Horizon is the client facing API server for the Stellar ecosystem. It acts as the interface between stellar-core and applications that want to access the Stellar network. It allows you to submit transactions to the network, check the status of accounts, subscribe to event streams, etc. See an overview of the Stellar ecosystem for more details.
Horizon requires go 1.6 or higher to build. See (https://golang.org/doc/install) for installation instructions.
gb is used for building horizon.
Given you have a running golang installation, you can install this with:
go get -u github.com/constabulary/gb/...
Next, you must download the source for packages that horizon depends upon. From within the project directory, run:
gb vendor restore
Then, simply run
gb build. After successful
completion, you should find
bin/horizon is present in the project directory.
More detailed intructions and admin guide.