Formatters

altimate auto-formats files after editing using language-specific formatters.

How It Works

When a file is modified by an agent, altimate:

1. Detects the file extension
2. Finds a matching formatter
3. Checks if the formatter is available (binary in PATH or project dependency)
4. Runs the formatter on the modified file

Supported Formatters

Formatter	Extensions	Detection	Command
prettier	.js, .jsx, .ts, .tsx, .json, .yaml, .md	package.json deps	bun x prettier --write $FILE
biome	.ts, .js, .json, .css, .html	biome.json	bun x @biomejs/biome check --write $FILE
gofmt	.go	gofmt in PATH	gofmt -w $FILE
rustfmt	.rs	rustfmt in PATH	rustfmt $FILE
ruff	.py, .pyi	ruff binary + config	ruff format $FILE
clang-format	.c, .cpp, .h	.clang-format file	clang-format -i $FILE
ktlint	.kt, .kts	ktlint in PATH	ktlint -F $FILE
mix	.ex, .exs, .eex, .heex	mix in PATH	mix format $FILE
dart	.dart	dart in PATH	dart format $FILE
shfmt	.sh, .bash	shfmt in PATH	shfmt -w $FILE
terraform	.tf, .tfvars	terraform in PATH	terraform fmt $FILE
gleam	.gleam	gleam in PATH	gleam format $FILE
nixfmt	.nix	nixfmt in PATH	nixfmt $FILE
rubocop	.rb, .rake, .gemspec	rubocop in PATH	rubocop --autocorrect $FILE
standardrb	.rb, .rake, .gemspec	standardrb in PATH	standardrb --fix $FILE
pint	.php	composer.json has laravel/pint	./vendor/bin/pint $FILE
ormolu	.hs	ormolu in PATH	ormolu -i $FILE
cljfmt	.clj, .cljs, .cljc, .edn	cljfmt in PATH	cljfmt fix --quiet $FILE
ocamlformat	.ml, .mli	.ocamlformat file	ocamlformat -i $FILE
zig	.zig, .zon	zig in PATH	zig fmt $FILE
air	.R	air --help output	air format $FILE
latexindent	.tex	latexindent in PATH	latexindent -w -s $FILE
htmlbeautifier	.erb	htmlbeautifier in PATH	htmlbeautifier $FILE
dfmt	.d	dfmt in PATH	dfmt -i $FILE
uv	.py, .pyi	uv binary (fallback)	uv format -- $FILE

Configuration

Disable All Formatting

{
  "formatter": false
}

Disable a Specific Formatter

{
  "formatter": {
    "prettier": {
      "disabled": true
    }
  }
}

Custom Formatter Configuration

{
  "formatter": {
    "prettier": {
      "command": ["npx", "prettier", "--write", "$FILE"],
      "extensions": [".ts", ".tsx", ".js"],
      "environment": {
        "NODE_ENV": "production"
      }
    }
  }
}

Field	Type	Description
command	string[]	Override the formatter command ($FILE is replaced)
extensions	string[]	Override file extensions
environment	object	Extra environment variables
disabled	boolean	Disable this formatter