Adamantine

A keyboard-first terminal editor built alongside the Adamas compiler.

Adamantine is written in Crystal and built on crystal_tui. It is intentionally small and hackable. Adamas is its home toolchain, while language intelligence comes through LSP, so the editor can also work with Crystal and other languages.

[!NOTE] Adamantine is an early preview. It is useful today, but configuration and key bindings may still evolve before the first stable release.

Highlights

• Multiple files in tabs, a project tree, mouse support, and configurable keys
• Find in file, bounded project search, replace, marks, and jump history
• Undo and redo across normal editor input
• Built-in dark, light, and high-contrast themes, plus JSON theme files
• LSP diagnostics, hover, signatures, definitions, references, semantic tokens, and code folding, plus completion and code-action previews
• PATH-based Adamas language-server discovery, with explicit CLI and environment overrides
• Written and tested entirely in Crystal

Quick start

You need Crystal and Shards. The current development baseline is Crystal 1.21.0.

git clone https://github.com/skuznetsov/adamantine.git
cd adamantine
shards install
make build
./bin/adamantine .

Run directly from source while developing:

make run ARGS="--theme vscode-dark /path/to/project"

See all CLI options with ./bin/adamantine --help.

Everyday controls

Action	Default binding
Command palette	Esc Esc or Ctrl+Shift+P
Quick actions	Shift+Enter
Save	Ctrl+S
Close tab	Ctrl+W
Undo / redo	Ctrl+Z / Ctrl+Shift+Z
Find in file	Ctrl+F
Find in project	Alt+F
File tree / editor	F2 / F3
Go to definition	F12
Hover / references / signature	F6 / F7 / F8
LSP actions	F9
Help	F5

Some terminals reserve particular key combinations. Every application action can be remapped in a JSON keymap; keymap.example.json is a complete starting point.

Command palette

Open the palette and enter commands without the leading colon shown below:

:w                         save
:q                         close the active tab
:quit                      quit if every buffer is clean
:q!                        force quit and discard unsaved changes
:wq                        save and quit
:open path/to/file.cr       open a file inside the project
:cd path/to/project         change the project root
:find pattern               find in the active file
:grep [-i] pattern          search the project
:s/old/new/gic              replace; g=all, i=ignore case, c=preview
:buf [number]               list or select open buffers
:mark name                  create a mark
:jump name                  jump to a mark
:theme vscode-light         switch theme

/pattern opens forward search directly. After closing the search panel, n and N repeat the search forward and backward.

LSP support

Without an explicit command, Adamantine detects the project language and looks for compatible server executables on PATH, preferring adamas_lsp. It never executes a server discovered inside the project tree; select one explicitly only when you trust it:

./bin/adamantine . --lsp crystalline
./bin/adamantine . --lsp crystal-tool-lsp --lsp-arg --stdio
EDITOR_LSP=/path/to/language-server ./bin/adamantine .
./bin/adamantine . --no-lsp

ADAMANTINE_LSP is the application-specific environment override; EDITOR_LSP is accepted as a generic alternative.

LSP capabilities depend on the selected server. The editor remains usable without one. Completion and code-action results are currently previews; Adamantine does not yet apply server-provided completion edits, code actions, renames, or workspace edits.

Configuration and themes

Pass a keymap or theme explicitly:

./bin/adamantine . --config ~/.config/adamantine/config.json
./bin/adamantine . --theme ~/.config/adamantine/theme.json

Built-in theme names include vscode-dark, vscode-light, and vscode-high-contrast. The editor also checks ~/.config/adamantine/config.json for its default keymap.

Existing preview installations remain compatible with CRYSTAL_EDITOR_CONFIG, CRYSTAL_EDITOR_THEME, CRYSTAL_EDITOR_LSP, and the old ~/.config/crystal_editor and ~/.crystal_editor directories. New installations should use the Adamantine names.

Development

shards install
make check

make check verifies formatting, builds the binary, and runs the full spec suite. The LSP handshake is deliberately separate because it requires a local server executable and Ruby:

ADAMANTINE_LSP=/path/to/server make check-lsp

Run make help for the complete target list. Contributions and focused bug reports are welcome; please include your Crystal version, terminal, operating system, and the smallest reproduction you can provide.

See ARCHITECTURE.md for the component boundaries and event flow.

Project status

The editor is optimized for source-sized projects and interactive terminal use. Project search intentionally caps traversal, file size, and result count to keep the UI responsive. Large-file performance, cross-platform terminal quirks, packaged binaries, and compatibility across language servers are still active areas of work.

License

MIT