Security Ownership Map

Overview

Build a bipartite graph of people and files from git history, then compute ownership risk and export graph artifacts for Neo4j/Gephi. Also build a file co-change graph (Jaccard similarity on shared commits) to cluster files by how they move together while ignoring large, noisy commits.

Requirements

Python 3
```
networkx
```
(required; community detection is enabled by default)

Install with:

bash

pip install networkx

Workflow

Scope the repo and time window (optional
```
--since/--until
```
).
Decide sensitivity rules (use defaults or provide a CSV config).
Build the ownership map with
```
scripts/run_ownership_map.py
```
(co-change graph is on by default; use
```
--cochange-max-files
```
to ignore supernode commits).
Communities are computed by default; graphml output is optional (
```
--graphml
```
).
Query the outputs with
```
scripts/query_ownership.py
```
for bounded JSON slices.
Persist and visualize (see
```
references/neo4j-import.md
```
).

By default, the co-change graph ignores common “glue” files (lockfiles,

.github/*

, editor config) so clusters reflect actual code movement instead of shared infra edits. Override with

--cochange-exclude

--no-default-cochange-excludes

. Dependabot commits are excluded by default; override with

--no-default-author-excludes

or add patterns via

--author-exclude-regex

If you want to exclude Linux build glue like

Kbuild

from co-change clustering, pass:

bash

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \
  --repo /path/to/linux \
  --out ownership-map-out \
  --cochange-exclude "**/Kbuild"

Quick start

Run from the repo root:

bash

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \
  --repo . \
  --out ownership-map-out \
  --since "12 months ago" \
  --emit-commits

Defaults: author identity, author date, and merge commits excluded. Use

--identity committer

--date-field committer

, or

--include-merges

if needed.

Example (override co-change excludes):

bash

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \
  --repo . \
  --out ownership-map-out \
  --cochange-exclude "**/Cargo.lock" \
  --cochange-exclude "**/.github/**" \
  --no-default-cochange-excludes

Communities are computed by default. To disable:

bash

python skills/skills/security-ownership-map/scripts/run_ownership_map.py \
  --repo . \
  --out ownership-map-out \
  --no-communities

Sensitivity rules

By default, the script flags common auth/crypto/secret paths. Override by providing a CSV file:

# pattern,tag,weight
**/auth/**,auth,1.0
**/crypto/**,crypto,1.0
**/*.pem,secrets,1.0

Use it with

--sensitive-config path/to/sensitive.csv

Output artifacts

ownership-map-out/

contains:

```
people.csv
```
(nodes: people)
```
files.csv
```
(nodes: files)
```
edges.csv
```
(edges: touches)
```
cochange_edges.csv
```
(file-to-file co-change edges with Jaccard weight; omitted with
```
--no-cochange
```
)
```
summary.json
```
(security ownership findings)
```
commits.jsonl
```
(optional, if
```
--emit-commits
```
)
```
communities.json
```
(computed by default from co-change edges when available; includes
```
maintainers
```
per community; disable with
```
--no-communities
```
)

cochange.graph.json

(NetworkX node-link JSON with

community_id

community_maintainers

; falls back to

ownership.graph.json

if no co-change edges)

ownership.graphml

cochange.graphml

(optional, if

--graphml

)

people.csv

includes timezone detection based on author commit offsets:

primary_tz_offset

primary_tz_minutes

, and

timezone_offsets

LLM query helper

Use

scripts/query_ownership.py

to return small, JSON-bounded slices without loading the full graph into context.

Examples:

bash

python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out people --limit 10
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag auth --bus-factor-max 1
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out person --person alice@corp --limit 10
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out file --file crypto/tls
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out cochange --file crypto/tls --limit 10
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section orphaned_sensitive_code
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out community --id 3

Use

--community-top-owners 5

(default) to control how many maintainers are stored per community.

Basic security queries

Run these to answer common security ownership questions with bounded output:

bash

# Orphaned sensitive code (stale + low bus factor)
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section orphaned_sensitive_code

# Hidden owners for sensitive tags
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section hidden_owners

# Sensitive hotspots with low bus factor
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out summary --section bus_factor_hotspots

# Auth/crypto files with bus factor <= 1
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag auth --bus-factor-max 1
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out files --tag crypto --bus-factor-max 1

# Who is touching sensitive code the most
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out people --sort sensitive_touches --limit 10

# Co-change neighbors (cluster hints for ownership drift)
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out cochange --file path/to/file --min-jaccard 0.05 --limit 20

# Community maintainers (for a cluster)
python skills/skills/security-ownership-map/scripts/query_ownership.py --data-dir ownership-map-out community --id 3

# Monthly maintainers for the community containing a file
python skills/skills/security-ownership-map/scripts/community_maintainers.py \
  --data-dir ownership-map-out \
  --file network/card.c \
  --since 2025-01-01 \
  --top 5

# Quarterly buckets instead of monthly
python skills/skills/security-ownership-map/scripts/community_maintainers.py \
  --data-dir ownership-map-out \
  --file network/card.c \
  --since 2025-01-01 \
  --bucket quarter \
  --top 5

Notes:

Touches default to one authored commit (not per-file). Use
```
--touch-mode file
```
to count per-file touches.

Use

--window-days 90

--weight recency --half-life-days 180

to smooth churn.

Filter bots with

--ignore-author-regex '(bot|dependabot)'

Use
```
--min-share 0.1
```
to show stable maintainers only.
Use
```
--bucket quarter
```
for calendar quarter groupings.

Use

--identity committer

--date-field committer

to switch from author attribution.

Use
```
--include-merges
```
to include merge commits (excluded by default).

Summary format (default)

Use this structure, add fields if needed:

json

{
  "orphaned_sensitive_code": [
    {
      "path": "crypto/tls/handshake.rs",
      "last_security_touch": "2023-03-12T18:10:04+00:00",
      "bus_factor": 1
    }
  ],
  "hidden_owners": [
    {
      "person": "alice@corp",
      "controls": "63% of auth code"
    }
  ]
}

Graph persistence

Use

references/neo4j-import.md

when you need to load the CSVs into Neo4j. It includes constraints, import Cypher, and visualization tips.

Notes

```
bus_factor_hotspots
```
in
```
summary.json
```
lists sensitive files with low bus factor;
```
orphaned_sensitive_code
```
is the stale subset.
If
```
git log
```
is too large, narrow with
```
--since
```
or
```
--until
```
.
Compare
```
summary.json
```
against CODEOWNERS to highlight ownership drift.

security-ownership-map

NPX Install

SKILL.md Content

Security Ownership Map

Overview

Requirements

Workflow

Quick start

Sensitivity rules

Output artifacts

LLM query helper

Basic security queries

Summary format (default)

Graph persistence

Notes