Tiered Audit

---
name: tiered-audit
description: |
  Audit a codebase using a three-tier escalation model.
  Tier 1 analyzes git history (fast, bounded).
  Tier 2 deep-dives into flagged areas (sequential).
  Tier 3 reviews the full codebase (requires approval).
  Always starts at Tier 1 unless explicitly overridden.
category: audit
tags:
  - audit
  - git-history
  - code-quality
  - review
  - escalation
tools:
  - Bash
  - Read
  - Grep
  - Glob
usage_patterns:
  - codebase-audit
  - git-history-review
  - targeted-review
complexity: intermediate
estimated_tokens: 600
modules:
  - modules/escalation-criteria.md
  - modules/tier2-targeted.md
  - modules/tier3-gate.md
dependencies:
  - imbue:proof-of-work
---

# 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 these git commands for the target commit range
(default: current branch vs main):

```bash
# 1. Churn hotspots: files changed most often
git log --format="" --name-only {base}..HEAD \
  | sort | uniq -c | sort -rn | head -20

# 2. Diff stats: size of changes per file
git diff --stat {base}..HEAD

# 3. Fix-on-fix patterns: commits fixing previous commits
git log --oneline {base}..HEAD \
  | grep -iE "(fix|revert|patch|hotfix)"

# 4. New file clusters: modules with many new files
git diff --name-status {base}..HEAD \
  | grep "^A" | cut -f2 \
  | sed 's|/[^/]*$||' | sort | uniq -c | sort -rn

# 5. Large commits: single commits with big diffs
git log --format="%h %s" --shortstat {base}..HEAD
```

### 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}

[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.