$ layout

# Names: a regex or a cap, used below as $name
$component: [A-Z][a-zA-Z0-9]*          # e.g. Button, UserCard
$hook:      use[A-Z][a-zA-Z0-9]*       # e.g. useAuth, useTheme
$code:      <=400                      # At most 400 lines

# The tree: every entry this repo may hold
README.md                              # One: a plain name is exactly one file
package.json
?CHANGELOG.md                          # ? marks an entry optional
src/                                   # The app
  main.tsx
  components/                          # One component per file
    $component.tsx $code               # Many: a pattern matches any number
    ?$component.test.tsx               # An optional test beside it
  hooks/                               # One hook per file
    $hook.ts $code                     # A hoisted cap
public/                                # Static files, served as is
  {}                                   # Anything goes here
docs -> ../docs                        # A symlink

# Names: a regex or a cap, used below as $name
$mod:  [a-z][a-z0-9_]*                 # e.g. parser, http_client
$code: <=800                           # At most 800 lines

# The tree: every entry this repo may hold
README.md                              # One: a plain name is exactly one file
pyproject.toml
repo.layout                            # This contract
?uv.lock                               # ? marks an entry optional
src/                                   # The package, under src/
  app/                                 # The import name
    __init__.py
    $mod.py $code                      # Many: one module per concern
    ?{$mod}_test.py                    # An optional test beside it

# Names: a regex or a cap, used below as $name
$cmd:  [a-z][a-z0-9-]*                 # e.g. api, migrate-db
$pkg:  [a-z][a-z0-9]*                  # e.g. auth, billing
$file: [a-z][a-z0-9_]*                 # e.g. handler, user_store
$code: <=1,000                         # At most 1,000 lines

# The tree: every entry this repo may hold
README.md
go.mod
?go.sum
repo.layout                            # This contract
cmd/                                   # One folder per binary
  $cmd/                                # One binary, named by its folder
    main.go
internal/                              # Private to this module
  $pkg/                                # One package per folder
    $file.go $code
    ?{$file}_test.go                   # An optional test beside it
pkg/                                   # Importable by other modules
  $pkg/                                # A public package
    {}                                 # Anything goes here