Which layer does OCAP unify?

OCAP means Open Chain Access Protocol. It abstracts access to chain data; ArcBlock’s 2019 introduction describes GraphQL-based access across chains.

An application showing records from multiple chains can reuse a query approach while still accounting for different data meanings, confirmation rules and available fields.

This is different from an asset bridge and does not create shared consensus. The historical article explains the design; current networks, fields and endpoints require service-specific checks.

Preparing a transaction does not authorize it

The access-layer patent describes a service preparing unsigned transactions and returning them to the client for signing. The client must still check the network, recipient, asset, amount, and applicable costs. Keeping the private key on the client does not make incorrect signing content safe.

A common response format also leaves the application responsible for data freshness and confirmation meaning. A service may return a processed view that lags behind the chain. GraphQL describes how to ask for fields; it is not a proof that those fields are correct.

One interface, multiple chains: which differences must remain visible? follows the request, adapter, signing, and broadcast flow, with an acceptance exercise.

Sources and further reading

Related patent

Blockchain adapter, protocol, and access layer connects this concept to a disclosed technical design and its original patent record.

OCAP’s Three Generations: From Chain Access to AFS connects the original ODBC inspiration with Playground, Blocklet, and ARC’s resource-access model.