Tiered Audit

---
name: tiered-audit
description: Runs a three-tier codebase audit (git history, targeted scans, full review) with gating. Use when auditing a codebase before release or after incidents.
alwaysApply: false
category: audit
tags:
  - audit
  - git-history
  - code-quality
  - review
  - escalation
tools: []
usage_patterns:
  - codebase-audit
  - git-history-review
  - targeted-review
complexity: intermediate
model_hint: standard
estimated_tokens: 600
modules:
  - modules/escalation-criteria.md
  - modules/tier2-targeted.md
  - modules/tier3-gate.md
dependencies:
  - imbue:proof-of-work
  - imbue:review-core
  - imbue:structured-output
---
# Tiered Audit

## When To Use

- Auditing codebase quality, patterns, or problems
- Reviewing what changed on a branch before merge
- Investigating areas of instability or churn
- Pre-PR quality assessment

## When NOT to Use

- Reviewing a specific file (use pensive:code-reviewer)
- Architecture-only review (use pensive:architecture-review)
- Single-commit review (use imbue:diff-analysis)

## Tier 1: Git History Audit

**Always runs first.** Analyzes git log, diff stats, and
blame to identify areas of concern without reading any
source files.

### What Tier 1 Analyzes

Run the Tier 1 script for the target commit range (default:
current branch against the trunk):

```bash
python3 "${CLAUDE_PLUGIN_ROOT}/scripts/tiered_audit.py" --base {base}
python3 "${CLAUDE_PLUGIN_ROOT}/scripts/tiered_audit.py" --base {base} --json
```

It runs four git queries (file churn, fix-on-fix commit
subjects, per-commit diff size, newly added files), applies
the thresholds in `pensive.skills.tiered_audit` (3+ files in
a module with one changed more than twice, 200+ changed lines
in one commit, 5+ new files in a module), and prints each
flag beside the `[E{n}] Command:` that produced it, so the
findings file can cite the evidence verbatim. `--json` adds
`escalation_targets` and an `escalate` verdict for Tier 2.

**Verification:** an empty report on a branch you know is
busy means the range is wrong. Check that `{base}` resolves
with `git merge-base {base} HEAD` before trusting a quiet
result.

### Tier 1 Output Format

Write findings to `.coordination/agents/tier1-audit.findings.md`:

```markdown
---
agent: tier1-audit
tier: 1
evidence_count: {N}
---

## Summary

{1-2 sentence overview of what the git history reveals}

## Churn Hotspots

{top 10 most-changed files with change counts}

For each flagged file, include:
- Location: path/to/file.py:line (most-changed function or block)
- Anchor: `verbatim source text at that line`

[E1] Command: git log --format="" --name-only ...
     Output: {relevant output}

## Fix-on-Fix Patterns

{commits that fix previous commits in the same area}

[E2] Command: git log --oneline ... | grep -iE ...
     Output: {relevant output}

## New File Clusters

{modules with 5+ new files}

## Large Diffs

{commits with 200+ line changes}

## Escalation Recommendation

{list of areas flagged for Tier 2, or "no escalation needed"}
```

### Escalation Decision

After Tier 1 completes, check findings against the
escalation criteria in `modules/escalation-criteria.md`.

If NO criteria are met: audit is complete. Report findings.

If criteria ARE met: list flagged areas and proceed to
Tier 2 for each area sequentially.

## Tier 2: Targeted Area Audit

**Runs only for areas flagged by Tier 1.**
Each flagged area is audited one at a time, not in
parallel.

### What Tier 2 Analyzes

For each flagged area:

1. Read the source files in the area
2. Check for patterns, anti-patterns, bugs
3. Verify test coverage exists
4. Check documentation currency
5. Assess architectural fit

### Tier 2 Output Format

One findings file per area:
`.coordination/agents/tier2-{area-name}.findings.md`

Each file follows the output contract for audits
(see imbue:proof-of-work/modules/output-contracts).

## Tier 3: Full Codebase Audit

**Requires explicit user approval.** See
`modules/escalation-criteria.md` for the gate protocol.

Tier 3 should use dedicated sessions (one per area)
with file-based coordination, NOT parallel subagents.

## Output Contract

All tiers use this contract:

```yaml
output_contract:
  required_sections:
    - summary
    - evidence
  min_evidence_count: 3    # Tier 1
  # min_evidence_count: 8  # Tier 2
  expected_artifacts: []
  retry_budget: 1
  strictness: normal
```

Tier 2 raises the minimum evidence count to 8 because
it reads source files and should produce deeper analysis.

**Verification:** After each tier completes, verify the
findings file exists and contains at least the minimum
evidence count (`[E1]`, `[E2]`, etc.) before proceeding
to the next tier or reporting results.

### Verify Findings Are Grounded (`tiered-audit:findings-verified`)

Write findings to `.review/findings.json`, run the citation verifier
(`Skill(imbue:review-core)` Step 5), and drop or label `UNVERIFIED` any
the verifier rejects.

## Exit Criteria

- [ ] Tier 1 findings file exists at
      `.coordination/agents/tier1-audit.findings.md` and contains
      at least 3 evidence entries (`[E1]`–`[E3]`).
- [ ] Tier 2 is only started for areas explicitly flagged by Tier 1
      escalation criteria.
- [ ] Every reported finding carries a `Location` + verbatim `Anchor`
      confirmed by `citation_verifier.py` (exit `0`), or unverified
      findings were dropped or labeled `UNVERIFIED`.