Status and roadmap

JsonRpcRemote is in pre-alpha and under active development. Its interfaces can still change from one release to the next, and more features are coming. This page lists what works today and what is planned. Ideas and problems are welcome as issues.

Available today

Client library JsonRpcRemote

• Connects to a server over TCP, or starts the server itself and talks to it over its stdin and stdout; see TCP and stdio.
• Imports a remote library with positional and named arguments from the suite, and offers its keywords with their arguments, types, defaults, documentation, tags and sources; see the arguments of JsonRpcRemote.
• Writes the log messages of a remote keyword to the Robot Framework log while the keyword runs.
• Starts a session per test, per suite or for the whole run; see Sessions and rpc_scope.
• Detects lost connections, waits for a server that is not reachable yet, and reconnects with a check of the library definition; see Lost connections and connect retry.

Server robot-jsonrpcremote-server

• Makes almost any Robot Framework library remote without code: Robot Framework itself imports and runs it, including its argument conversion.
• Serves several libraries, to several clients at the same time; see Several libraries on one server.
• Takes Robot Framework’s --pythonpath, --variable, --variablefile and --outputdir; see the server options.
• Stops in an orderly way on SIGTERM and SIGINT, also in a container.

Protocol

• JSON-RPC 2.0 with the framing of the Language Server Protocol, defined in the package robotframework-jsonrpcremote-protocol, with a hand-written example server; see the protocol.
• Between Python peers, keyword arguments and return values that JSON cannot carry travel as pickles, so they keep their type.

Planned

• More transports: named pipes, Unix domain sockets, WebSockets and Streamable HTTP, and encryption with TLS.
• Servers in other languages: example servers in other languages, such as Rust, Java and .NET, and values that every language can read. The Python implementation sends lists and dicts of JSON values as plain JSON, and other values by these conventions:
  • date and time as ISO 8601 strings, such as "2025-12-18T14:30:00+00:00";
  • binary data as Base64 strings;
  • decimal numbers as strings, to keep their precision, such as "123.45";
  • UUIDs as strings, such as "123e4567-e89b-12d3-a456-426614174000";
  • paths as strings, preferably with / as the separator;
  • other objects as JSON objects with a field such as __type__ that names the type, such as {"__type__": "MyCustomObject", "id": 1, "name": "foo"}.
• A Robot Framework process per session on the server, so that sessions run apart from each other.
• Keyword timeouts and cancellation, including the test and keyword timeouts of Robot Framework.
• Failure modes: continuable, fatal and skipped failures of remote keywords, with the type and the traceback of the error.
• Access control for the server and protection of the values that travel as pickles.
• Several libraries over one connection, and progress messages while a keyword runs.