RPC¶

fxv rpc runs a JSON-RPC 2.0 server that operates on a FlexVault workspace over stdin/stdout. A program starts the server once and makes as many calls as it needs, instead of running a separate fxv process per command.

This section is the protocol specification. This should outline the protocol in enough detail to allow implementors to create integrations in a straight forward manner.

It does not describe what the commands themselves do. The CLI Reference is canonical for that, and this section covers only what the RPC transport changes.

• Example Usage starts a server, makes a first call, and provides a simple client implementation in python.
• Protocol specifies the framing, the request and response objects, and the connection lifecycle.
• Methods lists every method the server answers and how each differs from the command line.
• Errors documents the error codes and what they contain.

When to use the RPC server¶

Each fxv command run from a shell starts a process, loads the workspace, does its work, and exits. That is the right model for interactive use, for scripts, and for CI, where commands run occasionally and process startup costs nothing that matters. Use the CLI for those, and see Integrate with CI and Automation for build system integration.

The RPC server suits a long-running program that queries the same workspace repeatedly: an editor or engine integration, a desktop client, or a tool that watches for changes. One server process handles the whole session.

Security¶

The server reads requests from its own standard input and writes responses to its own standard output. It does not open a socket, bind a port, or listen on a network.