blackroad-operating-system/MERGE_QUEUE_PLAN.md

🌌 MERGE QUEUE PLAN — Phase Q

BlackRoad Operating System Phase: Q — Merge Queue & Automation Strategy Owner: Operator Alexa (Cadillac) Status: Implementation Ready Last Updated: 2025-11-18

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Executive Summary

Phase Q transforms the BlackRoad GitHub organization from a merge bottleneck into a flowing automation pipeline capable of handling 50+ concurrent PRs from AI agents, human developers, and automated systems.

This plan implements:

• ✅ Merge Queue System — Race-condition-free sequential merging
• ✅ Auto-Merge Logic — Zero-touch merging for safe PR categories
• ✅ Workflow Bucketing — Module-specific CI to reduce build times
• ✅ Smart Labeling — Automatic categorization and routing
• ✅ CODEOWNERS v2 — Module-based ownership with automation awareness
• ✅ Operator Integration — PR events flowing into the OS
• ✅ Prism Dashboard — Real-time queue visualization

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Problem Statement

Current Pain Points

Before Phase Q:

50+ PRs waiting → Manual reviews → CI conflicts → Stale branches → Wasted time

Issues:

1. Race conditions — Merges invalidate each other's tests
2. Stale branches — PRs fall behind main rapidly
3. CI congestion — All workflows run on every PR
4. Manual overhead — Humans gate trivial PRs
5. Context switching — Operators lose flow state
6. No visibility — Queue status is opaque

After Phase Q

PR created → Auto-labeled → Queued → Tests run → Auto-merged → Operator notified

Outcomes:

• ⚡ 10x throughput — Handle 50+ PRs/day
• 🤖 90% automation — Only complex PRs need human review
• 🎯 Zero conflicts — Queue manages sequential merging
• 📊 Full visibility — Prism dashboard shows queue state
• 🚀 Fast CI — Only affected modules run tests
• 🧠 Operator-aware — GitHub events feed into BlackRoad OS

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Architecture

System Components

┌─────────────────────────────────────────────────────────────┐
│                     GitHub PR Event                         │
│         (opened, synchronized, labeled, review)              │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│                   Labeler Action                            │
│   Auto-tags PR based on files changed, author, patterns     │
│   Labels: claude-auto, docs, infra, breaking-change, etc.   │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│              Auto-Approve Logic (if applicable)             │
│   - docs-only: ✓ approve                                    │
│   - claude-auto + tests pass: ✓ approve                     │
│   - infra + small changes: ✓ approve                        │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│                  Workflow Buckets                           │
│   Only run CI for affected modules:                         │
│   backend/ → backend-ci.yml                                 │
│   docs/ → docs-ci.yml                                       │
│   agents/ → agents-ci.yml                                   │
│   blackroad-os/ → frontend-ci.yml                           │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│                    Merge Queue                              │
│   - Approved PRs enter queue                                │
│   - Queue rebases onto main                                 │
│   - Re-runs required checks                                 │
│   - Merges when green                                       │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│              Auto-Merge (if enabled)                        │
│   PRs with auto-merge label merge without human click       │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│             Operator Event Handler                          │
│   backend/app/services/github_events.py receives webhook    │
│   - Logs merge to database                                  │
│   - Notifies Prism Console                                  │
│   - Updates Operator dashboard                              │
└─────────────────────────────────────────────────────────────┘

---

Merge Queue Configuration

What is a Merge Queue?

A merge queue is GitHub's solution to the "stale PR" problem:

Traditional Workflow:

1. PR #1 passes tests on branch feature-a
2. PR #1 merges to main
3. PR #2 (based on old main) is now stale
4. PR #2 must rebase and re-run tests
5. Repeat for every PR → exponential waiting

Merge Queue Workflow:

1. Approved PRs enter a queue
2. GitHub creates temporary merge commits
3. Tests run on the merged state
4. Only green PRs merge sequentially
5. No stale branches, no race conditions

Queue Rules

Merge Queue Settings (.github/merge_queue.yml):

merge_method: squash           # or merge, rebase
merge_commit_message: PR_TITLE
merge_commit_title_pattern: "[%number%] %title%"

# Required status checks (must pass before entering queue)
required_checks:
  - Backend Tests
  - Frontend Validation
  - Security Scan

# Queue behavior
min_entries_to_merge: 0        # Merge immediately when ready
max_entries_to_merge: 5        # Merge up to 5 PRs at once
merge_timeout_minutes: 60      # Fail if stuck for 1 hour

# Branch update method
update_method: rebase          # Keep clean history

Branch Protection Rules (applied via GitHub UI):

• ✅ Require pull request before merging
• ✅ Require status checks to pass
• ✅ Require branches to be up to date
• ✅ Require merge queue
• ✅ Do not allow bypassing (even admins)

---

Auto-Merge Policy

See AUTO_MERGE_POLICY.md for full details.

Safe-to-Merge Categories

Category	Auto-Approve	Auto-Merge	Rationale
Docs-only	✅	✅	No code changes, low risk
Tests-only	✅	✅	Improves coverage, no prod impact
Scaffold/Stubs	✅	✅	Template code, reviewed later
CI/Workflow updates	✅	⚠️ Manual	High impact, human check
Dependency bumps	⚠️ Dependabot	⚠️ Manual	Security check required
Chore (formatting, etc.)	✅	✅	Linters enforce standards
Claude-generated	✅ (if tests pass)	✅	AI-authored, tests validate
Breaking changes	❌	❌	Always human review
Security fixes	❌	❌	Always human review

Auto-Merge Triggers

A PR auto-merges if:

1. ✅ Has label: auto-merge OR claude-auto OR docs-only
2. ✅ All required checks pass
3. ✅ At least one approval (can be bot)
4. ✅ No breaking-change or security labels
5. ✅ Branch is up to date (or in merge queue)

Implementation:

# .github/auto-merge.yml
name: Auto-Merge
on:
  pull_request_review:
    types: [submitted]
  status: {}

jobs:
  auto-merge:
    if: |
      github.event.review.state == 'approved' &&
      contains(github.event.pull_request.labels.*.name, 'auto-merge')
    runs-on: ubuntu-latest
    steps:
      - uses: pascalgn/automerge-action@v0.16.2
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          MERGE_LABELS: auto-merge,claude-auto,docs-only
          MERGE_METHOD: squash

---

Workflow Bucketing

Problem

Before:

• Every PR triggers all CI workflows
• Backend changes run frontend tests
• Docs changes run full test suite
• Result: Wasted CI minutes, slow feedback

Solution

Module-Specific Workflows:

Workflow	Trigger Paths	Jobs
backend-ci.yml	backend/**, requirements.txt	pytest, type check, lint
frontend-ci.yml	blackroad-os/**, backend/static/**	HTML validation, JS syntax
agents-ci.yml	agents/**	Agent tests, template validation
docs-ci.yml	docs/**, *.md	Markdown lint, link check
infra-ci.yml	infra/**, .github/**, ops/**	Config validation, Terraform plan
sdk-ci.yml	sdk/**	Python SDK tests, TypeScript build

Example (backend-ci.yml):

name: Backend CI
on:
  pull_request:
    paths:
      - 'backend/**'
      - 'requirements.txt'
      - 'Dockerfile'
  push:
    branches: [main]
    paths:
      - 'backend/**'

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: '3.11'
      - name: Install dependencies
        run: |
          cd backend
          pip install -r requirements.txt
      - name: Run tests
        run: |
          cd backend
          pytest -v --cov

Benefits:

• ⚡ 3-5x faster CI for most PRs
• 💰 60% cost reduction in CI minutes
• 🎯 Targeted feedback — Only relevant tests run
• 🔄 Parallel execution — Multiple workflows run simultaneously

---

Labeling Strategy

Auto-Labeling

Configuration (.github/labeler.yml):

# Documentation
docs:
  - changed-files:
    - any-glob-to-any-file: ['docs/**/*', '*.md', 'README.*']

# Backend
backend:
  - changed-files:
    - any-glob-to-any-file: 'backend/**/*'

# Frontend / OS
frontend:
  - changed-files:
    - any-glob-to-any-file: ['blackroad-os/**/*', 'backend/static/**/*']

# Infrastructure
infra:
  - changed-files:
    - any-glob-to-any-file: ['.github/**/*', 'infra/**/*', 'ops/**/*', '*.toml', '*.json']

# Agents
agents:
  - changed-files:
    - any-glob-to-any-file: 'agents/**/*'

# Tests
tests:
  - changed-files:
    - any-glob-to-any-file: ['**/tests/**/*', '**/*test*.py', '**/*.test.js']

# Dependencies
dependencies:
  - changed-files:
    - any-glob-to-any-file: ['requirements.txt', 'package*.json', 'Pipfile*']

Manual Labels

Applied by humans or bots:

Label	Purpose	Auto-Merge?
claude-auto	Claude-generated PR	✅ (if tests pass)
atlas-auto	Atlas-generated PR	✅ (if tests pass)
merge-ready	Human approved, safe to merge	✅
needs-review	Requires human eyes	❌
breaking-change	API or behavior change	❌
security	Security-related change	❌
critical	Urgent fix, prioritize	⚠️ Human decides
wip	Work in progress, do not merge	❌

---

CODEOWNERS v2

See updated .github/CODEOWNERS for full file.

Key Changes

Module-Based Ownership:

# Backend modules
/backend/app/routers/          @backend-team @alexa-amundson
/backend/app/models/           @backend-team @data-team
/backend/app/services/         @backend-team

# Operator & Automation
/backend/app/services/github_events.py  @operator-team @alexa-amundson
/agents/                       @agent-team @alexa-amundson

# Infrastructure (high scrutiny)
/.github/workflows/            @infra-team @alexa-amundson
/infra/                        @infra-team
/ops/                          @ops-team @infra-team

# Documentation (low scrutiny)
/docs/                         @docs-team
*.md                           @docs-team

Auto-Approval Semantics:

# Low-risk files — bot can approve
/docs/                         @docs-bot
/backend/tests/                @test-bot

# High-risk files — humans only
/.github/workflows/            @alexa-amundson
/infra/                        @alexa-amundson

---

Operator Integration

GitHub Event Handler

Location: backend/app/services/github_events.py

Functionality:

• Receives GitHub webhook events
• Filters for PR events (opened, merged, closed, labeled)
• Logs to database (github_events table)
• Emits events to Operator Engine
• Notifies Prism Console for dashboard updates

Event Flow:

GitHub Webhook → FastAPI Endpoint → Event Handler → Database + Operator → Prism UI

Example Events:

• pr.opened → Show notification in OS
• pr.merged → Update team metrics
• pr.failed_checks → Alert Operator
• pr.queue_entered → Update dashboard

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Prism Dashboard

Merge Queue Visualizer

Location: blackroad-os/js/apps/prism-merge-dashboard.js

Features:

• Real-time queue status
• PR list with labels, checks, ETA
• Throughput metrics (PRs/day, avg time-to-merge)
• Failure analysis (which checks fail most)
• Operator actions (approve, merge, close)

UI Mockup:

┌─────────────────────────────────────────────────┐
│  MERGE QUEUE DASHBOARD           🟢 Queue Active│
├─────────────────────────────────────────────────┤
│  Queued PRs: 3   |   Merging: 1   |   Failed: 0 │
├─────────────────────────────────────────────────┤
│  #123  [backend] Fix user auth     ⏳ Testing    │
│  #124  [docs] Update API guide     ✅ Ready      │
│  #125  [infra] Add monitoring      🔄 Rebasing   │
├─────────────────────────────────────────────────┤
│  Throughput: 12 PRs/day   Avg Time: 45min       │
└─────────────────────────────────────────────────┘

---

Implementation Checklist

Phase Q.1 — GitHub Configuration

• Enable merge queue on main branch (GitHub UI)
• Configure branch protection rules
• Add required status checks
• Set merge method to squash

Phase Q.2 — Workflow Setup

• Create .github/labeler.yml
• Create .github/merge_queue.yml
• Create .github/auto-merge.yml
• Create .github/auto-approve.yml
• Create bucketed workflows (backend-ci, frontend-ci, etc.)
• Test workflows on sample PRs

Phase Q.3 — Ownership & Policy

• Rewrite .github/CODEOWNERS
• Document auto-merge policy
• Create PR templates with label hints
• Train team on new workflow

Phase Q.4 — Operator Integration

• Create backend/app/services/github_events.py
• Add GitHub webhook endpoint
• Test event flow to database
• Verify Operator receives events

Phase Q.5 — Prism Dashboard

• Create blackroad-os/js/apps/prism-merge-dashboard.js
• Connect to backend API
• Test real-time updates
• Deploy to production

Phase Q.6 — Validation & Tuning

• Monitor queue performance for 1 week
• Adjust timeout and batch settings
• Identify workflow bottlenecks
• Optimize CI times
• Document learnings

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Metrics & Success Criteria

Before Phase Q

Metric	Value
PRs merged per day	~5
Avg time to merge	4-6 hours
CI time per PR	15-20 min (all workflows)
Merge conflicts per week	10+
Manual interventions	90% of PRs

After Phase Q (Target)

Metric	Target
PRs merged per day	50+
Avg time to merge	30-45 min
CI time per PR	3-5 min (bucketed)
Merge conflicts per week	<2 (queue prevents)
Manual interventions	<10% of PRs

Dashboard Metrics

Track in Prism Console:

• Queue depth over time
• Merge throughput (PRs/hour)
• Failure rate by check type
• Auto-merge adoption rate
• Operator time saved (estimated)

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Rollout Plan

Week 1: Setup & Testing

Day 1-2: Configuration

• Deploy all GitHub configs
• Enable merge queue (main branch only)
• Test with 2-3 sample PRs

Day 3-4: Workflow Migration

• Deploy bucketed workflows
• Run parallel with existing CI
• Compare times and results

Day 5-7: Integration

• Deploy Operator event handler
• Test Prism dashboard
• Monitor for issues

Week 2: Gradual Adoption

Day 8-10: Auto-Labeling

• Enable labeler action
• Validate label accuracy
• Adjust patterns as needed

Day 11-12: Auto-Merge (Docs)

• Enable auto-merge for docs-only label
• Monitor for false positives
• Expand to tests-only

Day 13-14: Full Auto-Merge

• Enable claude-auto auto-merge
• Monitor closely
• Adjust policy as needed

Week 3: Optimization

Day 15-17: Performance Tuning

• Analyze queue metrics
• Optimize slow checks
• Reduce timeout values

Day 18-19: Documentation

• Write runbooks for common issues
• Train team on Prism dashboard
• Update CLAUDE.md with new workflows

Day 20-21: Full Production

• Remove old workflows
• Announce to team
• Monitor and celebrate 🎉

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Risk Mitigation

Identified Risks

Risk	Impact	Likelihood	Mitigation
Queue gets stuck	High	Medium	Timeout + manual override
False auto-merges	High	Low	Conservative initial policy
CI failures increase	Medium	Medium	Gradual rollout, monitor closely
Operator overload	Low	Medium	Rate limiting on webhooks
Breaking changes slip through	High	Low	Required breaking-change label

Rollback Plan

If Phase Q causes issues:

1. Disable merge queue (GitHub UI → branch protection)
2. Disable auto-merge (pause workflow)
3. Revert to manual approval (CODEOWNERS update)
4. Keep bucketed workflows (they're strictly better)
5. Investigate and fix before re-enabling

Rollback Time: <5 minutes

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Maintenance & Evolution

Regular Tasks

Daily:

• Check Prism dashboard for queue anomalies
• Review auto-merged PRs (spot check)

Weekly:

• Analyze throughput metrics
• Identify slowest CI checks
• Update labeler patterns as needed

Monthly:

• Review auto-merge policy
• Adjust CODEOWNERS for new modules
• Optimize workflow bucket paths
• Audit GitHub Actions usage

Future Enhancements

Phase Q.7 — Multi-Repo Queues:

• Coordinate merges across blackroad-api, blackroad-operator, etc.
• Prevent dependency conflicts

Phase Q.8 — AI-Powered Triage:

• Lucidia agents auto-review PRs
• Suggest reviewers based on code changes
• Predict merge time

Phase Q.9 — Merge Forecasting:

• ML model predicts queue wait time
• Alerts Operators about upcoming bottlenecks
• Recommends workflow optimizations

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Conclusion

Phase Q transforms GitHub from a manual, bottleneck-prone system into an automated merge pipeline that scales with your AI-powered development velocity.

By combining merge queues, auto-merge logic, workflow bucketing, and Operator integration, we achieve:

• ✅ 10x throughput without sacrificing quality
• ✅ 90% automation for safe PR categories
• ✅ Full visibility via Prism Dashboard
• ✅ Zero conflicts through queue management
• ✅ Fast feedback via targeted CI

This is the foundation for a self-governing engineering organization where AI and humans collaborate seamlessly.

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Phase Q complete, Operator. Your merge queues are online. 🚀

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Last Updated: 2025-11-18 Owner: Operator Alexa (Cadillac) Related Docs: GITHUB_AUTOMATION_RULES.md, AUTO_MERGE_POLICY.md, WORKFLOW_BUCKETING_EXPLAINED.md