Use a language server

For managed Rust on GNU/Linux x86-64, run M-x lsp-install-server (or :lsp-install-server in modal Normal), then choose rust-analyzer. Install curl, gzip and sha256sum separately if they are missing. The operation runs while editing remains available, verifies an exact release and saves the server choice. It preserves the current LSP mode: use lsp-mode separately to enable continuous analysis. Missing Rust toolchain or sources require a separate toolchain installation.

The equivalent lsp-setup path is rust, then install:rust-analyzer. lsp-servers shows progress and ready/incomplete installations. If settings changed during the operation, the verified payload stays ready and unselected. Choose its ready:<id> entry to reuse it after resolving the configuration conflict; no second download is needed.

For managed Go, choose gopls in lsp-install-server, or go then install:gopls in lsp-setup. Install Go separately first. Acquisition uses the local compiler and reports an insufficient version without downloading a replacement toolchain.

For TypeScript/JavaScript/TSX, choose typescript-language-server, then the language to select. For HTML/CSS/JSON, choose vscode-langservers-extracted, then the language. These recipes require installed Node/npm, retain exact package versions and a lockfile, and disable package scripts. TypeScript remains on major

1. The web package supplies three independently verified profiles; select another

language later through its same ready:<id> entry without another installation. Each choice inherits known associations and current settings. Use lsp-mode separately to enable analysis.

For Markdown, Ruby, Python or Odin, choose the corresponding recipe in lsp-install-server, or use its language ID then install:<recipe> in lsp-setup:

These recipes run on Linux x86-64. Marksman verifies its official release SHA-256. Ruby keeps the server and a concrete Bundler version in an owned gem home with a frozen lock. Python installs only the base server into an owned virtual environment; its final path is retained for entrypoint shebangs. OLS builds one immutable upstream revision with your installed compiler and retains its builtin collection. It disables snippet-only options. A compiler mismatch reports a failed/incomplete candidate; rev does not upgrade Odin. If Odin has no known association, answer the patterns prompt with ["*.odin"]. All choices preserve the current analysis mode and remain optional. Org and languages outside this catalog use the same installed/custom registration flow.

Use an installed language server to complete names from unsaved text in the same popup as native completion. Rust uses rust-analyzer by default. Keep the server executable on PATH, or configure its absolute path. Existing/custom registration reuses that executable without downloading another one.

Register or select an installed server

Run M-x lsp-setup (or :lsp-setup in modal Normal). Enter the language ID, then an existing compatible server name, an installed recipe preset, a new profile name, or native-only. Language suggestions include known associations, configured identities and recipe languages; another valid identity can still be typed. For a new profile, enter the executable separately from its JSON argument array, then its JSON root-marker array. Empty answers keep the inherited selected profile's arguments and markers; enter [] to clear them. Settings and literal environment overrides also inherit from that profile.

Known language associations are reused. For a new identity such as elixir, enter a JSON pattern array such as ["*.ex", "*.exs"] when asked. No grammar or recipe is required. C-g cancels; modal Escape also cancels. Nothing is saved until all answers form an admitted complete configuration.

Setup saves and applies the choice without enabling LSP. Use lsp-mode to activate it and lsp-status to check its actual transport readiness. A missing executable remains a recoverable prerequisite failure.

Inspect recipes and change sources

Run lsp-servers to open a read-only snapshot. It shows each language's selected source, all configured profiles, local executable availability, and the managed recipe catalog with its optional acquisition prerequisites. It also reads bounded managed facts to show versions, readiness, current job phase and selected profiles. It runs no helper and looks up no remote versions. Available external executables have not necessarily completed LSP initialization; use lsp-status for the current file. Use ordinary buffer switching to return to your source.

For an already installed Go server, choose go, then recipe:gopls in lsp-setup. The preset observes the executable on the inherited PATH and suggests its structured launch arguments. Existing root markers, initialization options, settings and literal environment values inherit from the selected profile. Empty answers keep those values; [] clears arguments or markers. Known *.go and user associations are reused without another patterns prompt. A preset never overwrites a configured profile with the same name. If the executable is missing, choose an installed absolute path or inspect the catalog prerequisites.

Use lsp-select-server to change an existing language's source without registering a new executable. Enter its language ID, then a compatible configured profile, ready:<id> installation or native-only. It saves and applies the choice without changing global LSP mode. A language without known associations asks for patterns; a catalog entry or grammar is not required. C-g or modal Escape cancels without writing settings.

Update, cancel or remove a managed server

Open lsp-servers and note the managed installation ID. Run lsp-update-server through M-x or modal colon, choose that ID, and check the selected profile names shown before answering yes. One verified replacement updates those profiles in one settings publication. A shared web package updates all selected profiles that still use its original command and arguments. Current options and known associations stay intact; custom commands and arguments are preserved.

The old payload stays installed. A failed acquisition leaves its selected profiles unchanged. A configuration conflict keeps the replacement ready and unselected; inspect the changed configuration before choosing its ready:<id> entry. Updating an unselected installation creates a ready replacement without selecting it implicitly. Analysis remains in its current mode.

Run lsp-cancel-installation while editing to cancel an active management job. Its worker slot stays occupied until owned helpers stop and are reaped. C-g, or modal Escape, cancels an unanswered management prompt. Confirmed editor exit also cancels active work; cancelling an exit prompt keeps the session running. A candidate interrupted after allocation stays incomplete and is never resumed or selected automatically.

To remove a managed payload, run lsp-remove-server, choose its ID and confirm yes. Every profile in the selected configuration graph must stop referencing it, including unselected profiles. Selecting native-only leaves a profile table in place, so change or remove that old table and adjust any preferences before reloading settings. Stop connections that still use the payload in every owning rev session; disabling that session's LSP mode requests their shutdown. Retry removal after those servers finish stopping.

Removal leaves settings and external executables unchanged. It can also remove an incomplete record whose payload is already absent. Cleanup failures retain truthful incomplete records for inspection. Only marked idle acquisition caches are cleaned; active, unmarked and legacy entries remain untouched.

Enable Rust completion

Open a Rust project containing Cargo.toml, then run M-x lsp-mode. This enables LSP for this session and automatically attaches eligible files as you visit them. Run M-x lsp-status to inspect the current connection. A ready connection can still return no suggestions while the server loads its workspace.

For a persistent choice, change the existing table in ~/.config/rev/config.toml and restart rev:

[lsp]
enabled = true

Use rev/config.toml beneath XDG_CONFIG_HOME when that variable is set. This excerpt replaces the existing value; do not append a duplicate table. The complete sample includes the default Rust server.

In a Rust file, try a local field:

struct Widget { unsaved_field: u32 }
fn main() {
    let item = Widget { unsaved_field: 7 };
    item.uns
}

Leave the cursor after uns and request M-x completion-at-point. You can also wait for the normal typing delay. The popup includes the field:

item.uns
┌──────────────────────┐
│◆ unsaved_field  field│
└──────────────────────┘

The indicator and type label use syntax colors. The list can contain other server candidates, and its width follows the pane. Edit the field name without saving and request again: suggestions follow the current buffer. Use arrows or C-p/C-n, accept with Tab/Return, and undo with C-/.

If a server supplies an import with the selected completion, its checked same-document edits and the name apply together in one undo operation. Acceptance can wait briefly for item resolution. Keep editing or press C-g to cancel; a partial import or primary-only fragment is not applied after resolution fails. Completion never saves the file.

Exclude or restore a buffer

Run M-x lsp-disconnect to use native completion for the current buffer. The exception covers all views of that buffer and survives visits to other files. Run M-x lsp-connect to restore its eligibility. Restoring does not enable LSP when the global session mode is disabled. Closing the buffer clears its exception. Other buffers sharing the same root keep their server.

Run M-x lsp-mode again to disable LSP for the session and stop its owned servers. Native completion remains available within its supported language contexts.

Recover a failed server

Inspect M-x lsp-status. For a missing executable, restore the binary at its configured path. A failed connection remains unavailable across repeated requests and buffer visits. After restoring the prerequisite, run M-x lsp-restart from an eligible file. It replaces that root's connection and reopens its documents with current unsaved text. Other roots and buffer exclusions stay unchanged.

Run lsp-reload-settings after editing server entries, preferences or file associations in the selected user root or its includes. It preserves the running LSP mode, buffer exclusions and startup editing profile. Restart rev after changing its inherited process environment, such as PATH. Disabling and re-enabling lsp-mode also permits a new launch attempt with the existing settings. Empty results, timeouts and unavailable servers use native fallback; ordinary editing continues.

Connect another installed server

Add an entry for its executable, language ID and project markers. For example, replace these invented names with those of your installed server:

[files.associations]
"*.demo" = "demo"

[lsp.servers.demo]
languages = ["demo"]
command = "demo-language-server"
args = ["--stdio"]
root_markers = ["project.demo"]
initialization_options = {}
settings = {}

Merge these leaves into existing tables. Arguments are literal strings, without shell or environment expansion. The server must support the admitted protocol profile. A bundled grammar is not required for semantic completion. Syntax coloring and native fallback still depend on their own language support.