diff --git a/flit/__init__.py b/flit/__init__.py
index 64e63e3a..f5b6e023 100644
--- a/flit/__init__.py
+++ b/flit/__init__.py
@@ -5,23 +5,13 @@
 import sys
 
 from . import common
+from .subcommand import register
 from .log import enable_colourful_output
 
 __version__ = '1.3'
 
 log = logging.getLogger(__name__)
 
-def add_shared_install_options(parser):
-    parser.add_argument('--user', action='store_true', default=None,
-        help="Do a user-local install (default if site.ENABLE_USER_SITE is True)"
-    )
-    parser.add_argument('--env', action='store_false', dest='user',
-        help="Install into sys.prefix (default if site.ENABLE_USER_SITE is False, i.e. in virtualenvs)"
-    )
-    parser.add_argument('--python', default=sys.executable,
-        help="Target Python executable, if different from the one running flit"
-    )
-
 def main(argv=None):
     ap = argparse.ArgumentParser()
     ap.add_argument('-f', '--ini-file', type=pathlib.Path, default='pyproject.toml')
@@ -31,53 +21,13 @@ def main(argv=None):
     )
     ap.add_argument('--debug', action='store_true', help=argparse.SUPPRESS)
     ap.add_argument('--logo', action='store_true', help=argparse.SUPPRESS)
-    subparsers = ap.add_subparsers(title='subcommands', dest='subcmd')
-
-    parser_build = subparsers.add_parser('build',
-        help="Build wheel and sdist",
-    )
-
-    parser_build.add_argument('--format', action='append',
-        help="Select a format to build. Options: 'wheel', 'sdist'"
-    )
-
-    parser_publish = subparsers.add_parser('publish',
-        help="Upload wheel and sdist",
-    )
-
-    parser_publish.add_argument('--format', action='append',
-        help="Select a format to publish. Options: 'wheel', 'sdist'"
-    )
 
-    parser_install = subparsers.add_parser('install',
-        help="Install the package",
-    )
-    parser_install.add_argument('-s', '--symlink', action='store_true',
-        help="Symlink the module/package into site packages instead of copying it"
-    )
-    parser_install.add_argument('--pth-file', action='store_true',
-        help="Add .pth file for the module/package to site packages instead of copying it"
-    )
-    add_shared_install_options(parser_install)
-    parser_install.add_argument('--deps', choices=['all', 'production', 'develop', 'none'], default='all',
-        help="Which set of dependencies to install. If --deps=develop, the extras dev, doc, and test are installed"
-    )
-    parser_install.add_argument('--extras', default=(), type=lambda l: l.split(',') if l else (),
-        help="Install the dependencies of these (comma separated) extras additionally to the ones implied by --deps. "
-             "--extras=all can be useful in combination with --deps=production, --deps=none precludes using --extras"
-    )
-
-    parser_installfrom = subparsers.add_parser('installfrom',
-       help="Download and install a package using flit from source"
-    )
-    parser_installfrom.add_argument('location',
-        help="A URL to download, or a shorthand like github:takluyver/flit"
-    )
-    add_shared_install_options(parser_installfrom)
-
-    parser_init = subparsers.add_parser('init',
-        help="Prepare pyproject.toml for a new package"
-    )
+    subparsers = ap.add_subparsers(title='subcommands', dest='subcmd')
+    register(subparsers, 'build')
+    register(subparsers, 'publish')
+    register(subparsers, 'install')
+    register(subparsers, 'installfrom')
+    register(subparsers, 'info')
 
     args = ap.parse_args(argv)
 
@@ -104,30 +54,9 @@ def main(argv=None):
         print(clogo.format(version=__version__))
         sys.exit(0)
 
-    if args.subcmd == 'build':
-        from .build import main
-        try:
-            main(args.ini_file, formats=set(args.format or []))
-        except(common.NoDocstringError, common.VCSError, common.NoVersionError) as e:
-            sys.exit(e.args[0])
-    elif args.subcmd == 'publish':
-        from .upload import main
-        main(args.ini_file, args.repository, formats=set(args.format or []))
-
-    elif args.subcmd == 'install':
-        from .install import Installer
-        try:
-            Installer(args.ini_file, user=args.user, python=args.python,
-                      symlink=args.symlink, deps=args.deps, extras=args.extras,
-                      pth=args.pth_file).install()
-        except (common.NoDocstringError, common.NoVersionError) as e:
-            sys.exit(e.args[0])
-    elif args.subcmd == 'installfrom':
-        from .installfrom import installfrom
-        sys.exit(installfrom(args.location, user=args.user, python=args.python))
-    elif args.subcmd == 'init':
-        from .init import TerminalIniter
-        TerminalIniter().initialise()
+    if args.subcmd:
+        exitcode = args.subcmd_entrypoint(args)
+        sys.exit(exitcode)
     else:
         ap.print_help()
         sys.exit(1)
diff --git a/flit/subcommand/__init__.py b/flit/subcommand/__init__.py
new file mode 100644
index 00000000..9a638e83
--- /dev/null
+++ b/flit/subcommand/__init__.py
@@ -0,0 +1,38 @@
+"""
+The "subcommand" package contains implementations for CLI commands in flit.
+
+Subcommands must:
+
+* Contain an implementation in ``flit/subcommand/<name>.py``
+* Be registered using ``flit.subcommand.register`` before parsing the arguments
+
+Each subcommand module must contain the following names:
+
+* NAME: the name of the command which is exposed in the CLI args (this is what
+  the user types to trigger that subcommand).
+* HELP: A short 1-line help which is displayed when the user runs
+  ``flit --help``
+* setup: A callable which sets up the subparsers. As a single argument it gets
+  a reference to the sub-parser. No return required.
+* run: A callable which gets executed when the subcommand is selected by the
+  end-user. As a single argument it gets a reference to the root
+  argument-parser. It should return an integer representing the exit-code of
+  the application.
+"""
+from importlib import import_module
+
+
+def register(main_parser, module_name):
+    """
+    This registers a new subcommand with the main argument parser.
+
+    :param main_parser: A reference to the main argument parser instance.
+    :param module_name: The base-name of the subcommand module. If a module is
+        added as ``flit/subcommand/foo.py``, this should be ``foo``. This value
+        is used to dynamically import the subcommend so it must be a valid
+        module name.
+    """
+    subcmd = import_module('flit.subcommand.%s' % module_name)
+    parser = main_parser.add_parser(subcmd.NAME,help=subcmd.HELP)
+    parser.set_defaults(subcmd_entrypoint=subcmd.run)
+    subcmd.setup(parser)
diff --git a/flit/subcommand/build.py b/flit/subcommand/build.py
new file mode 100644
index 00000000..b063cbb3
--- /dev/null
+++ b/flit/subcommand/build.py
@@ -0,0 +1,25 @@
+"""
+This module contains the implementation for the "build" subcommand.
+"""
+import sys
+
+from .. import common
+from ..build import main
+
+NAME = 'build'
+HELP = "Build wheel and sdist"
+
+
+def setup(parser):
+    parser.add_argument(
+        '--format', action='append',
+        help="Select a format to build. Options: 'wheel', 'sdist'"
+    )
+
+
+def run(args):
+    try:
+        main(args.ini_file, formats=set(args.format or []))
+    except(common.NoDocstringError, common.VCSError, common.NoVersionError) as e:
+        return e.args[0]
+    return 0
diff --git a/flit/subcommand/info.py b/flit/subcommand/info.py
new file mode 100644
index 00000000..1b842992
--- /dev/null
+++ b/flit/subcommand/info.py
@@ -0,0 +1,27 @@
+"""
+This module contains the implementation for the "info" subcommand
+"""
+
+import sys
+
+from .. import inifile
+from ..common import Module, make_metadata
+
+NAME = 'info'
+HELP = "Retrieve metadata information from the project"
+
+
+def setup(parser):
+    parser.add_argument(
+        '--version', default=False, action='store_true', dest='show_version',
+        help="Print the version number of the project to stdout"
+    )
+
+
+def run(args):
+    ini_info = inifile.read_pkg_ini(args.ini_file)
+    module = Module(ini_info['module'], args.ini_file.parent)
+    metadata = make_metadata(module, ini_info)
+    output = metadata.version
+    print(output)
+    return 0
diff --git a/flit/subcommand/init.py b/flit/subcommand/init.py
new file mode 100644
index 00000000..42b7662c
--- /dev/null
+++ b/flit/subcommand/init.py
@@ -0,0 +1,17 @@
+"""
+This module contains the implementation for the "init" subcommand
+"""
+
+from ..init import TerminalIniter
+
+NAME = 'init'
+HELP = "Prepare pyproject.toml for a new package"
+
+
+def setup(parser):
+    pass
+
+
+def run(args):
+    TerminalIniter().initialise()
+    return 0
diff --git a/flit/subcommand/install.py b/flit/subcommand/install.py
new file mode 100644
index 00000000..7890b168
--- /dev/null
+++ b/flit/subcommand/install.py
@@ -0,0 +1,52 @@
+"""
+This module contains the implementation for the "install" subcommand
+
+This module also contains a definition of ``add_shared_install_options`` which
+can be used to set up additional arguments for an "install-type" subcommand.
+"""
+
+import sys
+from ..install import Installer
+from .. import common
+
+NAME = 'install'
+HELP = "Install the package"
+
+
+def add_shared_install_options(parser):
+    parser.add_argument('--user', action='store_true', default=None,
+        help="Do a user-local install (default if site.ENABLE_USER_SITE is True)"
+    )
+    parser.add_argument('--env', action='store_false', dest='user',
+        help="Install into sys.prefix (default if site.ENABLE_USER_SITE is False, i.e. in virtualenvs)"
+    )
+    parser.add_argument('--python', default=sys.executable,
+        help="Target Python executable, if different from the one running flit"
+    )
+
+
+def setup(parser):
+    parser.add_argument('-s', '--symlink', action='store_true',
+        help="Symlink the module/package into site packages instead of copying it"
+    )
+    parser.add_argument('--pth-file', action='store_true',
+        help="Add .pth file for the module/package to site packages instead of copying it"
+    )
+    parser.add_argument('--deps', choices=['all', 'production', 'develop', 'none'], default='all',
+        help="Which set of dependencies to install. If --deps=develop, the extras dev, doc, and test are installed"
+    )
+    parser.add_argument('--extras', default=(), type=lambda l: l.split(',') if l else (),
+        help="Install the dependencies of these (comma separated) extras additionally to the ones implied by --deps. "
+             "--extras=all can be useful in combination with --deps=production, --deps=none precludes using --extras"
+    )
+    add_shared_install_options(parser)
+
+
+def run(args):
+    try:
+        Installer(args.ini_file, user=args.user, python=args.python,
+                    symlink=args.symlink, deps=args.deps, extras=args.extras,
+                    pth=args.pth_file).install()
+    except (common.NoDocstringError, common.NoVersionError) as e:
+        return e.args[0]
+    return 0
diff --git a/flit/subcommand/installfrom.py b/flit/subcommand/installfrom.py
new file mode 100644
index 00000000..4b0a167a
--- /dev/null
+++ b/flit/subcommand/installfrom.py
@@ -0,0 +1,24 @@
+"""
+This module contains the implementation of the "installfrom" subcommand.
+"""
+
+import sys
+
+from ..installfrom import installfrom
+from .install import add_shared_install_options
+
+NAME = 'installfrom'
+HELP = "Download and install a package using flit from source"
+
+
+def setup(parser):
+    parser.add_argument(
+        'location',
+        help="A URL to download, or a shorthand like github:takluyver/flit"
+    )
+    add_shared_install_options(parser)
+
+
+def run(args):
+    returncode = installfrom(args.location, user=args.user, python=args.python)
+    return returncode
diff --git a/flit/subcommand/publish.py b/flit/subcommand/publish.py
new file mode 100644
index 00000000..e92c97f5
--- /dev/null
+++ b/flit/subcommand/publish.py
@@ -0,0 +1,18 @@
+"""
+This module contains the implementation of the "installfrom" subcommand.
+"""
+from ..upload import main
+
+NAME = 'publish'
+HELP = "Upload wheel and sdist"
+
+
+def setup(parser):
+    parser.add_argument('--format', action='append',
+                        help="Select a format to publish. Options: 'wheel', 'sdist'"
+                        )
+
+
+def run(args):
+    main(args.ini_file, args.repository, formats=set(args.format or []))
+    return 0
diff --git a/tests/test_command.py b/tests/test_command.py
index 1cec17da..127116e7 100644
--- a/tests/test_command.py
+++ b/tests/test_command.py
@@ -1,5 +1,8 @@
+from flit.common import VCSError, NoVersionError, NoDocstringError
 from subprocess import Popen, PIPE, STDOUT
+from unittest.mock import patch, MagicMock
 import sys
+import pytest
 
 def test_flit_help():
     p = Popen([sys.executable, '-m', 'flit', '--help'], stdout=PIPE, stderr=STDOUT)
@@ -11,3 +14,126 @@ def test_flit_usage():
     out, _ = p.communicate()
     assert 'Build wheel' in out.decode('utf-8', 'replace')
     assert p.poll() == 1
+
+def test_flit_version():
+    import flit
+    version = flit.__version__
+
+    p = Popen([sys.executable, '-m', 'flit', 'info', '--version'],
+               stdout=PIPE, stderr=PIPE)
+    out, _ = p.communicate()
+    assert out.decode('utf-8', 'replace').strip() == version
+
+
+def test_flit_init():
+    from flit.subcommand import init
+    with patch('flit.subcommand.init.TerminalIniter') as ptch:
+        exitcode = init.run(None)
+        ptch().initialise.assert_called_with()
+        assert exitcode == 0
+
+
+def test_flit_build():
+    from flit.subcommand import build
+    mock_args = MagicMock(ini_file='foo', format='bar')
+    with patch('flit.subcommand.build.main') as ptch:
+        exitcode = build.run(mock_args)
+        ptch.assert_called_with('foo', formats=set('bar'))
+        assert exitcode == 0
+
+
+@pytest.mark.parametrize('error_instance', [
+    NoDocstringError('whoops'),
+    VCSError('whoops', 'dirname'),
+    NoVersionError('whoops'),
+])
+def test_flit_build_error(error_instance):
+    from flit.subcommand import build
+    mock_args = MagicMock(ini_file='foo', format='bar')
+    with patch('flit.subcommand.build.main') as ptch:
+        ptch.side_effect = error_instance
+        exitcode = build.run(mock_args)
+        assert exitcode != 0
+
+
+def test_flit_install():
+    from flit.subcommand import install
+    # Set up simple sentinels. We don't care about the type. We only want to
+    # make sure the correct argument-parser values are passed to the correct
+    # constructor args.
+    mock_args = MagicMock(
+        ini_file='inifile',
+        user='user',
+        python='python',
+        symlink='symlink',
+        deps='deps',
+        extras='extras',
+        pth_file='pth',
+    )
+    with patch('flit.subcommand.install.Installer') as ptch:
+        exitcode = install.run(mock_args)
+        ptch.assert_called_with(
+            'inifile',
+            user='user',
+            python='python',
+            symlink='symlink',
+            deps='deps',
+            extras='extras',
+            pth='pth'
+        )
+        ptch().install.assert_called_with()
+        assert exitcode == 0
+
+
+@pytest.mark.parametrize('error_instance', [
+    NoDocstringError('whoops'),
+    NoVersionError('whoops')
+])
+def test_flit_install_error(error_instance):
+    from flit.subcommand import install
+    mock_args = MagicMock(ini_file='foo', format='bar')
+    with patch('flit.subcommand.install.Installer') as ptch:
+        ptch.side_effect = error_instance
+        exitcode = install.run(mock_args)
+        assert exitcode != 0
+
+
+def test_flit_installfrom():
+    from flit.subcommand import installfrom
+    # Set up simple sentinels. We don't care about the type. We only want to
+    # make sure the correct argument-parser values are passed to the correct
+    # constructor args.
+    mock_args = MagicMock(
+        location='location',
+        user='user',
+        python='python',
+    )
+    with patch('flit.subcommand.installfrom.installfrom') as ptch:
+        ptch.return_value = 0
+        exitcode = installfrom.run(mock_args)
+        ptch.assert_called_with(
+            'location',
+            user='user',
+            python='python',
+        )
+        assert exitcode == 0
+
+
+def test_flit_publish():
+    from flit.subcommand import publish
+    # Set up simple sentinels. We don't care about the type. We only want to
+    # make sure the correct argument-parser values are passed to the correct
+    # constructor args.
+    mock_args = MagicMock(
+        ini_file='ini_file',
+        repository='repository',
+        format='format',
+    )
+    with patch('flit.subcommand.publish.main') as ptch:
+        exitcode = publish.run(mock_args)
+        ptch.assert_called_with(
+            'ini_file',
+            'repository',
+            formats=set('format')
+        )
+        assert exitcode == 0