Chain Core Developer Edition

Chain Core is enterprise software that enables institutions to issue and transfer financial assets on permissioned blockchain networks. Using Chain Core, institutions can launch and operate a blockchain network, or connect to a growing list of other networks that are transforming how assets move around the world.

Chain Core Developer Edition is a free, downloadable version of Chain Core that is open source and licensed under the AGPL. Individuals and organizations use Chain Core Developer Edition to learn, experiment, and build prototypes.

Chain Core Developer Edition can be run locally on Mac, Windows, or Linux to create a new blockchain network, connect to an existing blockchain network, or connect to the public Chain testnet, operated by Chain, Microsoft, and Cornell University’s IC3.

For more information about how to use Chain Core Developer Edition, see the docs: https://chain.com/docs

Download

To install Chain Core Developer Edition on Mac, Windows, or Linux, please visit our downloads page.

Contributing

Chain has adopted the code of conduct defined by the Contributor Covenant. It can be read in full here. This repository is the canonical source for Chain Core Developer Edition. Consequently, Chain engineers actively maintain this repository. If you are interested in contributing to this code base, please read our issue and pull request templates first.

Building from source

• Go version 1.7, with $GOPATH set to your preferred directory
• Postgres (we suggest Postgres.app), along with the command line tools
• protoc, if you need to compile protos

Environment

Set the CHAIN environment variable, in .profile in your home directory, to point to the root of the Chain source code repo:

export CHAIN=$GOPATH/src/chain

You should also add $CHAIN/bin to your path (as well as $GOPATH/bin, if it isn't already):

PATH=$GOPATH/bin:$CHAIN/bin:$PATH

You might want to open a new terminal window to pick up the change.

Installation

Build and install from source:

$ git clone https://github.com/chain/chain $CHAIN
$ cd $CHAIN
$ go install ./cmd/...

Set up the database:

$ createdb core

Start Chain Core:

$ cored

Access the dashboard:

$ open http://localhost:1999/

Run tests:

$ go test $(go list ./... | grep -v vendor)

Developing Chain Core

Updating the schema with migrations

$ dumpschema

Dependencies

To add or update a Go dependency, do the following:

Copy the code from $GOPATH/src/x to $CHAIN/vendor/x. For example, to vendor the package github.com/kr/pretty, run

$ mkdir -p $CHAIN/vendor/github.com/kr
$ rm -r $CHAIN/vendor/github.com/kr/pretty
$ cp -r $GOPATH/src/github.com/kr/pretty $CHAIN/vendor/github.com/kr/pretty
$ rm -rf $CHAIN/vendor/github.com/kr/pretty/.git

(Note: don't put a trailing slash (/) on these paths. It can change the behavior of cp and put the files in the wrong place.)

In your commit message, include the commit hash of the upstream repo for the dependency. (You can find this with git rev-parse HEAD in the upstream repo.) Also, make sure the upstream working tree is clean. (Check with git status.)

Deploy Options

When Chain Core is deployed to a non-local host, all requests require authentication. To generate a client access token on Heroku, run the following command:

$ heroku run -a <your-heroku-app> corectl create-token <token-name>
<token-name>:<your-token>

License

Chain Core Developer Edition is licensed under the terms of the GNU Affero General Public License Version 3 (AGPL).

The Chain Java SDK (/sdk/java) is licensed under the terms of the Apache License Version 2.0.