Plankton Code Quality

Plankton Code Quality

Integration reference for Plankton (credit: @alxfazio), a write-time code quality enforcement system. Plankton runs formatters and linters on every file edit via PostToolUse hooks, then spawns agent subprocesses to fix violations.

When to Use

• Automatic formatting and linting on every file edit (not just at commit time)
• Defense against agents modifying linter configs to pass instead of fixing code
• Tiered model routing for fixes (light model for style, standard for logic, advanced for types)
• Multi-language projects (Python, TypeScript, Shell, YAML, JSON, TOML, Markdown, Dockerfile)

Three-Phase Architecture

Every time an agent edits or writes a file, Plankton's multi_linter.sh PostToolUse hook runs:

Phase 1: Auto-Format (Silent)
├─ Runs formatters (ruff format, biome, shfmt, taplo, markdownlint)
├─ Fixes 40–50% of issues silently
└─ No output to main agent

Phase 2: Collect Violations (JSON)
├─ Runs linters and collects unfixable violations
├─ Returns structured JSON: {line, column, code, message, linter}
└─ Still no output to main agent

Phase 3: Delegate + Verify
├─ Spawns subprocess with violations JSON
├─ Routes to model tier based on violation complexity:
│   ├─ Light: formatting, imports, style — 120s timeout
│   ├─ Standard: complexity, refactoring — 300s timeout
│   └─ Advanced: type system, deep reasoning — 600s timeout
├─ Re-runs Phase 1+2 to verify fixes
└─ Exit 0 if clean, Exit 2 if violations remain (reported to main agent)

What the Main Agent Sees

Most quality problems are resolved transparently.

Config Protection

Agents may modify linter configs to disable rules rather than fix code. Plankton blocks this with:

1. PreToolUse hook — protect_linter_configs.sh blocks edits to linter configs before they happen
2. Stop hook — stop_config_guardian.sh detects config changes via git diff at session end
3. Protected files — .ruff.toml, biome.json, .shellcheckrc, .yamllint, .hadolint.yaml, etc.

Package Manager Enforcement

A PreToolUse hook on Bash blocks legacy package managers:

• pip, pip3, poetry, pipenv → blocked (use uv)
• npm, yarn, pnpm → blocked (use bun)
• Exceptions: npm audit, npm view, npm publish

Setup

# Clone Plankton (credit: @alxfazio)
git clone https://github.com/alexfazio/plankton.git
cd plankton

# Install core dependencies
brew install jaq ruff uv

# Install Python linters
uv sync --all-extras

Hooks in .claude/settings.json activate automatically.

Per-Project Integration

1. Copy .claude/hooks/ directory to your project
2. Copy .claude/settings.json hook configuration
3. Copy linter config files (.ruff.toml, biome.json, etc.)
4. Install the linters for your languages

Language Dependencies

Configuration Reference

Plankton's .claude/hooks/config.json controls all behavior:

{
  "languages": {
    "python": true,
    "shell": true,
    "yaml": true,
    "json": true,
    "toml": true,
    "dockerfile": true,
    "markdown": true,
    "typescript": {
      "enabled": true,
      "js_runtime": "auto",
      "biome_nursery": "warn",
      "semgrep": true
    }
  },
  "phases": {
    "auto_format": true,
    "subprocess_delegation": true
  },
  "subprocess": {
    "tiers": {
      "light":    { "timeout": 120, "max_turns": 10 },
      "standard": { "timeout": 300, "max_turns": 10 },
      "advanced": { "timeout": 600, "max_turns": 15 }
    },
    "volume_threshold": 5
  }
}

Key settings:

• Disable unused languages to speed up hooks
• volume_threshold — violations above this count auto-escalate to a higher model tier
• subprocess_delegation: false — skip Phase 3, just report violations

Environment Overrides

References

• Plankton (credit: @alxfazio)