diff --git a/codebasin/coverage/__init__.py b/codebasin/coverage/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/codebasin/coverage/__main__.py b/codebasin/coverage/__main__.py
index 63971b5..c7d5359 100755
--- a/codebasin/coverage/__main__.py
+++ b/codebasin/coverage/__main__.py
@@ -12,26 +12,56 @@
 from codebasin import CodeBase, config, finder, util
 
 # TODO: Refactor to avoid imports from __main__
-from codebasin.__main__ import Formatter, WarningAggregator, _help_string
+from codebasin.__main__ import (
+    Formatter,
+    WarningAggregator,
+    _help_string,
+    version,
+)
 from codebasin.preprocessor import CodeNode
 
 log = logging.getLogger("codebasin")
 
 
-def cli(argv: list[str]):
-    # Read command-line arguments
+def _build_parser() -> argparse.ArgumentParser:
+    """
+    Build argument parser.
+    """
     parser = argparse.ArgumentParser(
-        description="Code Base Investigator Coverage Tool",
+        description="CBI Coverage Tool " + version,
         formatter_class=argparse.RawTextHelpFormatter,
         add_help=False,
     )
+    parser.set_defaults(func=None)
     parser.add_argument(
         "-h",
         "--help",
         action="help",
-        help=_help_string("Display help message and exit."),
+        help="Display help message and exit.",
     )
     parser.add_argument(
+        "--version",
+        action="version",
+        version=f"CBI Coverage Tool {version}",
+        help="Display version information and exit.",
+    )
+
+    subparsers = parser.add_subparsers(title="commands")
+
+    compute_parser = subparsers.add_parser(
+        "compute",
+        help="Compute coverage.",
+        formatter_class=argparse.RawTextHelpFormatter,
+        add_help=False,
+    )
+    compute_parser.set_defaults(func=_compute)
+    compute_parser.add_argument(
+        "-h",
+        "--help",
+        action="help",
+        help=_help_string("Display help message and exit."),
+    )
+    compute_parser.add_argument(
         "-S",
         "--source-dir",
         metavar="<path>",
@@ -39,7 +69,7 @@ def cli(argv: list[str]):
         help=_help_string("Path to source directory.", is_long=True),
         default=os.getcwd(),
     )
-    parser.add_argument(
+    compute_parser.add_argument(
         "-x",
         "--exclude",
         dest="excludes",
@@ -50,21 +80,34 @@ def cli(argv: list[str]):
             "Exclude files matching this pattern from the code base.",
             "May be specified multiple times.",
             is_long=True,
+        ),
+    )
+    compute_parser.add_argument(
+        "-o",
+        "--output",
+        dest="ofile",
+        metavar="<output path>",
+        default="coverage.json",
+        help=_help_string(
+            "Path to coverage JSON file.",
+            "If not specified, defaults to 'coverage.json'.",
+            is_long=True,
             is_last=True,
         ),
     )
-    parser.add_argument(
+    compute_parser.add_argument(
         "ifile",
         metavar="<input path>",
-        help=_help_string("Path to compilation database JSON file."),
-    )
-    parser.add_argument(
-        "ofile",
-        metavar="<output path>",
-        help=_help_string("Path to coverage JSON file.", is_last=True),
+        help=_help_string(
+            "Path to compilation database JSON file.",
+            is_last=True,
+        ),
     )
-    args = parser.parse_args(argv)
 
+    return parser
+
+
+def _compute(args: argparse.Namespace):
     dbpath = os.path.realpath(args.ifile)
     covpath = os.path.realpath(args.ofile)
     for path in [dbpath, covpath]:
@@ -75,29 +118,6 @@ def cli(argv: list[str]):
 
     source_dir = os.path.realpath(args.source_dir)
 
-    # Configure logging such that:
-    # - All messages are written to a log file
-    # - Only errors are written to the terminal
-    # - Meta-warnings and statistics are generated by a WarningAggregator
-    aggregator = WarningAggregator()
-    log.setLevel(logging.DEBUG)
-
-    file_handler = logging.FileHandler("cbi.log", mode="w")
-    file_handler.setLevel(logging.INFO)
-    file_handler.setFormatter(Formatter())
-    file_handler.addFilter(aggregator)
-    log.addHandler(file_handler)
-
-    # Inform the user that a log file has been created.
-    # 'print' instead of 'log' to ensure the message is visible in the output.
-    log_path = os.path.abspath("cbi.log")
-    print(f"Log file created at {log_path}")
-
-    stderr_handler = logging.StreamHandler(sys.stderr)
-    stderr_handler.setLevel(logging.ERROR)
-    stderr_handler.setFormatter(Formatter(colors=sys.stderr.isatty()))
-    log.addHandler(stderr_handler)
-
     # Run CBI configured as-if:
     # - configuration contains a single (dummy) platform
     # - codebase contains all files in the specified compilation database
@@ -135,6 +155,41 @@ def cli(argv: list[str]):
     sys.exit(0)
 
 
+def cli(argv: list[str]) -> int:
+    parser = _build_parser()
+    args = parser.parse_args(argv)
+    command = args.func
+
+    if command is None:
+        parser.print_help()
+        sys.exit(2)
+
+    # Configure logging such that:
+    # - All messages are written to a log file
+    # - Only errors are written to the terminal
+    # - Meta-warnings and statistics are generated by a WarningAggregator
+    aggregator = WarningAggregator()
+    log.setLevel(logging.DEBUG)
+
+    file_handler = logging.FileHandler("cbi.log", mode="w")
+    file_handler.setLevel(logging.INFO)
+    file_handler.setFormatter(Formatter())
+    file_handler.addFilter(aggregator)
+    log.addHandler(file_handler)
+
+    # Inform the user that a log file has been created.
+    # 'print' instead of 'log' to ensure the message is visible in the output.
+    log_path = os.path.abspath("cbi.log")
+    print(f"Log file created at {log_path}")
+
+    stderr_handler = logging.StreamHandler(sys.stderr)
+    stderr_handler.setLevel(logging.ERROR)
+    stderr_handler.setFormatter(Formatter(colors=sys.stderr.isatty()))
+    log.addHandler(stderr_handler)
+
+    return command(args)
+
+
 def main():
     try:
         cli(sys.argv[1:])