Capsula Active

A terminal UI for safely managing SSH configuration — browse, edit, connect, and check reachability without rewriting the parts you did not touch.

Year: 2026
Built with: Go 1.26, Bubble Tea, OpenSSH
Source: github.com/adriandeleon/Capsula

Capsula's keyboard-driven new-host form showing fields for an SSH alias, hostname, user, port, identity file, and proxy jump.

Capsula is a terminal interface for ~/.ssh/config, built around one rule: it is your file. Untouched blocks are returned byte for byte, preserving comments, indentation, Key=Value forms, line endings, and directives the UI does not understand.

Editing without data loss

The form manages the common connection fields, but an SSH block can contain well over a hundred different keywords. Capsula changes only the values you actually edited and splices those changes back into the original bytes. An unedited round trip is exact by construction.

Edits stay in memory until you explicitly save. Writes are atomic, the previous contents are backed up, unsafe newlines are rejected, and a structural mismatch makes the file read-only rather than risking a bad rewrite.

OpenSSH remains the authority

SSH configuration precedence involves wildcards, includes, Match blocks, tokens, and first-value-wins rules. Instead of reimplementing that behavior, Capsula asks ssh -G for the effective connection and shows where it differs from the block on screen.

From the keyboard you can add, edit, delete, filter, save, connect, check host reachability, and repair unsafe permissions. Hosts behind a proxy are reported as unknown rather than incorrectly marked down.