SSH Config Toolkit

All-in-one editing support for SSH configuration files, both client and server, in VS Code: standalone syntax highlighting (any path), hover docs, keyword autocompletion, a configurable keyword linter, formatting, and Include-file links. No other extension required.

The idea is inspired by two following projects, that merges and fixes two existing extensions.

ssh-config-syntax-highlighter by R. Mousavian — a solid, self-contained syntax highlighter.
vscode-ssh-config-enhanced by jamief — hover docs, completion, formatting, and Include links.

It keeps the reliable, standalone highlighting of the first and the language-intelligence features of the second, with the bugs fixed and several features added.

Installation

Install the SSH Config Toolkit extension from the VS Code Marketplace, or from the cli:

code --install-extension debman.ssh-config-toolkit

Features

Client and server configs — full support for both ssh_config (client) and sshd_config (the SSH server daemon), each with its own grammar and its own directive set, so client-only and server-only keywords are highlighted, completed, and linted correctly.
Standalone syntax highlighting — self-contained TextMate grammars. No dependency on Remote-SSH or any other extension.
Works on files in any path — detection by filename (config, ssh_config, sshd_config), by glob (**/.ssh/config, /etc/ssh/ssh_config, /etc/ssh/sshd_config, …), and by first-line content. For anything unusual, run “SSH Config: Treat Current File as SSH Config / SSHD Config.”
Hover descriptions — hover any directive to see what it does (95 keywords documented from the ssh_config(5) manual).
Autocompletion — real keyword completion for every directive, plus Configure Host and Configure Tunnel block snippets.
Keyword linter — flags unknown/misspelled directives with a “did you mean …?” suggestion. Severity is configurable.
Value validation — checks directive values against the official OpenSSH value sets, so PermitRootLogin maybe or Compression sometimes are flagged. Only directives with a fixed, documented set of accepted values (booleans, enumerations, and Port) are checked; free-form directives like IdentityFile or LogLevel-style options are left alone to avoid false positives.
Fix keyword casing on save — normalises directive keywords to their canonical casing (e.g. hOstNaME → HostName) using the official OpenSSH keyword list. On by default; also available as the command “SSH Config: Fix Directive Casing.” Only the leading directive on each line is changed — values are never touched.
Formatter — indents directives under each Host/Match block and normalises blank lines. Run Format Document.
Include / key-file links — Include, IdentityFile, CertificateFile, and UserKnownHostsFile paths become Ctrl/Cmd-clickable. Resolves ~, absolute, and relative paths.
Open user config — command “SSH Config: Open User Configuration (~/.ssh/config)”, working correctly on macOS, Linux, and Windows.

What was fixed from the originals

The “Open User Configuration” command used the Windows-only USERPROFILE variable, so it always failed on macOS/Linux. It now uses the OS home directory on every platform.
The enhanced extension declared a hard dependency on ms-vscode-remote.remote-ssh and never defined the ssh_config language itself (its grammar was injection-only). Without Remote-SSH installed nothing activated. This fork defines its own language and standalone grammar, so it works on its own.
“Completion” previously offered only two hardcoded snippets; it now completes all real SSH directives.

Settings

Setting	Default	Description
`sshConfigToolkit.format.indentSize`	`2`	Spaces used to indent directives when formatting.
`sshConfigToolkit.lint.enabled`	`true`	Turn the keyword linter on/off.
`sshConfigToolkit.lint.severity`	`warning`	`error`, `warning`, `information`, or `hint`.
`sshConfigToolkit.lint.allowedKeywords`	`[]`	Extra directive names to treat as valid (custom or newer keywords).
`sshConfigToolkit.lint.validateValues`	`true`	Validate directive values against the official OpenSSH value sets.
`sshConfigToolkit.fixCasing.onSave`	`true`	Normalise directive keyword casing on save.

Keyword source & updates

The authoritative directive lists are generated from the official OpenSSH man pages — the source of truth for directive names and their canonical casing:

data/ssh-keywords.json ← ssh_config(5) (client)
data/sshd-keywords.json + data/sshd-options.json ← sshd_config(5) (server)

A small curated set of deprecated/vendor keywords lives alongside each (data/ssh-keywords-extra.json, data/sshd-keywords-extra.json) so older configs are still recognised.

The value-validation sets (data/ssh-values.json, data/sshd-values.json) are generated from the multistate tables in OpenSSH's readconf.c / servconf.c / servconf.h — the authoritative source for which directives accept a fixed set of values, and what those values are.

To refresh against a newer OpenSSH release for a future build:

node scripts/update-keywords.mjs            # client keywords: fetch latest ssh_config.5
node scripts/update-sshd.mjs                # server keywords + descriptions: sshd_config.5
node scripts/update-values.mjs              # value sets: readconf.c + servconf.c/.h
# each accepts a local file path (or, for update-values, a checkout dir) instead of fetching

Install the packaged build

In VS Code open the Extensions view, click the … menu → Install from VSIX…, and choose ssh-config-toolkit-*.vsix. (Or from a terminal: code --install-extension ssh-config-toolkit-*.vsix.)
Open your ~/.ssh/config — highlighting, hover, completion, and linting activate automatically.

Build from source

npm install
npm run build      # compile TypeScript -> out/
node test/core.test.mjs   # run the unit tests
npm run package    # produce the .vsix (requires @vscode/vsce)

AI Work

All the project development process done using Claude AI.

License

MIT. Directive descriptions in data/ssh-options.json derive from OpenSSH documentation; see data/OPTIONS-LICENSE.