Agent Skills: Python Packaging Static Audit

Python Packaging Static Audit

Runs hexora static analysis on a Python package repository to detect suspicious code patterns such as code execution, encoding/serialization, and native code usage. Produces a self-contained "Hexora Static Analysis" report section with triaged findings and a risk assessment.

Inputs

• repo_path (required): Local filesystem path to an already-cloned repository
• output_file (optional): Write the report section to this file path instead of returning it inline. The first line of the file must be RISK_RATING:<value> so the orchestrator can parse it without reading the full report.
• hexora_results (optional): File path to pre-computed hexora JSON output (hexora-results.json). Schema: {status, total, findings[]}. When provided, skip running run-hexora.sh and parse this file directly for triage. Status values: "success", "unavailable", "timeout", "error".

Step 1: Obtain Hexora Results

Option A - Pre-computed results (CI mode)

If hexora_results is provided and the file exists, read and parse it as JSON:

• If status is "success": use the findings array as the hexora output. Each entry is a raw hexora JSONL object (rule, severity, file, line, etc.). Rules HX1000, HX1020, HX1030, HX3010, HX3040, HX5000-HX5050, HX6020-HX6060, HX7000-HX7020 are already excluded by the CI runner; minimum confidence is medium. Proceed directly to Step 2 (Triage).
• If status is "unavailable", "timeout", or "error": skip to the Output section and produce the report with risk_rating = needs_review, noting the degraded status and any error message from the JSON. Do not re-run hexora. The CI runner already attempted execution under controlled conditions, and re-running in the agent container would likely hit the same failure.
• For any other status value not listed above: treat it as an error and report risk_rating = needs_review, noting the unrecognized status value.

Option B - Run hexora locally (standalone mode)

If hexora_results is not provided, run the wrapper script which handles hexora installation and applies the tuned rule exclusions:

./scripts/run-hexora.sh <repo-path>
hexora_exit=$?

Check the exit code before proceeding:

• Exit 0: hexora ran successfully. Capture the JSON output. Each finding contains: rule code, file path, line number, confidence level, and description.
• Exit 2: hexora is not installed and cannot be auto-installed via uvx. Do not fail. Skip to the Output section and produce the report with risk_rating = needs_review stating hexora was unavailable.
• Exit 1: hexora encountered a runtime error. Skip to the Output section and produce the report with risk_rating = needs_review noting the error.

The wrapper filters out rules that are too noisy for typical Python packages and sets a minimum confidence of medium. See the script comments for the full exclusion list and rationale.

Step 2: Triage

Review hexora findings in context. Read the relevant source files to understand the purpose of flagged code. Triage proceeds in two stages: deterministic rules first, then AI reasoning for anything unresolved.

Stage 1 — Deterministic Rules

Apply the following rules before any AI reasoning. These handle the most common clear-cut cases and make the triage reproducible.

| Condition | Verdict | |-----------|---------| | Finding is in a file under test/, tests/, benchmarks/, or examples/ | PASS | | Finding references a standard-library import already excluded by run-hexora.sh rule set | PASS | | Finding is in setup.py, setup.cfg, or pyproject.toml and involves eval, exec, compile, base64, or marshal | REVIEW |

When multiple findings produce different verdicts, the overall precedence is BLOCK > REVIEW > PASS — the most severe verdict wins.

Any finding not resolved by Stage 1 proceeds to Stage 2.

Stage 2 — AI Reasoning

For findings that remain unresolved after deterministic rules, classify each as:

• Likely legitimate — pattern is expected for the package's purpose (e.g., subprocess in a CLI tool)
• Suspicious — pattern is unusual and warrants manual review (e.g., base64 decode in setup.py)
• Critical — pattern strongly indicates malicious intent (e.g., network exfiltration in install hooks)

Output Format

Produce the following markdown section:

## Hexora Static Analysis

**Findings:** {N total} ({X critical, Y suspicious, Z likely legitimate})

### Critical Findings

| File | Line | Rule | Confidence | Description | Triage |
|------|------|------|------------|-------------|--------|
| setup.py | 42 | HX2000 | Very High | Base64 decode in install hook | Suspicious — no legitimate reason for encoded payloads in setup.py |

### Suspicious Findings

(same table format)

### Likely Legitimate

(same table format, brief — included for completeness but de-emphasized)

The risk_rating for this phase is one of:

• no_issues — No hexora findings
• low_risk — All findings classified as "likely legitimate" or PASS
• needs_review — One or more findings classified as "suspicious" or REVIEW
• critical — One or more findings classified as "critical" or BLOCK

If output_file is provided, write the file with the first line as RISK_RATING:<value> followed by a blank line and then the markdown section above. If output_file is not provided, return the report section inline.

Error Handling

| Scenario | Behavior | |----------|----------| | Hexora returns empty results | Report "no findings" for hexora section, risk_rating = no_issues | | Hexora is unavailable (uvx and hexora both missing) | Report hexora unavailable, risk_rating = needs_review | | Pre-computed hexora_results file path provided but file missing, unreadable, or invalid JSON | Report hexora unavailable, risk_rating = needs_review | | Pre-computed hexora_results has degraded status (unavailable/timeout/error) | Do not re-run hexora; report the degraded status, risk_rating = needs_review |