Plugin Settings Pattern for Claude Code Plugins

Plugin Settings Pattern for Claude Code Plugins

Overview

Plugins can store user-configurable settings and state in `.claude/plugin-name.local.md` files within the project directory. This pattern uses YAML frontmatter for structured configuration and markdown content for prompts or additional context.

**Key characteristics:**

• File location: `.claude/plugin-name.local.md` in project root
• Structure: YAML frontmatter + markdown body
• Purpose: Per-project plugin configuration and state
• Usage: Read from hooks, commands, and agents
• Lifecycle: User-managed (not in git, should be in `.gitignore`)

File Structure

Basic Template

---
enabled: true
setting1: value1
setting2: value2
numeric_setting: 42
list_setting: ["item1", "item2"]
---

# Additional Context

This markdown body can contain:
- Task descriptions
- Additional instructions
- Prompts to feed back to Claude
- Documentation or notes

Example: Plugin State File

**.claude/my-plugin.local.md:**

---
enabled: true
strict_mode: false
max_retries: 3
notification_level: info
coordinator_session: team-leader
---

# Plugin Configuration

This plugin is configured for standard validation mode.
Contact @team-lead with questions.

Reading Settings Files

From Hooks (Bash Scripts)

**Pattern: Check existence and parse frontmatter**

#!/bin/bash
set -euo pipefail

# Define state file path
STATE_FILE=".claude/my-plugin.local.md"

# Quick exit if file doesn't exist
if [[ ! -f "$STATE_FILE" ]]; then
  exit 0  # Plugin not configured, skip
fi

# Parse YAML frontmatter (between --- markers)
FRONTMATTER=$(sed -n '/^---$/,/^---$/{ /^---$/d; p; }' "$STATE_FILE")

# Extract individual fields
ENABLED=$(echo "$FRONTMATTER" | grep '^enabled:' | sed 's/enabled: *//' | sed 's/^"\(.*\)"$/\1/')
STRICT_MODE=$(echo "$FRONTMATTER" | grep '^strict_mode:' | sed 's/strict_mode: *//' | sed 's/^"\(.*\)"$/\1/')

# Check if enabled
if [[ "$ENABLED" != "true" ]]; then
  exit 0  # Disabled
fi

# Use configuration in hook logic
if [[ "$STRICT_MODE" == "true" ]]; then
  # Apply strict validation
  # ...
fi

See `examples/read-settings-hook.sh` for complete working example.

From Commands

Commands can read settings files to customize behavior:

---
description: Process data with plugin
allowed-tools: ["Read", "Bash"]
---

# Process Command

Steps:
1. Check if settings exist at `.claude/my-plugin.local.md`
2. Read configuration using Read tool
3. Parse YAML frontmatter to extract settings
4. Apply settings to processing logic
5. Execute with configured behavior

From Agents

Agents can reference settings in their instructions:

---
name: configured-agent
description: Agent that adapts to project settings
---

Check for plugin settings at `.claude/my-plugin.local.md`.
If present, parse YAML frontmatter and adapt behavior according to:
- enabled: Whether plugin is active
- mode: Processing mode (strict, standard, lenient)
- Additional configuration fields

Parsing Techniques

Extract Frontmatter

# Extract everything between --- markers
FRONTMATTER=$(sed -n '/^---$/,/^---$/{ /^---$/d; p; }' "$FILE")

Read Individual Fields

**String fields:**

VALUE=$(echo "$FRONTMATTER" | grep '^field_name:' | sed 's/field_name: *//' | sed 's/^"\(.*\)"$/\1/')

**Boolean fields:**

ENABLED=$(echo "$FRONTMATTER" | grep '^enabled:' | sed 's/enabled: *//')
# Compare: if [[ "$ENABLED" == "true" ]]; then

**Numeric fields:**

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