Welcome to the ArcBlock OCAP (
Open Chain Access Protocol) documentation!
OCAP is an open-source protocol that provides an abstract layer for accessing underlying blockchains and enables your application to work across different blockchains in a unified way.
OCAP uses GraphQL as the unified language to provide the capability to read/write data on the blockchains:
queryis used to read blockchain data, such as blocks, transactions and accounts;
mutationis used to write data to blockchain, such as sending signed transaction and call contract;
subscriptionis used to listen blockchain data updates, such as new block/transaction stream;
Ethereum are supported by OCAP currently, and we are working hard to support more public blockchains.
If you have no idea about what GraphQL is, but want to quickly try various APIs provided by OCAP service, query data with playground is a very good starting point.
If you know the basis about GraphQL, and want to start building something on top of OCAP immediately, checkout the OCAP DApp bootstrapping instructions below:
- Bootstrap an Web Application, get an OCAP powered webapp up and running within 5 minutes
- Bootstrap an Android Application
- Bootstrap an iOS Application
To learn the supported SDK we built, checkout the OCAP SDK.
Want to see something built on top of OCAP by arcblockers? checkout tools for OCAP.
For a list of applications built on top of OCAP service by developers during our hackathon, checkout the ArcBlock Hackathon Github Organization.
To contribute to the documentation, see this file for details of the build process and considerations when making changes.