Clio is an XRP Ledger API server optimized for RPC calls over WebSocket or JSON-RPC. It stores validated historical ledger and transaction data in a more space efficient format, and uses up to 4 times less space than rippled.

Clio can be configured to store data in Apache Cassandra or ScyllaDB, enabling scalable read throughput. Multiple Clio nodes can share access to the same dataset, which allows for a highly available cluster of Clio nodes without the need for redundant data storage or computation.

Clio offers the full rippled API, with the caveat that Clio by default only returns validated data. This means that ledger_index defaults to validated instead of current for all requests. Other non-validated data, such as information about queued transactions, is also not returned.

Clio retrieves data from a designated group of rippled nodes instead of connecting to the peer-to-peer network. For requests that require access to the peer-to-peer network, such as fee or submit, Clio automatically forwards the request to a rippled node and propagates the response back to the client. To access non-validated data for any request, simply add ledger_index: "current" to the request, and Clio will forward the request to rippled.

Below are some useful docs to learn more about Clio.

For Developers:

• How to build Clio
• Coverage report

For Operators:

• How to configure Clio and rippled
• How to run Clio
• Logging
• Troubleshooting guide

General reference material:

• API reference
• Developer docs
• Clio documentation

Feel free to open an issue if you have a feature request or something doesn't work as expected. If you have any questions about building, running, contributing, using Clio or any other, you could always start a new discussion.