spec.VersionedSignedBeaconBlock) error
}

BeaconBlockSubmitter is the interface for submitting beacon blocks.

type BeaconCommitteeSubscriptionsSubmitter

type BeaconCommitteeSubscriptionsSubmitter interface {
	// SubmitBeaconCommitteeSubscriptions subscribes to beacon committees.
	SubmitBeaconCommitteeSubscriptions(ctx context.Context, subscriptions []*apiv1.BeaconCommitteeSubscription) error
}

BeaconCommitteeSubscriptionsSubmitter is the interface for submitting beacon committee subnet subscription requests.

type BeaconCommitteesProvider

type BeaconCommitteesProvider interface {
	// BeaconCommittees fetches all beacon committees for the epoch at the given state.
	BeaconCommittees(ctx context.Context, stateID string) ([]*apiv1.BeaconCommittee, error)

	// BeaconCommitteesAtEpoch fetches all beacon committees for the given epoch at the given state.
	BeaconCommitteesAtEpoch(ctx context.Context, stateID string, epoch phase0.Epoch) ([]*apiv1.BeaconCommittee, error)
}

BeaconCommitteesProvider is the interface for providing beacon committees.

type BeaconStateProvider

type BeaconStateProvider interface {
	// BeaconState fetches a beacon state given a state ID.
	BeaconState(ctx context.Context, stateID string) (*spec.VersionedBeaconState, error)
}

BeaconStateProvider is the interface for providing beacon state.

type BeaconStateRandaoProvider

type BeaconStateRandaoProvider interface {
	// BeaconStateRandao fetches a beacon state RANDAO given a state ID.
	BeaconStateRandao(ctx context.Context, stateID string) (*phase0.Root, error)
}

BeaconStateRandaoProvider is the interface for providing beacon state RANDAOs.

type BeaconStateRootProvider

type BeaconStateRootProvider interface {
	// BeaconStateRoot fetches a beacon state root given a state ID.
	BeaconStateRoot(ctx context.Context, stateID string) (*phase0.Root, error)
}

BeaconStateRootProvider is the interface for providing beacon state roots.

type BlindedBeaconBlockProposalProvider

type BlindedBeaconBlockProposalProvider interface {
	// BlindedBeaconBlockProposal fetches a blinded proposed beacon block for signing.
	BlindedBeaconBlockProposal(ctx context.Context, slot phase0.Slot, randaoReveal phase0.BLSSignature, graffiti []byte) (*api.VersionedBlindedBeaconBlock, error)
}

BlindedBeaconBlockProposalProvider is the interface for providing blinded beacon block proposals.

type BlindedBeaconBlockSubmitter

type BlindedBeaconBlockSubmitter interface {
	// SubmitBlindedBeaconBlock submits a beacon block.
	SubmitBlindedBeaconBlock(ctx context.Context, block *api.VersionedSignedBlindedBeaconBlock) error
}

BlindedBeaconBlockSubmitter is the interface for submitting blinded beacon blocks.

type DepositContractProvider

type DepositContractProvider interface {
	// DepositContract provides details of the Ethereum 1 deposit contract for the chain.
	DepositContract(ctx context.Context) (*apiv1.DepositContract, error)
}

DepositContractProvider is the interface for providng details about the deposit contract.

type DomainProvider

type DomainProvider interface {
	// Domain provides a domain for a given domain type at a given epoch.
	Domain(ctx context.Context, domainType phase0.DomainType, epoch phase0.Epoch) (phase0.Domain, error)

	// GenesisDomain returns the domain for the given domain type at genesis.
	// N.B. this is not always the same as the the domain at epoch 0.  It is possible
	// for a chain's fork schedule to have multiple forks at genesis.  In this situation,
	// GenesisDomain() will return the first, and Domain() will return the last.
	GenesisDomain(ctx context.Context, domainType phase0.DomainType) (phase0.Domain, error)
}

DomainProvider provides a domain for a given domain type at an epoch.

type EpochFromStateIDProvider

type EpochFromStateIDProvider interface {
	// EpochFromStateID converts a state ID to its epoch.
	EpochFromStateID(ctx context.Context, stateID string) (phase0.Epoch, error)
}

EpochFromStateIDProvider is the interface for providing epochs from state IDs.

type EventHandlerFunc

type EventHandlerFunc func(*apiv1.Event)

EventHandlerFunc is the handler for events.

type EventsProvider

type EventsProvider interface {
	// Events feeds requested events with the given topics to the supplied handler.
	Events(ctx context.Context, topics []string, handler EventHandlerFunc) error
}

EventsProvider is the interface for providing events.

type FarFutureEpochProvider

type FarFutureEpochProvider interface {
	// FarFutureEpoch provides the far future epoch of the chain.
	FarFutureEpoch(ctx context.Context) (phase0.Epoch, error)
}

FarFutureEpochProvider is the interface for providing the far future epoch of a chain.

type FinalityProvider

type FinalityProvider interface {
	// Finality provides the finality given a state ID.
	Finality(ctx context.Context, stateID string) (*apiv1.Finality, error)
}

FinalityProvider is the interface for providing finality information.

type ForkProvider

type ForkProvider interface {
	// Fork fetches fork information for the given state.
	Fork(ctx context.Context, stateID string) (*phase0.Fork, error)
}

ForkProvider is the interface for providing fork information.

type ForkScheduleProvider

type ForkScheduleProvider interface {
	// ForkSchedule provides details of past and future changes in the chain's fork version.
	ForkSchedule(ctx context.Context) ([]*phase0.Fork, error)
}

ForkScheduleProvider is the interface for providing fork schedule data.

type GenesisProvider

type GenesisProvider interface {
	// Genesis fetches genesis information for the chain.
	Genesis(ctx context.Context) (*apiv1.Genesis, error)
}

GenesisProvider is the interface for providing genesis information.

type GenesisTimeProvider

type GenesisTimeProvider interface {
	// GenesisTime provides the genesis time of the chain.
	GenesisTime(ctx context.Context) (time.Time, error)
}

GenesisTimeProvider is the interface for providing the genesis time of a chain.

type GenesisValidatorsRootProvider

type GenesisValidatorsRootProvider interface {
	// GenesisValidatorsRoot provides the genesis validators root of the chain.
	GenesisValidatorsRoot(ctx context.Context) ([]byte, error)
}

GenesisValidatorsRootProvider is the interface for providing the genesis validators root of a chain.

type NodeClientProvider

type NodeClientProvider interface {
	// NodeClient provides the client for the node.
	NodeClient(ctx context.Context) (string, error)
}

NodeClientProvider provides the client for the node.

type NodeSyncingProvider

type NodeSyncingProvider interface {
	// NodeSyncing provides the state of the node's synchronization with the chain.
	NodeSyncing(ctx context.Context) (*apiv1.SyncState, error)
}

NodeSyncingProvider is the interface for providing synchronization state.

type NodeVersionProvider

type NodeVersionProvider interface {
	// NodeVersion returns a free-text string with the node version.
	NodeVersion(ctx context.Context) (string, error)
}

NodeVersionProvider is the interface for providing the node version.

type ProposalPreparationsSubmitter

type ProposalPreparationsSubmitter interface {
	// SubmitProposalPreparations provides the beacon node with information required if a proposal for the given validators
	// shows up in the next epoch.
	SubmitProposalPreparations(ctx context.Context, preparations []*apiv1.ProposalPreparation) error
}

ProposalPreparationsSubmitter is the interface for submitting proposal preparations.

type ProposerDutiesProvider

type ProposerDutiesProvider interface {
	// ProposerDuties obtains proposer duties for the given epoch.
	// If validatorIndices is empty all duties are returned, otherwise only matching duties are returned.
	ProposerDuties(ctx context.Context, epoch phase0.Epoch, validatorIndices []phase0.ValidatorIndex) ([]*apiv1.ProposerDuty, error)
}

ProposerDutiesProvider is the interface for providing proposer duties.

type Service

type Service interface {
	// Name returns the name of the client implementation.
	Name() string

	// Address returns the address of the client.
	Address() string
}

Service is the service providing a connection to an Ethereum 2 client.

type SignedBeaconBlockProvider

type SignedBeaconBlockProvider interface {
	// SignedBeaconBlock fetches a signed beacon block given a block ID.
	SignedBeaconBlock(ctx context.Context, blockID string) (*spec.VersionedSignedBeaconBlock, error)
}

SignedBeaconBlockProvider is the interface for providing beacon blocks.

type SlotDurationProvider

type SlotDurationProvider interface {
	// SlotDuration provides the duration of a slot of the chain.
	SlotDuration(ctx context.Context) (time.Duration, error)
}

SlotDurationProvider is the interface for providing the duration of each slot of a chain.

type SlotFromStateIDProvider

type SlotFromStateIDProvider interface {
	// SlotFromStateID converts a state ID to its slot.
	SlotFromStateID(ctx context.Context, stateID string) (phase0.Slot, error)
}

SlotFromStateIDProvider is the interface for providing slots from state IDs.

type SlotsPerEpochProvider

type SlotsPerEpochProvider interface {
	// SlotsPerEpoch provides the slots per epoch of the chain.
	SlotsPerEpoch(ctx context.Context) (uint64, error)
}

SlotsPerEpochProvider is the interface for providing the number of slots in each epoch of a chain.

type SpecProvider

type SpecProvider interface {
	// Spec provides the spec information of the chain.
	Spec(ctx context.Context) (map[string]interface{}, error)
}

SpecProvider is the interface for providing spec data.

type SyncCommitteeContributionProvider

type SyncCommitteeContributionProvider interface {
	// SyncCommitteeContribution provides a sync committee contribution.
	SyncCommitteeContribution(ctx context.Context, slot phase0.Slot, subcommitteeIndex uint64, beaconBlockRoot phase0.Root) (*altair.SyncCommitteeContribution, error)
}

SyncCommitteeContributionProvider is the interface for providing sync committee contributions.

type SyncCommitteeContributionsSubmitter

type SyncCommitteeContributionsSubmitter interface {
	// SubmitSyncCommitteeContributions submits sync committee contributions.
	SubmitSyncCommitteeContributions(ctx context.Context, contributionAndProofs []*altair.SignedContributionAndProof) error
}

SyncCommitteeContributionsSubmitter is the interface for submitting sync committee contributions.

type SyncCommitteeDutiesProvider

type SyncCommitteeDutiesProvider interface {
	// SyncCommitteeDuties obtains sync committee duties.
	// If validatorIndicess is nil it will return all duties for the given epoch.
	SyncCommitteeDuties(ctx context.Context, epoch phase0.Epoch, validatorIndices []phase0.ValidatorIndex) ([]*apiv1.SyncCommitteeDuty, error)
}

SyncCommitteeDutiesProvider is the interface for providing sync committee duties.

type SyncCommitteeMessagesSubmitter

type SyncCommitteeMessagesSubmitter interface {
	// SubmitSyncCommitteeMessages submits sync committee messages.
	SubmitSyncCommitteeMessages(ctx context.Context, messages []*altair.SyncCommitteeMessage) error
}

SyncCommitteeMessagesSubmitter is the interface for submitting sync committee messages.

type SyncCommitteeSubscriptionsSubmitter

type SyncCommitteeSubscriptionsSubmitter interface {
	// SubmitSyncCommitteeSubscriptions subscribes to sync committees.
	SubmitSyncCommitteeSubscriptions(ctx context.Context, subscriptions []*apiv1.SyncCommitteeSubscription) error
}

SyncCommitteeSubscriptionsSubmitter is the interface for submitting sync committee subnet subscription requests.

type SyncCommitteesProvider

type SyncCommitteesProvider interface {
	// SyncCommittee fetches the sync committee for the given state.
	SyncCommittee(ctx context.Context, stateID string) (*apiv1.SyncCommittee, error)

	// SyncCommitteeAtEpoch fetches the sync committee for the given epoch at the given state.
	SyncCommitteeAtEpoch(ctx context.Context, stateID string, epoch phase0.Epoch) (*apiv1.SyncCommittee, error)
}

SyncCommitteesProvider is the interface for providing sync committees.

type SyncStateProvider

type SyncStateProvider interface {
	// SyncState provides the state of the node's synchronization with the chain.
	SyncState(ctx context.Context) (*apiv1.SyncState, error)
}

SyncStateProvider is the interface for providing synchronization state.

type TargetAggregatorsPerCommitteeProvider

type TargetAggregatorsPerCommitteeProvider interface {
	// TargetAggregatorsPerCommittee provides the target number of aggregators for each attestation committee.
	TargetAggregatorsPerCommittee(ctx context.Context) (uint64, error)
}

TargetAggregatorsPerCommitteeProvider is the interface for providing the target number of aggregators in each attestation committee.

type ValidatorBalancesProvider

type ValidatorBalancesProvider interface {
	// ValidatorBalances provides the validator balances for a given state.
	// stateID can be a slot number or state root, or one of the special values "genesis", "head", "justified" or "finalized".
	// validatorIndices is a list of validator indices to restrict the returned values.  If no validators are supplied no filter
	// will be applied.
	ValidatorBalances(ctx context.Context, stateID string, validatorIndices []phase0.ValidatorIndex) (map[phase0.ValidatorIndex]phase0.Gwei, error)
}

ValidatorBalancesProvider is the interface for providing validator balances.

type ValidatorIDProvider

type ValidatorIDProvider interface {
	ValidatorIndexProvider
	ValidatorPubKeyProvider
}

ValidatorIDProvider is the interface that provides the identifiers (pubkey, index) of a validator.

type ValidatorIndexProvider

type ValidatorIndexProvider interface {
	// Index provides the index of the validator.
	Index(ctx context.Context) (phase0.ValidatorIndex, error)
}

ValidatorIndexProvider is the interface for entities that can provide the index of a validator.

type ValidatorPubKeyProvider

type ValidatorPubKeyProvider interface {
	// PubKey provides the public key of the validator.
	PubKey(ctx context.Context) (phase0.BLSPubKey, error)
}

ValidatorPubKeyProvider is the interface for entities that can provide the public key of a validator.

type ValidatorRegistrationsSubmitter

type ValidatorRegistrationsSubmitter interface {
	// SubmitValidatorRegistrations submits a validator registration.
	SubmitValidatorRegistrations(ctx context.Context, registrations []*api.VersionedSignedValidatorRegistration) error
}

ValidatorRegistrationsSubmitter is the interface for submitting validator registrations.

type ValidatorsProvider

type ValidatorsProvider interface {
	// Validators provides the validators, with their balance and status, for a given state.
	// stateID can be a slot number or state root, or one of the special values "genesis", "head", "justified" or "finalized".
	// validatorIndices is a list of validator indices to restrict the returned values.  If no validators IDs are supplied no filter
	// will be applied.
	Validators(ctx context.Context, stateID string, validatorIndices []phase0.ValidatorIndex) (map[phase0.ValidatorIndex]*apiv1.Validator, error)

	// ValidatorsByPubKey provides the validators, with their balance and status, for a given state.
	// stateID can be a slot number or state root, or one of the special values "genesis", "head", "justified" or "finalized".
	// validatorPubKeys is a list of validator public keys to restrict the returned values.  If no validators public keys are
	// supplied no filter will be applied.
	ValidatorsByPubKey(ctx context.Context, stateID string, validatorPubKeys []phase0.BLSPubKey) (map[phase0.ValidatorIndex]*apiv1.Validator, error)
}

ValidatorsProvider is the interface for providing validator information.

type VoluntaryExitSubmitter

type VoluntaryExitSubmitter interface {
	// SubmitVoluntaryExit submits a voluntary exit.
	SubmitVoluntaryExit(ctx context.Context, voluntaryExit *phase0.SignedVoluntaryExit) error
}

VoluntaryExitSubmitter is the interface for submitting voluntary exits.