Postchain REST API
Postchain is the blockchain framework that Chromia is built on. In the Chromia ecosystem, Providers run Postchain nodes that form the infrastructure for the network. Sometimes it makes sense to run your own node or set of nodes, such as for testing, development, or even for setting up your own consortium blockchain network.
Postchain nodes expose a REST API that allows for submitting transactions, posting queries, fetching block info, reading node status, etc. You can read the full API documentation here.