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Beacon API

Nimbus exposes an extremely fast implementation of the standard Beacon API. The API allows you to use Nimbus together with third-party tooling such as validator clients, block explorers, as well as your own monitoring infrastructure.

The Beacon API is a REST interface accessed via http. If you wish to expose the beacon node to the public internet, it is recommended to use a proxy such as nginx to provide caching and SSL support.


If you are running validators with your beacon node, do not expose the REST API to the public internet or use the same beacon node for deep historical queries: doing so may negatively affect validator performance.

Test your tooling against our servers

The API is available from:


You can make requests as follows (here we are requesting the version the Nimbus software version of the node in question):

curl -X GET
curl -X GET
curl -X GET

The test endpoints are part of pre-release testing and run an unstable version of Nimbus. We welcome reports about any problems you might have with them.

They may also be unresponsive at times: please do not rely on them for validation. We may also disable them at any time without warning.

Configure your node to run a local REST server

By default, the REST interface is disabled. To enable it, start the beacon node with the --rest option:

./ --rest

Then access the API from http://localhost:5052/. For example, to get the version of the Nimbus software your node is running:

curl -X GET http://localhost:5052/eth/v1/node/version

By default, only connections from the same machine are entertained. The port and listening address can be further configured through the options --rest-port and --rest-address.


If you are using a validator client with a Nimbus beacon node, and running a Nimbus version prior to v1.5.5, then you will need to launch the node with the --subscribe-all-subnets option enabled (in addition to the --rest option).

Some useful commands

Standard endpoints

While these are all well documented in the official docs, here are a handful of simple examples to get you started:


Retrieve details of the chain's genesis which can be used to identify chain.

curl -X GET
curl -X GET http://localhost:5052/eth/v1/beacon/genesis

Deposit contract

Get deposit contract address (retrieve Eth1 deposit contract address and chain ID).

curl -X GET
curl -X GET http://localhost:5052/eth/v1/config/deposit_contract

Peer count

Get peer count:

curl -X GET
curl -X GET http://localhost:5052/eth/v1/node/peer_count

Syncing status

Get node syncing status (requests the beacon node to describe if it's currently syncing or not, and if it is, what block it is up to)

curl -X GET
curl -X GET http://localhost:5052/eth/v1/node/syncing

Fork schedule

Get scheduled upcoming forks (retrieve all forks, past present and future, of which this node is aware)

curl -X GET
curl -X GET http://localhost:5052/eth/v1/config/fork_schedule

Nimbus specific endpoints

In addition to supporting the standard endpoints, Nimbus has a set of specific endpoints which augment the standard API.

Check Graffiti String

curl -X GET
curl -X GET http://localhost:5052/nimbus/v1/graffiti

Set Graffiti String

curl -X POST http://localhost:5052/nimbus/v1/graffiti -H  "Content-Type: text/plain" -d "new graffiti"

Set Log Level



  • The complete API specification is well documented here

  • See the repository Readme here