Plugin Validator

Comprehensive validation for Claude Code marketplace plugins.

Self-Evolving Skill: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues.

When to Use This Skill

Use this skill when:

• Validating plugin structure before release
• Auditing hooks for silent failures
• Checking plugin.json syntax and required fields
• Verifying skill file formatting and frontmatter

Quick Start

# Validate a specific plugin
uv run plugins/plugin-dev/skills/plugin-validator/scripts/audit_silent_failures.py plugins/my-plugin/

# Validate with fix suggestions
uv run plugins/plugin-dev/skills/plugin-validator/scripts/audit_silent_failures.py plugins/my-plugin/ --fix

Validation Phases

Phase 1: Structure Validation

Check plugin directory structure:

/usr/bin/env bash << 'VALIDATE_EOF'
PLUGIN_PATH="${1:-.}"

# Check plugin.json exists
if [[ ! -f "$PLUGIN_PATH/plugin.json" ]]; then
    echo "ERROR: Missing plugin.json" >&2
    exit 1
fi

# Validate JSON syntax
if ! jq empty "$PLUGIN_PATH/plugin.json" 2>/dev/null; then
    echo "ERROR: Invalid JSON in plugin.json" >&2
    exit 1
fi

# Check required fields
REQUIRED_FIELDS=("name" "version" "description")
for field in "${REQUIRED_FIELDS[@]}"; do
    if ! jq -e ".$field" "$PLUGIN_PATH/plugin.json" >/dev/null 2>&1; then
        echo "ERROR: Missing required field: $field" >&2
        exit 1
    fi
done

echo "Structure validation passed"
VALIDATE_EOF

Phase 2: Silent Failure Audit

Critical Rule: All hook entry points MUST emit to stderr on failure.

Run the audit script:

uv run plugins/plugin-dev/skills/plugin-validator/scripts/audit_silent_failures.py plugins/my-plugin/

What Gets Checked

Check	Target Files	Pattern
Shellcheck	hooks/*.sh	SC2155, SC2086, etc.
Silent bash	hooks/*.sh	mkdir|cp|mv|rm|jq without if !
Silent Python	hooks/*.py	except.*: pass without stderr

Hook Entry Points vs Utility Scripts

Location	Type	Requirement
plugins/*/hooks/*.sh	Entry point	MUST emit to stderr
plugins/*/hooks/*.py	Entry point	MUST emit to stderr
plugins/*/scripts/*.sh	Utility	Fallback behavior OK
plugins/*/scripts/*.py	Utility	Fallback behavior OK

Phase 3: Fix Patterns

Bash: Silent mkdir

# BAD - silent failure
mkdir -p "$DIR"

# GOOD - emits to stderr
if ! mkdir -p "$DIR" 2>&1; then
    echo "[plugin] Failed to create directory: $DIR" >&2
fi

Python: Silent except pass

# BAD - silent failure
except (json.JSONDecodeError, OSError):
    pass

# GOOD - emits to stderr
except (json.JSONDecodeError, OSError) as e:
    print(f"[plugin] Warning: {e}", file=sys.stderr)

Integration with /plugin-dev:create

This skill is invoked in Phase 3 of the plugin-add workflow:

### 3.4 Plugin Validation

**MANDATORY**: Run plugin-validator before registration.

Task with subagent_type="plugin-dev:plugin-validator"
prompt: "Validate the plugin at plugins/$PLUGIN_NAME/"

Exit Codes

Code	Meaning
0	All validations passed
1	Violations found (see output)
2	Error (invalid path, missing files)

References

• Silent Failure Patterns

Troubleshooting

Issue	Cause	Solution
plugin.json not found	Missing manifest file	Create plugin.json with required fields
Invalid JSON syntax	Malformed plugin.json	Run jq empty plugin.json to find syntax errors
Missing required field	Incomplete manifest	Add name, version, description to plugin.json
Shellcheck errors	Bash script issues	Run shellcheck hooks/*.sh to see details
Silent failure in bash	Missing error handling	Add if ! check around mkdir/cp/mv/rm commands
Silent except:pass in Python	Missing stderr output	Add print(..., file=sys.stderr) before pass
Exit code 2	Invalid path or missing files	Verify plugin path exists and has correct structure
Violations after --fix	Fix suggestions not applied	Manually apply suggested fixes from output

Post-Execution Reflection

After this skill completes, reflect before closing the task:

0. Locate yourself. — Find this SKILL.md's canonical path (Glob for this skill's name) before editing. All corrections target THIS file and its sibling references/ — never other documentation.
1. What failed? — Fix the instruction that caused it. If it could recur, add it as an anti-pattern.
2. What worked better than expected? — Promote it to recommended practice. Document why.
3. What drifted? — Any script, reference, or external dependency that no longer matches reality gets fixed now.
4. Log it. — Every change gets an evolution-log entry with trigger, fix, and evidence.

Do NOT defer. The next invocation inherits whatever you leave behind.

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