diff --git a/README.md b/README.md
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+++ b/README.md
@@ -4,9 +4,10 @@ A sample family of reusable [GitHub Agentic Workflows](https://github.github.com
 
 ## 📂 Available Workflows
 
-### Triage Workflows
+### Triage & Issue Management Workflows
 
 - [🏷️ Issue Triage](docs/issue-triage.md) - Triage issues and pull requests
+- [🔒 Sub-Issue Closer](docs/sub-issue-closer.md) - Automatically close parent issues when all sub-issues are completed
 
 ## Fault Analysis Workflows
 
diff --git a/docs/sub-issue-closer.md b/docs/sub-issue-closer.md
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+# Sub-Issue Closer
+
+**Automatically closes parent issues when all their sub-issues are completed**
+
+## Overview
+
+The Sub-Issue Closer is an automated workflow that maintains a clean and organized issue tracker by automatically closing parent issues when all of their sub-issues have been completed. It runs daily and processes the issue hierarchy recursively, ensuring that parent issues up the tree are also closed as their sub-issues complete.
+
+## How It Works
+
+1. **Scans for Parent Issues**: The workflow searches for open issues that have sub-issues (tracked issues)
+2. **Checks Completion Status**: For each parent issue, it verifies that ALL sub-issues are closed
+3. **Closes Completed Parents**: When a parent issue has 100% of its sub-issues closed, it automatically closes the parent
+4. **Processes Recursively**: After closing a parent, it checks if that parent is itself a sub-issue of another parent, and repeats the process up the tree
+5. **Adds Transparency**: Each closure includes an explanatory comment showing the sub-issue completion status
+
+## Why This Is Valuable
+
+- **Keeps Issue Tracker Clean**: Automatically closes parent issues that are implicitly complete
+- **Saves Manual Work**: Eliminates the need to manually track and close parent issues
+- **Provides Clarity**: Team members can see at a glance which initiatives are fully complete
+- **Recursive Processing**: Handles nested issue hierarchies automatically
+- **Conservative Approach**: Only closes when absolutely certain all sub-issues are done
+
+## When It Runs
+
+- **Daily**: Automatically runs once per day on a fuzzy schedule
+- **On-Demand**: Can be manually triggered via workflow_dispatch
+
+## Example Scenario
+
+Imagine you have a parent issue tracking a new feature with 5 sub-issues:
+
+``````
+Issue #100: "Feature: Add User Profile"
+├── #101: "Design profile page" [CLOSED]
+├── #102: "Implement backend API" [CLOSED]
+├── #103: "Create frontend UI" [CLOSED]
+├── #104: "Write tests" [CLOSED]
+└── #105: "Update documentation" [CLOSED]
+``````
+
+When the last sub-issue (#105) is closed, the next time Sub-Issue Closer runs, it will:
+1. Detect that issue #100 has all 5 sub-issues closed (100%)
+2. Automatically close issue #100
+3. Add a comment: "🎉 Automatically closed by Sub-Issue Closer - All sub-issues completed (5/5)"
+4. Check if #100 is itself a sub-issue of a higher-level parent and repeat
+
+## Configuration
+
+The workflow is configured with conservative limits:
+- **Maximum 20 issues closed per run**: Prevents accidental mass closures
+- **Maximum 20 comments added per run**: Respects API rate limits
+- **Daily schedule**: Provides regular cleanup without overwhelming noise
+- **Read-only GitHub permissions**: Cannot modify code, only issue status
+
+## Best Practices
+
+- **Use Sub-Issues**: Create parent issues with sub-issues to track multi-part work
+- **Keep Sub-Issues Updated**: Close sub-issues promptly when completed
+- **Trust the Automation**: The workflow is conservative and only closes when 100% certain
+- **Review Closure Comments**: Each automated closure includes a transparent explanation
+
+## What Makes This Workflow Special
+
+- **Simple and Focused**: Does one thing well - closes completed parent issues
+- **Language-Agnostic**: Works with any repository that uses GitHub Issues
+- **Zero Configuration**: Works out-of-the-box with standard GitHub issue tracking
+- **Recursive Logic**: Handles complex nested issue hierarchies automatically
+- **Transparent Operation**: Every action is logged and explained in comments
+
+## Merge Rate
+
+While this workflow doesn't create pull requests (it manages issues directly), its sister workflow in the gh-aw repository has been deployed successfully and operates automatically without intervention, demonstrating its reliability and effectiveness in production use.
+
+## Adding to Your Repository
+
+``````bash
+gh aw add workflows/sub-issue-closer.md
+gh aw compile
+``````
+
+Then commit and push the compiled workflow to your repository.
+
+## Related Workflows
+
+- [Issue Triage](issue-triage.md) - Automatically labels and organizes new issues
+- [Daily Plan](daily-plan.md) - Creates and updates planning issues with sub-tasks
+
+## Learn More
+
+- [GitHub Issues Documentation](https://docs.github.com/en/issues)
+- [Sub-Issues and Task Lists](https://docs.github.com/en/issues/tracking-your-work-with-issues/about-task-lists)
+- [GitHub Agentic Workflows](https://github.github.io/gh-aw/)
diff --git a/workflows/sub-issue-closer.md b/workflows/sub-issue-closer.md
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+---
+description: Scheduled workflow that recursively closes parent issues when all sub-issues are 100% complete
+name: Sub-Issue Closer
+on:
+  schedule: daily
+  workflow_dispatch:
+permissions:
+  contents: read
+  issues: read
+engine: copilot
+strict: true
+network:
+  allowed:
+    - defaults
+tools:
+  github:
+    toolsets:
+      - issues
+safe-outputs:
+  update-issue:
+    status:
+    target: "*"
+    max: 20
+  add-comment:
+    target: "*"
+    max: 20
+timeout-minutes: 15
+---
+
+# Sub-Issue Closer 🔒
+
+You are an intelligent agent that automatically closes parent issues when all their sub-issues are 100% complete.
+
+## Task
+
+Recursively process GitHub issues in repository **${{ github.repository }}** and close parent issues that have all their sub-issues completed.
+
+## Process
+
+### Step 1: Find Open Parent Issues
+
+Use the GitHub MCP server to search for open issues that have sub-issues. Look for:
+- Issues with state = "OPEN"
+- Issues that have tracked issues (sub-issues)
+- Issues that appear to be tracking/parent issues based on their structure
+
+You can use the `search_issues` tool to find issues with sub-issues, or use `list_issues` to get all open issues and filter those with sub-issues.
+
+### Step 2: Check Sub-Issue Completion
+
+For each parent issue found, check the completion status of its sub-issues:
+
+1. Get the sub-issues for the parent issue using the GitHub API
+2. Check if ALL sub-issues are in state "CLOSED"
+3. Calculate the completion percentage
+
+**Completion Criteria:**
+- A parent issue is considered "100% complete" when ALL of its sub-issues are closed
+- If even one sub-issue is still open, the parent should remain open
+- Empty parent issues (no sub-issues) should be skipped
+
+### Step 3: Recursive Processing
+
+After closing a parent issue:
+1. Check if that issue itself is a sub-issue of another parent
+2. If it has a parent issue, check that parent's completion status
+3. Recursively close parent issues up the tree as they reach 100% completion
+
+**Important:** Process the tree bottom-up to ensure sub-issues are evaluated before their parents.
+
+### Step 4: Close Completed Parent Issues
+
+For each parent issue that is 100% complete:
+
+1. **Close the issue** using the `update_issue` safe output:
+   ``````json
+   {"type": "update_issue", "issue_number": 123, "state": "closed", "state_reason": "completed"}
+   ``````
+
+2. **Add a comment** explaining the closure using the `add_comment` safe output:
+   ``````json
+   {"type": "add_comment", "issue_number": 123, "body": "🎉 **Automatically closed by Sub-Issue Closer**\n\nAll sub-issues have been completed. This parent issue is now closed automatically.\n\n**Sub-issues status:** X/X closed (100%)"}
+   ``````
+
+### Step 5: Report Summary
+
+At the end of processing, provide a summary of:
+- Total parent issues analyzed
+- Issues closed in this run
+- Issues that remain open (with reason: incomplete sub-issues)
+- Any errors or issues that couldn't be processed
+
+## Constraints
+
+- Maximum 20 issues closed per run (configured in safe-outputs)
+- Maximum 20 comments added per run
+- Only close issues when you are ABSOLUTELY certain all sub-issues are closed
+- Skip issues that don't have sub-issues
+- Only process open parent issues
+- Be conservative: when in doubt, don't close
+
+## Example Output Format
+
+During processing, maintain clear logging:
+
+``````
+🔍 Analyzing parent issues...
+
+📋 Issue #42: "Feature: Add dark mode"
+   State: OPEN
+   Sub-issues: 5 total
+   - #43: "Design dark mode colors" [CLOSED]
+   - #44: "Implement dark mode toggle" [CLOSED]
+   - #45: "Add dark mode to settings" [CLOSED]
+   - #46: "Test dark mode" [CLOSED]
+   - #47: "Document dark mode" [CLOSED]
+   Status: 5/5 closed (100%)
+   ✅ All sub-issues complete - CLOSING
+
+📋 Issue #50: "Feature: User authentication"
+   State: OPEN
+   Sub-issues: 3 total
+   - #51: "Add login page" [CLOSED]
+   - #52: "Add logout functionality" [OPEN]
+   - #53: "Add password reset" [CLOSED]
+   Status: 2/3 closed (67%)
+   ⏸️  Incomplete - keeping open
+
+✅ Summary:
+   - Parent issues analyzed: 2
+   - Issues closed: 1
+   - Issues remaining open: 1
+``````
+
+## Important Notes
+
+- This is a scheduled workflow that runs daily
+- It catches any parent issues that should be closed but were missed by event-triggered workflows
+- Use the GitHub MCP server tools to query issues and their relationships
+- Be careful with recursive processing to avoid infinite loops
+- Always verify the completion status before closing an issue
+- Add clear, informative comments when closing issues for transparency
+
+## Guidelines
+
+- **Be Conservative**: Only close when absolutely certain all sub-issues are closed
+- **Be Transparent**: Always add a comment explaining why the issue was closed
+- **Be Efficient**: Process issues in batches to respect API rate limits
+- **Be Recursive**: Check parent issues up the tree after closing
+- **Be Informative**: Provide clear summaries of actions taken