By the numbers

Data collected on 2026-04-30 from the devel branch at commit ff6b7e404a.

Size

The tree is overwhelmingly Python, with small but important pieces of PowerShell and C# for Windows targets, and a large body of YAML used for configuration, integration-test fixtures, and changelog fragments.

xychart-beta horizontal
    title "Source files by language (lib/ + test/)"
    x-axis ["Python (lib)", "Python (test)", "YAML", "PowerShell", "C#"]
    y-axis "Files" 0 --> 2200
    bar [583, 1213, 2042, 24, 6]

Layer	Size
lib/ (controller code, modules, plugins, module_utils)	8.2 MB across 583 Python files
test/ (unit + integration + ansible-test tooling)	25 MB across 1213 Python files
Total Python lines under lib/	~136,000
YAML files (excluding .git/)	2,042
PowerShell files (.ps1 + .psm1)	24
C# files	6

Largest source files

The biggest single files are concentrated in the controller hot path and a few sprawling modules.

File	Lines
lib/ansible/modules/user.py	3,564
lib/ansible/module_utils/basic.py	2,219
lib/ansible/galaxy/collection/__init__.py	1,933
lib/ansible/plugins/loader.py	1,905
lib/ansible/cli/galaxy.py	1,889
lib/ansible/executor/module_common.py	1,694
lib/ansible/cli/doc.py	1,676
lib/ansible/module_utils/urls.py	1,639
lib/ansible/plugins/connection/ssh.py	1,625
lib/ansible/_internal/_templating/_jinja_bits.py	1,500+

Several of these are surfaced again in Cleanup opportunities → Complexity hotspots (when present) — they are natural targets for further decomposition.

Activity

Metric	Value
Total commits in the repo	~55,400
Commits in the last 90 days	~119
First commit	2012-02-23 ("Genesis." by Michael DeHaan)
Most recent commit on devel	2026-04-30
Unique authors (over project lifetime)	6,433

The recent-90-day churn is concentrated in a small set of files, suggesting where current development effort is going.

Source path	Commits in last 90 days
lib/ansible/config/base.yml	8
lib/ansible/modules/user.py	7
lib/ansible/plugins/action/__init__.py	6
lib/ansible/plugins/connection/psrp.py	4
lib/ansible/module_utils/urls.py	4
lib/ansible/module_utils/csharp/Ansible.Basic.cs	4
lib/ansible/plugins/connection/winrm.py	3
lib/ansible/plugins/connection/ssh.py	3
lib/ansible/modules/find.py	3
lib/ansible/modules/apt.py	3
lib/ansible/galaxy/collection/concrete_artifact_manager.py	3
lib/ansible/galaxy/collection/__init__.py	3
lib/ansible/executor/task_executor.py	3
lib/ansible/executor/module_common.py	3
lib/ansible/_internal/_powershell/_clixml.py	3

The hot files are mostly the connection layer (PowerShell remoting, SSH), the URL utilities, the user module, and the action plugin base — areas with active platform support and bug-fixing.

Bot-attributed commits

Searching the git log on devel:

• Commits whose author/committer email ends in [bot]: 0
• Co-authored-by: trailers naming a bot: 1

ansible-core is a long-standing project with a strong human-authorship culture; the README explicitly states "This project is substantially coded by humans." Bot-attributed work is essentially absent. Note that this is a lower bound on AI-assisted contribution since inline tooling like Copilot does not leave git-history traces.

Test-to-code ratio

Counting Python files only:

• lib/: 583 files
• test/: 1,213 files

A 2.08-to-1 test-to-source ratio. Integration-test targets under test/integration/targets/ make up most of test/ by volume and contain hundreds of YAML playbooks alongside the Python.

Plugin and module counts

Category	Count
Plugin types under lib/ansible/plugins/	17 (action, become, cache, callback, cliconf, connection, doc_fragments, filter, httpapi, inventory, lookup, netconf, shell, strategy, terminal, test, vars)
Built-in modules under lib/ansible/modules/	73
End-user CLIs (excluding ansible-test)	9 (ansible, ansible-config, ansible-console, ansible-doc, ansible-galaxy, ansible-inventory, ansible-playbook, ansible-pull, ansible-vault)
Connection plugins	4 (local, ssh, winrm, psrp)
Become plugins	3 (sudo, su, runas)
Strategy plugins	4 (linear, free, host_pinned, debug)
Inventory plugins	9 (advanced_host_list, auto, constructed, generator, host_list, ini, script, toml, yaml)
Callback plugins	5 (default, minimal, oneline, junit, tree)

Releases

The first tagged Ansible 2.x release with a fully-public commit history is v2.5.0 in March 2018. Major minor versions since then:

Tag	Date
v2.5.0	2018-03-22
v2.6.0	2018-06-28
v2.7.0	2018-10-03
v2.8.0	2019-05-16
v2.9.0	2019-10-31
v2.10.0	2020-08-13
v2.11.0	2021-04-26
v2.12.0	2021-11-08
v2.13.0	2022-05-16
v2.14.0	2022-11-07
v2.15.0	2023-05-15
v2.16.0	2023-11-06
v2.17.0	2024-05-20
v2.18.0	2024-11-04
v2.19.0	2025-07-21
v2.20.0	2025-11-04

Release cadence settled into approximately twice a year (May and November) starting with the 2.13 line. The current devel branch identifies as 2.22.0.dev0 per lib/ansible/release.py.

Complexity

A handful of "god files" carry an outsized share of the controller's complexity:

File	Lines	Notes
lib/ansible/module_utils/basic.py	2,219	The remote-side AnsibleModule class: argument parsing, run-time, file/permissions helpers, no-log scrubbing
lib/ansible/plugins/loader.py	1,905	Generic plugin loader, collection name redirects, deprecation handling
lib/ansible/executor/module_common.py	1,694	AnsiBallZ assembly: AST scanning of imports, dependency walk, archive build
lib/ansible/_internal/_task.py	1,444	Internal task representation used across the worker boundary
lib/ansible/_internal/_wrapt.py	1,015	Vendored wrapt proxy primitives — large but stable
lib/ansible/plugins/connection/ssh.py	1,625	The default connection: ssh + sftp + scp + sshpass + reverse-tunnels + ControlMaster

All controller code uses from __future__ import annotations, so type hints are strings at runtime. The line limit is 160 (not 80) per AGENTS.md.

Languages and platforms

ansible-core is Python-first and POSIX-only on the controller, but supports Windows targets through:

• PowerShell modules (lib/ansible/modules/setup.ps1 is symlinked or generated at build time; most Windows modules live in collections like ansible.windows).
• The winrm and psrp connection plugins.
• Compiled-on-the-fly C# helpers under lib/ansible/module_utils/csharp/.

TODO/FIXME backlog

A literal grep for TODO|FIXME|XXX|HACK across lib/ansible/ matches roughly 359 occurrences. This is a rough proxy for accumulated technical debt; the bulk live in module_utils/basic.py, plugins/loader.py, and the older module_utils files that handle distro-specific quirks.