• There are 1,962 files with units, with 776,713 lines of code.
• 8 very complex files (McCabe index sum 251+; 26,337 lines of code)
• 26 complex files (McCabe index sum 126-250; 67,740 lines of code)
• 138 medium complex files (McCabe index sum 51-125; 152,249 lines of code)
• 215 slightly complex files (McCabe index sum 26-50; 133,908 lines of code)
• 1,575 simple files (McCabe index sum 1-25; 396,479 lines of code)
• 1,326 main files have no units (e.g. languages without unit analysis, or files without functions) and are not classified.

The McCabe index of a file grows with its size: per 100 lines tells a large but plain file from a dense one, and most complex unit whether the complexity sits in one unit or is spread over many.

File	# lines	# units	McCabe index (sum)	per 100 lines	most complex unit
export.rs in codex-rs/app-server-protocol/src	2789	107	471	17	53
resume_picker.rs in codex-rs/tui/src	6747	198	426	6	17
markdown_render.rs in codex-rs/tui/src	2872	126	398	14	18
textarea.rs in codex-rs/tui/src/bottom_pane	3877	166	370	10	31
parse_command.rs in codex-rs/shell-command/src	2552	117	341	13	69
mod.rs in codex-rs/tui/src/bottom_pane/request_user_input	3478	153	315	9	49
list_selection_view.rs in codex-rs/tui/src/bottom_pane	2780	111	293	11	44
update_sdk_artifacts.py in sdk/python/scripts	1242	64	258	21	17
main.rs in codex-rs/cli/src	4349	177	246	6	6
doctor.rs in codex-rs/cli/src	2867	91	244	9	16
thread_history.rs in codex-rs/app-server-protocol/src/protocol	5262	130	243	5	11
bwrap.rs in codex-rs/linux-sandbox/src	2746	81	239	9	45
mcp_server_elicitation.rs in codex-rs/tui/src/bottom_pane	2114	87	227	11	20
output.rs in codex-rs/cli/src/doctor	1836	91	213	12	13
credential_broker.rs in codex-rs/network-proxy/src	1564	23	192	12	97
run_codex_compliance.py in scripts/mcp_conformance	2098	48	192	9	37
keymap.rs in codex-rs/tui/src	3597	101	189	5	26
linux_run_main.rs in codex-rs/linux-sandbox/src	1338	59	183	14	8
mod.rs in codex-rs/tui/src/bottom_pane	3511	76	178	5	48
manager.rs in codex-rs/core-plugins/src	3576	57	174	5	27
approval_overlay.rs in codex-rs/tui/src/bottom_pane	2388	80	173	7	14
spec_plan.rs in codex-rs/core/src/tools	1504	31	172	11	26
config_requirements.rs in codex-rs/config/src	4571	104	172	4	25
reducer.rs in codex-rs/analytics/src	3937	96	170	4	15
wrapping.rs in codex-rs/tui/src	1159	39	169	15	21
client.py in sdk/python/src/openai_codex	776	71	156	20	10
plugin_catalog.rs in codex-rs/tui/src/chatwidget	1910	58	155	8	22
diff_render.rs in codex-rs/tui/src	2304	92	151	7	20
permissions.rs in codex-rs/protocol/src	2266	52	150	7	23
controller.rs in codex-rs/tui/src/streaming	1616	66	144	9	9
models.rs in codex-rs/protocol/src	4051	112	135	3	7
hooks_browser_view.rs in codex-rs/tui/src/bottom_pane	1597	72	133	8	13
mod.rs in codex-rs/core/src/config	4152	61	129	3	9
windows_dangerous_commands.rs in codex-rs/shell-command/src/command_safety	651	55	129	20	22
app_link_view.rs in codex-rs/tui/src/bottom_pane	1396	51	123	9	16
slash_dispatch.rs in codex-rs/tui/src/chatwidget	1320	15	123	9	47
methods.rs in codex-rs/codex-api/src/endpoint/realtime_websocket	2979	64	121	4	14
powershell_tree_sitter.rs in codex-rs/shell-command/src/command_safety	434	17	119	27	32
certs.rs in codex-rs/network-proxy/src	1169	44	117	10	11
shell_snapshot_literals.rs in codex-rs/shell-command/src	688	7	117	17	84
status_surfaces.rs in codex-rs/tui/src/chatwidget	1081	43	116	11	9
ipc.rs in codex-rs/tui/src/ide_context	1136	57	115	10	7
highlight.rs in codex-rs/tui/src/render	1383	66	114	8	8
client.rs in codex-rs/core/src	2351	40	112	5	13
codex_conformance_adapter.py in scripts/mcp_conformance	890	27	112	13	34
auth.rs in codex-rs/tui/src/onboarding	1496	38	110	7	13
seatbelt.rs in codex-rs/sandboxing/src	1003	26	110	11	17
mcp_tool_call.rs in codex-rs/core/src	2373	37	109	5	15
setup_provisioning.rs in codex-rs/windows-sandbox-rs/src	1415	28	108	8	32
custom_terminal.rs in codex-rs/tui/src	1085	39	107	10	21

• File complexity is the sum of the McCabe indexes (conditional complexity) of the units (methods, functions...) in a file.
• Files are classified in five categories based on that sum: 1-25 (simple files), 26-50 (slightly complex files), 51-125 (medium complex files), 126-250 (complex files), 251+ (very complex files). The default bands are five times the unit complexity bands, as a file is a group of units.
• Only main code files with units are classified. Files without units (languages without unit analysis, or files without functions) have no complexity to measure and are left out rather than counted as simple.
• A very complex file holds many decisions, which often means it has too many responsibilities: a candidate to split, and a place where changes need more testing.