Each example is a runnable stdio language server. The parsers are deliberately small, so the protocol interaction stays visible.

Run an example

cargo run -p lspf --example hover

The process waits for an LSP client on stdin. In this repository, run Run LSP example client (select example) from VS Code to open an Extension Development Host connected to the selected server.

Every example logs to stderr because stdout carries the LSP wire protocol. RUST_LOG selects the events—use RUST_LOG=lspf=trace for the full framework trace—and LSPF_LOG_FORMAT=json writes one machine-readable event per line. Any other format value produces plain text.

Language features

Example	What it demonstrates
code_actions	Code actions
code_lens	Code lens, resolve, commands, and workspace edits
colors	Document colors and color presentations
formatting	Document, range, and on-type formatting
goto	Declaration, definition, implementation, type definition, and references
hover	Hover results built from synchronized document text
inlay_hints	Inlay hints and resolve
links	Document links and resolve
publish_diagnostics	Push diagnostics from document hooks
pull_diagnostics	Document and workspace diagnostic requests
rename	Prepare rename and rename
semantic_tokens	Full, delta, and range semantic tokens
symbols	Document and workspace symbols

Framework behavior

Example	What it demonstrates
server_features	Commands, progress, configuration, async work, and dynamic registration
blocking_work	Keeping blocking work off async executor threads

Transport examples

The transport examples reuse the same handlers so application logic does not change with the host:

cargo check -p lspf --example native_tcp --no-default-features --features tcp
cargo check -p lspf --example native_websocket --no-default-features --features websocket

Run Run LSP example client over a socket (select transport) in VS Code and choose tcp or websocket to start an example and connect the editor's own language client to it. Zed launches language servers over stdio and cannot connect to these socket examples.

For an unattended check of both adapters, run:

node tools/lsp-transport-probe/main.mjs both

The transport guide covers native sockets and browser or Node workers, including build and host commands.