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

1. 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.)
2. 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.