Chainlink expands the capabilities of smart contracts by enabling access to real-world data and off-chain computation while maintaining the security and reliability guarantees inherent to blockchain technology.

This repo contains the Chainlink core node and contracts. The core node is the bundled binary available to be run by node operators participating in a decentralized oracle network. All major release versions have pre-built docker images available for download from the Chainlink dockerhub. If you are interested in contributing please see our contribution guidelines. If you are here to report a bug or request a feature, please check currently open Issues. For more information about how to get started with Chainlink, check our official documentation.

Community

Chainlink has an active and ever growing community. Discord is the primary communication channel used for day to day communication, answering development questions, and aggregating Chainlink related content. Take a look at the community docs for more information regarding Chainlink social accounts, news, and networking.

Build Chainlink

Install Go 1.23, and add your GOPATH's bin directory to your PATH
- Example Path for macOS export PATH=$GOPATH/bin:$PATH & export GOPATH=/Users/$USER/go
Install NodeJS v20 & pnpm v10 via npm.
- It might be easier long term to use nvm to switch between node versions for different projects. For example, assuming $NODE_VERSION was set to a valid version of NodeJS, you could run: nvm install $NODE_VERSION && nvm use $NODE_VERSION
Install Postgres (>= 12.x). It is recommended to run the latest major version of postgres.
- Note if you are running the official Chainlink docker image, the highest supported Postgres version is 16.x due to the bundled client.
- You should configure Postgres to use SSL connection (or for testing you can set ?sslmode=disable in your Postgres query string).
Download Chainlink: git clone https://github.com/smartcontractkit/chainlink && cd chainlink
Build and install Chainlink: make install
Run the node: chainlink help

For the latest information on setting up a development environment, see the Development Setup Guide.

Build from PR

To build an unofficial testing-only image from a feature branch or PR. You can do one of the following:

Send a workflow dispatch event from our docker-build workflow.
Add the build-publish label to your PR and then either retry the docker-build workflow, or push a new commit.

Build Plugins

Plugins are defined in yaml files within the plugins/ directory. Each plugin file is a yaml file and has a plugins. prefix name. Plugins are installed with loopinstall.

To install the plugins, run:

make install-plugins

Some plugins (such as those in plugins/plugins.private.yaml) reference private GitHub repositories. To build these plugins, you must have a GITHUB_TOKEN environment variable set, or preferably use the gh GitHub CLI tool to use the GitHub CLI credential helper like:

# Sets up a credential helper.
gh auth setup-git

Then you can build the plugins with:

make install-plugins-private

Docker Builds

To build the experimental "plugins" Chainlink docker image, you can run this from the root of the repository:

# The GITHUB_TOKEN is required to access private repos which are used by some plugins.
export GITHUB_TOKEN=$(gh auth token) # requires the `gh` cli tool.
make docker-plugins

Ethereum Execution Client Requirements

In order to run the Chainlink node you must have access to a running Ethereum node with an open websocket connection. Any Ethereum based network will work once you've configured the chain ID. Ethereum node versions currently tested and supported:

[Officially supported]

Parity/Openethereum (NOTE: Parity is deprecated and support for this client may be removed in future)
Geth
Besu

[Supported but broken] These clients are supported by Chainlink, but have bugs that prevent Chainlink from working reliably on these execution clients.

Nethermind Blocking issues:
- ~https://github.com/NethermindEth/nethermind/issues/4384~
Erigon Blocking issues:
- https://github.com/ledgerwatch/erigon/discussions/4946
- https://github.com/ledgerwatch/erigon/issues/4030#issuecomment-1113964017

We cannot recommend specific version numbers for ethereum nodes since the software is being continually updated, but you should usually try to run the latest version available.

Running a local Chainlink node

NOTE: By default, chainlink will run in TLS mode. For local development you can disable this by using a dev build using make chainlink-dev and setting the TOML fields:

[WebServer]
SecureCookies = false
TLS.HTTPSPort = 0

[Insecure]
DevWebServer = true

Alternatively, you can generate self signed certificates using tools/bin/self-signed-certs or manually.

To start your Chainlink node, simply run:

chainlink node start

By default this will start on port 6688. You should be able to access the UI at http://localhost:6688/.

Chainlink provides a remote CLI client as well as a UI. Once your node has started, you can open a new terminal window to use the CLI. You will need to log in to authorize the client first:

chainlink admin login

(You can also set ADMIN_CREDENTIALS_FILE=/path/to/credentials/file in future if you like, to avoid having to login again).

Now you can view your current jobs with:

chainlink jobs list

To find out more about the Chainlink CLI, you can always run chainlink help.

Check out the doc pages on Jobs to learn more about how to create Jobs.

Configuration

Node configuration is managed by a combination of environment variables and direct setting via API/UI/CLI.

Check the official documentation for more information on how to configure your node.

External Adapters

External adapters are what make Chainlink easily extensible, providing simple integration of custom computations and specialized APIs. A Chainlink node communicates with external adapters via a simple REST API.

For more information on creating and using external adapters, please see our external adapters page.

Verify Official Chainlink Releases

We use cosign with OIDC keyless signing during the Build, Sign and Publish Chainlink workflow.

It is encourage for any node operator building from the official Chainlink docker image to verify the tagged release version was did indeed built from this workflow.

You will need cosign in order to do this verification. Follow the instruction here to install cosign.

# tag is the tagged release version - ie. 2.16.0
cosign verify index.docker.io/smartcontract/chainlink:${tag} \
      --certificate-oidc-issuer https://token.actions.githubusercontent.com \
      --certificate-identity "https://github.com/smartcontractkit/chainlink/.github/workflows/build-publish.yml@refs/ta

Chainlink

Install / Use

README